Mt. Cuba Center Native Bee Survey by Mt. Cuba Center

Mt. Cuba Native Bee Survey: 2018-2019 Final Report

Mt. Cuba Native Bee Survey 2018-2019 Final Report

Prepared for: Mount Cuba Center December 2020

Recommended Citation: Sarver, Matthew J. 2020. Mt. Cuba Native Bee Survey 2018-2019 Final Report. Report to Mount Cuba Center, Inc. Sarver Ecological, LLC: Wilmington, DE.

TABLE OF CONTENTS Table of Contents ............................................................................................................................................................................................................ i Executive Summary ........................................................................................................................................................................................................ 1 Background ...................................................................................................................................................................................................................... 3 Project Goals and Objectives ................................................................................................................................................................................... 3 What Are Native Bees? ............................................................................................................................................................................................. 3 Life Histories .......................................................................................................................................................................................................... 3 Methods............................................................................................................................................................................................................................ 4 Survey Methods .......................................................................................................................................................................................................... 4 Sampling Locations ............................................................................................................................................................................................... 4 General Methods ................................................................................................................................................................................................... 6 Excluded Species ................................................................................................................................................................................................... 6 Pan Trapping .......................................................................................................................................................................................................... 6 Targeted Netting .................................................................................................................................................................................................... 6 Processing and Identification .............................................................................................................................................................................. 6 Survey Results ................................................................................................................................................................................................................. 7 Species Diversity and Abundance ........................................................................................................................................................................... 7 Plant Associations and Specialization ..................................................................................................................................................................... 8 Pan Trapping Site Comparisons .............................................................................................................................................................................. 9 New Delaware State Records ................................................................................................................................................................................. 10 Bee Diversity ................................................................................................................................................................................................................. 11 Colletidae ................................................................................................................................................................................................................... 11 Plasterer Bees (Genus Colletes) ........................................................................................................................................................................... 11 Masked Bees (Genus Hylaeus) ............................................................................................................................................................................ 12 Family Apidae ........................................................................................................................................................................................................... 13 Digger Bees (Genus Anthophora) .................................................................................................................................................................... 13 Bumble Bees (Genus Bombus) ............................................................................................................................................................................ 13 Large Carpenter Bees (Genus Xylocopa) ........................................................................................................................................................... 14 Small Carpenter Bees (Genus Ceratina) ............................................................................................................................................................ 14 Cuckoo Bees (Genus Nomada)........................................................................................................................................................................... 15 Long-horned Bees (Genera Eucera, Melissodes) ................................................................................................................................................ 16 Other Apidae (Genera Peponapis, Ptilothrix, Svastra) .................................................................................................................................. 16 Family Halictidae ...................................................................................................................................................................................................... 17 Furrow Bees (Genus Halictus) ............................................................................................................................................................................ 17 Metallic Green Bees (Genera Auchlora, Augochorella, Augochloropsis, and Agapostemon)............................................................................... 18 Metallic Sweat Bees (Genus Lasioglossum, Subgenus Dialictus) ...................................................................................................................... 19

Sweat Bees (Genus Lasioglossum, Other Subgenera) ....................................................................................................................................... 20 Blood Bees (Genus Sphecodes)............................................................................................................................................................................. 20 Andrenidae ................................................................................................................................................................................................................ 21 Miner Bees (Genera Andrena and Pseudopanurgus) ........................................................................................................................................... 21 Family Megachilidae ................................................................................................................................................................................................. 23 Mason Bees (Genus Osmia) ................................................................................................................................................................................ 23 Resin Bees and Others (Genera Chelostoma, Heriades, Hoplitis) ...................................................................................................................... 23 Leaf-cutter Bees and Cuckoo Leaf-cutter Bees: Genera Megachile and Coelioxys ........................................................................................ 24 Woolcarder Bees (Genus Anthidium) ................................................................................................................................................................ 24 Selected Plants and Important Bee Associations at Mt. Cuba ............................................................................................................................... 25 Woody Plants ............................................................................................................................................................................................................ 25 Castanea (Chestnuts)............................................................................................................................................................................................. 25 Cercis (Redbud) ..................................................................................................................................................................................................... 25 Cornus (Swida) (Shrub Dogwoods) ..................................................................................................................................................................... 25 Hydrangea (Hydrangeas) ....................................................................................................................................................................................... 25 Rhododendron (Azaleas & Rhododendrons) ....................................................................................................................................................... 25 Rubus (Blackberries and Raspberries) ............................................................................................................................................................... 26 Salix (Willows) ...................................................................................................................................................................................................... 26 Perennial Forbs ......................................................................................................................................................................................................... 27 Cardamine (Toothwort) ........................................................................................................................................................................................ 27 Cirsium (Thistles) .................................................................................................................................................................................................. 27 Claytonia (Spring Beauty) ..................................................................................................................................................................................... 27 Eurybia (Wood Asters) ........................................................................................................................................................................................ 27 Helianthus (Sunflowers)........................................................................................................................................................................................ 27 Heuchera (Alumroot)............................................................................................................................................................................................. 27 Hydrophyllum (Waterleaf)...................................................................................................................................................................................... 28 Mertensia (Bluebells) ............................................................................................................................................................................................. 28 Packera (Golden Ragwort) .................................................................................................................................................................................. 28 Penstemon (Beardtongues) .................................................................................................................................................................................... 28 Phacelia (Scorpionweed) ....................................................................................................................................................................................... 28 Polemonium (Jacob’s Ladder)................................................................................................................................................................................ 28 Rudbeckia (Black-eyed Susans and Others) ....................................................................................................................................................... 29 Solidago and Euthamia (Goldenrods) .................................................................................................................................................................. 29 Symphyotrichum (Asters) ........................................................................................................................................................................................ 29 Uvularia (Bellworts) .............................................................................................................................................................................................. 29 Veronicastrum (Culver’s Root) ............................................................................................................................................................................. 29 Vernonia (Ironweed) ................................................................................................................................................................................................ 29 Viola (Violets) ....................................................................................................................................................................................................... 30 Zizia (Golden Alexanders).................................................................................................................................................................................. 30 Literature Cited.............................................................................................................................................................................................................. 31

Appendix A. Mid-Atlantic Specialist Bees and their Host Associations ......................................................................................................... 34 Appendix B. Bee Collections by Host Plant ........................................................................................................................................................ 46

iii

Executive Summary This study of Mt. Cuba’s gardens and outlying natural lands documented 3,493 individual bees of 135 species during 2018-19. Due to the diverse and special nature of Mt Cuba, as well as the fact that Delaware has generally been undersampled for bees, this project represents one of the most important bodies of information ever compiled for Delaware’s bees. Among the important results were a number of very exciting finds, including: Project Highlights •

15 species of native bees - more than 10% of the species found - were not previously known to occur in the state of Delaware (“New State Records”) See page 10.

•

Discovery of the only known population of the Alumroot specialist, the Summer Cellophane Bee, Colletes aestivalis in the northeast region. Nearest recent records are from the Shenandoah Mts. of Virginia. This rare species is of high conservation concern throughout the northeast. See page 11.

•

Major range extension of 365 miles for the Polemonium specialist Andrena polemonii, the Jacob’s Ladder Miner Bee and the first ever records east of the Appalachians. A robust population is fueled by the extensive Polemonium plantings in the garden. See page 22.

•

Major range extension of 350 miles for the masked bee Hylaeus fedorica, first ever record east of the Appalachians. This specimen has been sent to taxonomic experts in Tornto for DNA barcoding to confirm its identity. See page 12.

•

23 species of pollen specialist bees that depend on one or a few plant genera for their survival. Several of these species had not been documented before in Delaware.

Key Recommendations 1. Monitoring Continue to monitor native bee populations at Mount Cuba. •

Long-term monitoring: Repeat bee bowl surveys at the 4 permanent transect locations established in 2019 in the future, preferably for two years in a row, every five to ten years.

•

Continue targeted surveys for remaining specialist bees that have not been documented to date and continue to expand the sample size of surveys on native plant species.

2. Plant Selection in the Gardens Incorporate bee diversity and host plants of specialist bees into decision-making about volumes of plant material in the gardens. See pages 25-30. •

Maintain high floral area for important host species of rare and uncommon bees, including Polmemonium reptans, Uvularia spp., Penstemon spp., and others.

•

Increase floral area of the straight species Heuchera americana to support the regionally significant Colletes aestivalis population and promote H. americana as a straight species in the nursery trade.

3. Natural Areas Restoration and Plant Selection Incorporate bee diversity and host plants of specialist bees into decision-making about volumes of plant material in natural areas restoration. See pages 25-30. •

Focus heavily on increasing the floral area and diversity of late summer and fall composites (Solidago, Symphyotrichum, Vernonia, Helianthus, Cirsium, etc.) as appropriate. Helianthus is likely a particularly important gap to fill as it is underplanted and does not seem to “turn up” on its own very often.

•

Plant woody species such as Salix, Cornus, and Rubus that support bee diversity as well as specialist bees in shrub and edge plantings.

4. Education and Outreach Incorporate the findings of this work into education and outreach components for garden visitors and conservation landowners. •

Create educational publication on native bees and the plants that support them.

Conclusion Due to the high density and diversity of native plant species in Mt. Cuba’s naturalistic gardens, as well as the extensive contiguous natural areas (including floodplain habitats of the Red Clay Creek and rare habitats like Piedmont seepage meadows), management and strategic restoration of Mount Cuba lands has unique potential to host important source populations of a number of rare native bee species. Mount Cuba also presents an unusual opportunity for long-term longitudinal study and monitoring of native bees at permanent sites. Mrs. Copeland’s vision has proven to be not only a world-class native plant garden, but a critical ark for the native bee fauna of the Piedmont. We look forward to continuing to work with Mt Cuba to better understand the native bees of this ecoregion and their critical relationships with our native flora.

Background Project Goals and Objectives The goal of this project was to conduct a faunal inventory of native bees on Mount Cuba Lands and to document the bee assemblages of various habitats at Mount Cuba. A secondary goal was to specifically survey for rare and uncommon specialist bees that are restricted to using a limited range of host species for pollen.

What Are Native Bees? Bees belong to the insect Order Hymenoptera, which also includes wasps, hornets and ants. When most people think of bees, they imagine boxes full of frames dripping with honey, with bees buzzing in and out of the entrance. Apis mellifera, the European honey bee, is a non-native bee brought to North America in the 1600s by European colonists, to provide settlers with honey and wax, and to help pollinate their crops. However, few people realize that there are some 4000 species of bees in North America, and approximately 450 species in northeastern North America. Pennsylvania alone is home to over 370 species of bees (Donovall and van Engelsdorp 2010), and there are over 200 species known from Delaware (Ascher and Pickering 2020). North American bee diversity is organized into six families (see Table 1).

Table 1. Family-level Diversity of Native Bees of North America

Andrenidae

Miner Bees

Apidae

Bumble Bees, Carpenter Bees, Cuckoo Bees, etc.

Colletidae

Plasterer Bees, Masked Bees, etc.

Halictidae

Sweat Bees

Megachilidae

Leafcutter Bees, Mason Bees

Melittidae

Oil-collecting Bees

Life Histories Most native bees are solitary, meaning that individual females lay eggs that they alone provision with pollen. Approximately 20% of 400 northeastern native bee species are cleptoparasitic (laying eggs in nests of other bees) (Fowler 2016). A few groups in the family Apidae exhibit sociality, notably the bumblebees, which have a eusocial hive structure, and the small carpenter bees, which are considered subsocial. Other groups that exhibit sociality in some species include the genera Lasioglossum, Augochlorella and Halictus in the Halictidae family.

Methods Survey Methods Bees were collected between March 19, 2018 and October 2, 2019 at Mount Cuba Center.

Sampling Locations Mount Cuba Center manages over 1,000 acres of natural lands in the Piedmont physiographic province. Since the project goal was to develop an initial native bee faunal survey and species list for the site, with an emphasis on oligolectic (specialist) species, in 2018 different sampling locations chosen throughout the season to maximize the the return on time invested. More sampling effort was made in forested habitats in spring, with effort shifting to more open canopy habitats in summer and fall. Three main sampling localities were explored, representing three very different habitat types: two natural area sites and one heavily managed native garden. In 2019, all three of these sites were investigated throughout the full season using pan trap arrays.

Main Garden The first locality, where the majority of netting on targeted plants occurred, was the main gardens at Mount Cuba Center, with effort focused primarily on the core garden areas southwest of the main house, including the Woods Path, Meadow Garden, Trillium Garden, West Slope Path and Pond areas, with a smaller amount of effort on the formal garden area. Some early spring pilot sampling occurred at an area on the east side of the main house, and a few targeted collections also occurred at the garden adjacent to the Entrance Gate. These gardens are characterized by mature tulip poplar (Liriodendron tulipifera) forest with numerous artificially maintained openings and ample herbaceous and understory native plant species as well as a small herbaceous meadow. The Main Garden was sampled during 2019 using two discrete transects, one (Woods Path) along the full length of the Woods Path and one (Meadow Garden) extending from near the eastern terminus of the Woods Path, along the main path through the Meadow Garden, and then turning west along the ecotone of meadow and forest along the Dogwood Path to the moss garden.

Floodplain Area The floodplain of the Red Clay Creek east of the garden was chosen as one of the sampling localities in the natural areas of Mount Cuba due to its high volume of spring ephemeral flora and intact native riparian canopy. This site, like may floodplains in the Delaware piedmont, is heavily impacted by the non-native invasive plant species lesser cealandine (Ficaria verna) and Pachysandra (Pachysandra terminalis), both of which outcompete native ground flora. For several years, the density of Ficaria has been controlled by periodic chemical treatments which have allowed native Mertensia virginica to continue to dominate the herbaceous layer of the site. Other persistent natives at low densities are Claytonia virginica and Polemonium reptans.

Red Clay Reservation Much of the habitat in the Red Clay Reservation lands recently acquired by Mount Cuba is either successional forests with a high abundance of nonnative plants, or cool season grass hayfields. The small remnant natural area that was chosen for this survey due to its high diversity and abundance of native plant species is a wet seepage meadow at the headwaters of a first order piedmont stream. This site is characterized by a mix of herbaceous wet meadow vegetation (Persicaria sagittata, Eleocharis sp., Carex sp., Juncus effusus, Vernonia noveboracensis, Asclepias incarnata, Asclepias syriaca, Mimulus ringens, etc.) and is fringed by woody species including Salix nigra, Cornus amomum, Prunus sp., etc. The site is invaded by low to moderate amounts of both Japanese stiltgrass (Microstegium vimineum) and hairy jointgrass (Arthraxon hispidus).

Figure 1. Location of Core Transect Sampling Sites at Mt. Cuba Center.

General Methods Excluded Species European honeybees were not a focus of this survey and in order to simplify field protocols and save processing time they were not intentionally collected or recorded when encountered, those some were captured incidentally in pan traps and during netting. The eastern carpenter bee, Xylocopa virginica, which is readily identifiable in the field, was not collected or recorded since it is a common generalist.

Pan Trapping Pan traps consisting of 3.25 oz plastic cups were deployed to passively capture native bees. These “bee bowls” have the interior of the cup painted with UVreflecting fluorescent paint, either yellow, blue, or white, the three colors most attractive to bees. Bowls were partially filled with water to which a small quanitity of Dawn Ultra liquid dishsoap was added to break the suface tension.

Figure 2. Conducting bee netting surveys Photo: Hannah B. Greenberg

Because 2018 was a pilot year for this study, we deployed a single transect of bee bowls at several different sites throughout the season, with the intention of capturing maximum species diversity in a single season. The results of this experimentation were used to inform the selection of four permanent transect locations, at which bowls were deployed concurrently in 2019 to establish a longterm diversity and abundance baseline for future longitudinal study.

Targeted Netting Bees were netted on blooming plants that were specifically chosen for sampling for one of the following reasons: a.) known status as a pollen host for specialist bees of the region, b.) observed as relatively highly attractive to a variety of bee morphospecies, or c.) ubiquitous species in the plant community and apparently attractive to bees. Additionally, opportunistic captures of bees on nontargeted plants, in flight, or basking on vegetation were also made.

Processing and Identification All bees collected were pinned or pointed and identified to species when possible. Species determinations followed Mitchell (1960, 1962), Ascher and Pickering (2020), and Gibbs (2010, 2011). All identifications were confirmed by S. Droege. Males of the Andrena subgenus Trachandrena were not identifiable to species at this time, nor were members of the bidentate group of Nomada. Common names used in this report follow existing names from Natureserve’s Explorer 2.0 database or from Bugguide.net. In cases where no common name existed from those sources, we have translated the Latin species name as closely as possible to a common name.

Survey Results Species Diversity and Abundance We collected 3,493 individual bees of 134 species and 5 families. In addition, the common Eastern Carpenter Bee was not collected, but was frequently observed, bringing the total documented bee species diversity at Mt Cuba to 135 species, including 6 non-native, introduced species and 131 native species. 26 of the 135 species we documented were represented by a single specimen, reflecting the relatively large contribution of rare species to total bee diversity at most sites, including Mt. Cuba. This singleton proportion (.194) falls at the lower end of the range reported by Williams et al. (2001) in a survey of global bee studies. The detected species richness of 135 sitewide is comparable to studies of large natural areas in the Mid-Atlantic region (Giles & Ascher 2006, Winfree et al. 2007). 31 species were only captured by netting while 35 species were only captured in pan traps (see Table 2). Table 2. Summary of Bee Captures and Species Diversity by Collection Method Collection Method

No. of Individuals

Total Species

Unique Species

Pan Trap

2,213

87 (64%)

35 (26%)

Hand Net

1,280

98 (73%)

31 (23%)

Figure 3 visually represents the total species detected from all sampling methods at each of the three major sampling areas: the Mount Cuba Garden, and the two Natural Areas sites, the Floodplain and the Red Clay Reservation Wet Meadow. Because sampling methods and effort were not consistent between sites and years, a statistical comparison of total observed species richness is not possible using rarefaction or related methods, which require that collection methods be identical between sites (Gotelli and Colwell 2011). However, it is readily apparent that the garden hosts exceptional bee diversity, but that all three areas contributed unique species to the survey.

Observed Species Richness by Site 120 100 80 60 40 20 0 Main Garden

Floodplain Area Unique Species

Red Clay Reservation

Shared Species

Figure 3. Observed Species Richness by Site, all years and sampling methods.

Table 3. Abundance (Individuals) of the Top Ten Bee Species in the Survey Andrena carlini

257

Lasioglossum quebecense

215

Eucera hamata

185

Ceratina calcarata

183

Augochlorella aurata

169

Andrena violae

144

Andrena erigeniae

124

Augochlora pura

116

Lasioglossum trigeminum

Bombus impatiens

Plant Associations and Specialization We collected bees from a total of 106 different plant species. The plants are listed in Appendix B. Appendix A includes all known specialist bees from the Mid-Atlantic, with the species we detected in our survey indicated in green, and other likely species that could occur at Mount Cuba in blue. In total, we documented 23 species of oligolectic (specialist) bees, which represents 17% of the total bee fauna detected, a figure that is generally in line with the relative proportion of specialists in other faunal surveys, as reviewed by Danforth et al. (2019).

Pan Trapping Site Comparisons In 2019, simultaneous deployment of identical transects of 30 “bee bowl” pan traps on the same sampling days at four transect sites allowed us to statistically compare diversity metrics. To compare the diversity of the assemblages sampled at these four sites, we used the rarefaction and extrapolation approach described by Chao et al. (2014) to estimate Hill numbers and associated confidence intervals using the iNext software package (Chao et al. 2016). We also used iNext to generate estimated diversity profiles (Chao and Jost 2015) for each site. Sample completeness curves were comparable for each site, indicating sufficient sample size to make comparisons of diversity. Our analyses highlight the significance for bees of the area sampled by the Meadow Garden transect (the Meadow Garden proper and the adjacent ecotones along the Dogwood Path). With high relative species richness as well as high evenness, the diversity of the assemblage inhabitating the meadow and adjacent forest ecotones was significantly higher than the other three transect sites. The floodplain transect had the lowest diversity of all four transects, but it did contribute unique species to the survey.

Hill’s Diversity, q0 (Species Richness)

Hill’s Diversity, q2 (Simpson Diversity)

Hill’s Diversity, q1 (Shannon Diversity)

Biodiversity Profile - Estimated

Figure 4. Interpolation and Extrapolation curves of Hill’s diversity numbers for species assemblages of the four 2019 pan trap sampling sites (Floodplain, Red Clay Reservation Wet Meadow, Meadow Garden, and Woods Path) and the asymptotic Biodiversity Profile for Hill numbers q³0. Colored shading corresponds to 95% confidence intervals. The Meadow Garden transect was significantly more diverse than all other sites.

New Delaware State Records Due to the diverse and special nature of Mt Cuba, as well as the fact that Delaware has generally been undersampled for bees, this project generated a remarkable list of new state records, summarized here. 1. Andrena cornelli – This Rhododendron specialist was collected on Rhododendron periclymenoides and Rhododendron vaseyi, which are cultivated in the gardens. It is known from nearby Cecil and Caroline counties in Maryland. 2. Andrena dunningi – This large Melandrena species was collected from Mertensia virginica at the Floodplain site along the Red Clay, as well as in a pan trap on the Woods Path, where it may also have been using Mertensia. 3. Andrena nigrae – This pollen specialist on willows is uncommon in the region and was previously unrecorded in Delaware. We found 17 of them in a small amount of sampling on Salix nigra on Barley Mill Rd near the Floodplain area. 4. Andrena platyparia – This species specializes on the shrubby dogwoods (Cornus subgenus Swida) and our first Delmarva records were found on blooming Silky Dogwood (Cornus amomum) at the Red Clay wet meadow. 5. Andrena polemonii – This monolectic bee was not previously known east of West Virginia and Ohio, so the numerous specimens from the Mt Cuba garden represent an extension of the known range of the species by approximately 365 miles. 6. Andrena rehni - This chesnut pollen specialist was thought to have declined drastically with the demise of the American Chestnut until fairly recently when it has been found with increasing frequency on chinkapin. We documented Delaware’s first records on hybrid chestnuts at the Red Clay Reservation. 7. Andrena uvulariae – Though somewhat widespread geographically, this bellwort (Uvularia) specalist is rarely collected, with only a handful of records in MD, PA and NJ. One individual was collected on toothwort (Cardamine concatenata) in the vicinity of Uvularia in the garden in 2018, and three more were collected in pan traps adjacent to Uvularia at the edge of the meadow garden in 2019. 8. Ceratina mikmaqi – This relatively common species was split in 2011, and our study was the first to document it in Delaware since its recognition as a new species. It is likely that existing museum records will eventually be identified to this species. 9. Hylaeus fedorica – This new state record, a female, is the first time this species of masked bee has been recorded east of the Appalachians and would be a major range extension for the species. The specimen, from pan traps in the Floodplain, is being sent for DNA barcoding to confirm the identification. 10. Lasioglossum admirandum – This relatively uncommon Lasioglossum species was documented by one specimen each from pan traps in the Meadow Garden, Red Clay Wet Meadow, and the Floodplain. 11. Lasioglossum leucozonium – This is widely distributed Holarctic species that for some reason had not been recorded in Delaware previously. 12. Lasioglossum lionotum – A single individual collected from Eupatorium perfoliatum at the Red Clay Reservation Wet Meadow. This species is a social parasite of the ground-nesting social Lasioglossum imitatum, and is thus apparently rarely collected. There are a handful of records in the Mid-Atlantic. 13. Lasioglossum rozeni – This uncommon species was described for the first time by Gibbs (2011) and is believed to be a parasite on other Dialictus species. 14. Megachile mucida – This legume-associated leaf-cutter bee was collected for the first time in Delaware from Tephrosia virginiana in the rock garden at Mt Cuba. 15. Osmia distincta – Four specimens of this beardtongue specialist were collected on three different Penstemon species in the gardens. The closest prior record is from Cecil County, MD.

Bee Diversity Colletidae Plasterer Bees (Genus Colletes) The Plasterer Bees are sometimes called cellophane bees due to the plastic-like film they secrete for the lining of their nests. Many are specialists. Among the most important and notable discoveries of the current project is the presence of a population of Colletes aestivalis Patton, a rare specialist on Heuchera (Saxifragaceae). This species, though documented historically from Delaware and as far north as Massachusetts, is rare throughout its range. Gibbs et al. (2017) stated “There are very few recent records of C. aestivalis Patton and none from Michigan or, to our knowledge, from anywhere in the Northeastern United States. We therefore regard it as being of conservation concern.” Subsequent sampling has generated a handful of recent records from the Ridge and Valley ecoregion of Virginia and Tennessee (Ascher and Pickering 2020), but to our knowledge the Mt Cuba population represents the only extant population documented in the Piedmont or Northern Piedmont ecoregions, and the only recent records northeast of the Shenandoah region of Virginia. The species was among several bees included as a Species of Greatest Conservation Need (SGCN) in the 2015 Delaware Wildlife Action Plan on the basis of its rarity in the northeast (DNREC 2015). In both 2018 and 2019, we observed numerous female C. aestivalis patrolling and visiting patches of Heuchera americana along the Woods Path and the northern end of the Dogwood Path within the Main Garden. Females were readily apparent in flight due to the bright orange color of the pollen loads carried in their scopae, indicating, as expected, that their pollen loads were primarily composed of distinctive orange pollen from the blooming Heuchera. Near the host plant, we observed what appeared to be agonistic behavior between females, including chases, grappling, and tumbling to the ground. These behaviors may have been motivated by resource defense of the relatively scarce hostplant patches. Table 4. Plasterer Bees: Genus Colletes (3) Colletes aestivalis

Summer Cellophane Bee

Colletes inaequalis

Unequal Cellophane Bee

Colletes thoracicus

Rufous-backed Cellophane Bee

Figure 5. Colletes aestivalis feeding on Heuchera at Mt. Cuba (left), a male C. aestivalis (right) from the USGS BIML.

Masked Bees (Genus Hylaeus) The masked bees are small, black and yellow bees typically found on mid to late summer composites. Hylaeus modestus and Hylaeus affinis are similar and the females were not identified to species in this study. The discovery of a presumed Hylaeus fedorica during this project constitutes a significant range extension for the species. The specimen has been photographed (see below) and is being sent to Dr. Laurance Packer at York University in Toronto for DNA barcoding. If confirmed to indeed be H. fedorica, this would represent a range extension of nearly 700 miles from the nearest record on the border of Ohio and West Virginia. Table 5. Masked Bees: Genus Hylaeus (3) Hylaeus affinis/modestus (females)

Hylaeus fedorica

Fedor Masked Bee

Hylaeus mesillae

Mesilla Masked Bee

Hylaeus modestus

Modest Masked Bee

Figure 6. Images of female masked bee identified by Sam Droege as Hylaeus fedorica, the first record of the species east of the Appalachian Mountains. Note the distinctively rounded face shape, atypical for this subgenus. The female of this species is most similar to another rare species, H. saniculae. Specimen USGS_DRO621851. Photo: USGS Bee Inventory and Monitoring Laboratory.

Family Apidae Digger Bees (Genus Anthophora) Anthophora terminalis excavates nests in a variety of wood substrates, including the stems of Sumac and in coarse woody debris such as fallen logs and driftwood (Satyshur and Orr 2020). Table 6. Digger Bees: Genus Anthophora (1) Anthophora terminalis

Orange-tipped Wood-digger

Bumble Bees (Genus Bombus) The large and charismatic bumble bees are the most recognizable and well-known group of native bees. Preliminary surveys at Mount Cuba resulted in the collection of 107 specimens of Bombus in 2018. We collected a number of bumble bees early in the 2018 season (including some queens) to document species diversity and vernal plant associations, in 2019, we did not collect any Bombus prior to early June 2019 so as not to deplete populations by overcollection. We added an additional 96 specimens in 2019, but only one new species, B. fervidus, found in both the Main Garden and the Red Clay Reservation fields. We did not collect any cuckoo bumble bees (subgenus Psithyrus) although these parasitic bees surely occur in low numbers and should be searched for specifically.

Table 7. Bumble Bees: Genus Bombus (5)

Bombus bimaculatus

Two-spotted Bumble Bee

Bombus fervidus

Yellow Bumble Bee

Bombus griseocollis

Brown-belted Bumble Bee

Bombus impatiens

Common Eastern Bumble Bee

Bombus perplexus

Perplexing Bumble Bee

Figure 7. American Bumble Bee (Bombus pensylvanicus) nectaring on red clover (Trifolium pratense) Photo: Hannah B. Greenberg / Sarver Ecological, LLC

Large Carpenter Bees (Genus Xylocopa) This genus is represented in Delaware by a single species, the eastern carpenter bee (Xylocopa virginica). These very large bodied, hairy bees are often mistaken for bumble bees. They are relatively common at Mt Cuba, however they were not collected as part of this study due to the fact that they are not typically captured in bowls, and since they are a common generalist that is readily identifiable by sight, it was not necessary to collect them during our individual plant netting studies. The non-native giant resin bee (Megachile sculpturalis), present in Delaware, but not yet found at Mount Cuba, has been documented driving eastern carpenter bees from their nests and may be a threat to this species in the future. Table 8. Large Carpenter Bees: Genus Xylocopa (1) Xylocopa virginica

Eastern Carpenter Bee

Frequently observed

Small Carpenter Bees (Genus Ceratina) These tiny blue bees are rather unlike most other bees in their family, appearing superficially more similar to sweat bees. They are generalists, foraging on a wide range of plant species, and nesting in hollows created by boring out the pith of stems such as sumac. Small carpenter bees are “subsocial”, meaning that adults overwinter in their natal nests and females, which can live a year or more, care for their adult offspring throughout the growing season (Rehan and Richards 2010). Ceratina calcarata is of special interest in the evolution of sociality in bees, as this species exhibits an “incipiently eusocial” stage late in the season, at which time they produce dwarf female young that help care for their late-season siblings while having no chance of reproducing themselves (Rehan et al. 2014). This appears to be accomplished by provision of a smaller and less floristically diverse pollen ball to these brood cells (Lawson et al. 2016). Figure 8. Ceratina dupla, female. Photo: USGS BIML.

Revision of this genus in Eastern North America based on both molecular and morphological data has resulted in the recognition of three closely related species, Ceratina dupla, Ceratina mikmaqi, and Ceratina floridana (Rehan and Sheffield 2011) that can be difficult to identify with certainty. Phylogenetic analysis shows that the five northeastern sympatric species of Ceratina are recently diverged and their speciation may be driven by specialization in ecological niche, in particular related to nest site selection (Shell and Rehan 2016). Table 9. Small Carpenter Bees: Genus Ceratina (4)

Ceratina calcarata

Wide-legged Small Carpenter Bee

184

Ceratina dupla

Common Eastern Small Carpenter Bee

Ceratina mikmaqi

Mikmaq Small Carpenter Bee

Ceratina strenua

White-striped Small Carpenter Bee

Cuckoo Bees (Genus Nomada) The Nomada cuckoo bees are cleptoparasites of miner bees in the genus Andrena. The species in the bidentate group are not well understood taxonomically yet, so they cannot be identified to species at this time. Two specimens were tentatively identified as Nomada species 1, and are being sent for DNA barcoding. Table 10. Cuckoo Bees: Genus Nomada (9) Nomada (bidentate grp.)

Nomada depressa

Depressed Cuckoo Bee

Nomada luteola

Yellow Cuckoo Bee

Nomada luteoloides

Yellowish Cuckoo Bee

Nomada maculata

Spotted Cuckoo Bee

Nomada pygmaea

Pygmy Cuckoo Bee

Nomada sayi / illinoense

Nomada sp. 1

Nomada sulphurata

Sulphury Cuckoo Bee

Figure 9. Nomada aculate, female. Photo: USGS BIML

Long-horned Bees (Genera Eucera, Melissodes) The long-horned bees of the trib Eucerini are characterized by the extremely long, threadlike antennae of the males. A number of these species are oligolectic, many on late summer and fall composites. Eucera hamata is a large and impressive long-horned bee that was very common throughout the study at the Red Clay Reservation wet meadow sampling site. It was numerically one of the most common bee in our survey, with the vast majority of individuals collected at the wet meadow site. Table 11. Long-horned Bees: Genera Eucera, Melissodes (6) Eucera hamata

Hooked Long-horned Bee

185

Melisodes bimaculatus

Two-spotted Long-horned Bee

Melissodes denticulatus

Denticulate Long-horned Bee

Melissodes desponsus

Thistle Long-horned Bee

Melissodes subillatus

Echinacea Long-horned Bee

Melissodes trinodis

Three-knotted Long-horned Bee

Other Apidae (Genera Peponapis, Ptilothrix, Svastra) These three large apid species are all specialists on various plant groups. They were each represented by single specimens in our survey, all from the Red Clay Reservation Wet Meadow. Table 12. Squash, Mallow and Sunflower Bees: Genera Peponapis, Ptilothrix, Svastra (3)

Peponapis pruinosa

Squash Bee

Ptilothrix bombiformis

Mallow Bee

Svastra obliqua

Sunflower Bee

Family Halictidae Furrow Bees (Genus Halictus) The nominate genus of the family, Halictus sweat bees are characterized by primitive eusociality. They are generalists found in a wide variety of open habitats. The common open country bees Halictus ligatus and H. poeyi are cryptic sister species not separable morphologically but characterized by divergence of nuclear (Carman and Packer 1996) and mitochondrial (Danforth et al. 1998) DNA. Packer (1999) found H. ligatus to be the distributed to the north and at higher elevations than H. poeyi, which is a southeastern coastal plain species, but the two species are sympatric at some piedmont sites. Table 13. Furrow Bees: Genus Halictus (3) Halictus confusus

Confusing Metallic Furrow Bee

Halictus ligatus/poeyi

Ligated / Poey’s Furrow Bees

Halictus rubicundus

Orange-legged Furrow Bee

Figure 10. Halictus poeyi, female. Photo: USGS BIML

Metallic Green Bees (Genera Auchlora, Augochorella, Augochloropsis, and Agapostemon) These race car green or blue-green metallic bees are the consummate generalists. They are very common in open habitats such as meadows, edges, and suburban parks. Augochlora pura, one of the top ten most abundant bee in our survey, is a forest species that nests in dead wood. Augochorella aurata, another very abundant species, is a eusocial ground-nester. Table 14. Metallic Green Bees: Genera Augochlora, Augochlorella, Augochloropsis, Agapostemon (5) Agapostemon texanus

Texas Sweat Bee

Agapostemon virescens

Bicolored Striped Sweat Bee

Augochlora pura

Pure Sweat Bee

116

Augochlorella aurata

Golden Sweat Bee

169

Augochloropsis metallica fulgida

Metallic Epauletted Sweat Bee

Figure 11. Augochlora pura, female. Photo: USGS BIML.

Metallic Sweat Bees (Genus Lasioglossum, Subgenus Dialictus) The genus Lasioglossum is one of the largest bee genera in North America, with several distinct subgenera, the largest of which is Dialictus, tiny metallic bees that are very difficult to identify. The subgenus was recently revised by Gibbs (2010, 2011) Among the members of this group found in our survey, Bartomeus et al. (2013) found L. pilosum and L. leucomum to be potentially declining rangewide. This is of concern as L. pilosum was one of the more common Dialictus species found in our work. Lasioglossum cattellae (Ellis 1913) is reported here for the first time from northern Delaware. This species was reported at low numbers in forested habitats by Droege (2013) and Savoy-Burke (2017). It seems to be unusually common at Mt. Cuba. Lasioglossum subviridatum (Cockerell) is a species only uncommonly recorded in the area and is rarely found in fields or open areas. The large numbers documented here indicate that this species may be more common than previously suspected. Unlike most members of the subgenus, some species nest in rotten wood, including Lasioglossum oblongum and L. subviridatum (Gibbs 2011), L. coeruleum (Stockhammer 1967) and L. cressonii (Mitchell 1960). Table 15. Sweat Bees: Genus Lasioglossum (Subgenus Dialictus) (23)

Lasioglossum abanci

A Sweat Bee

Lasioglossum admirandum

Admirable Sweat Bee

Lasioglossum bruneri

Bruner’s Sweat Bee

Lasioglossum callidum

Crafty Sweat Bee

Lasioglossum cattellae

Whelp Sweat Bee

Lasioglossum coeruleum

Deep-Blue Sweat Bee

Lasioglossum cressonii

Cresson’s Sweat Bee

Lasioglossum gotham

Gotham Sweat Bee

Lasioglossu hitchensi

Hitchens’s Sweat Bee

Lasioglossum illinoense

Horseshoe Sweat Bee

Lasioglossu imitatum

Bristle Sweat Bee

Lasioglossum leucomomum

White-haired Golden Sweat Bee

Lasioglossum oblongum

Oblong Sweat Bee

Lasioglossum obscurum

Obscure Sweat Bee

Lasioglossum paradmirandum

Stunning Sweat Bee

Lasioglossum pilosum

Hairy Sweat Bee

Lasioglossum rozeni

Rozen’s Sweat Bee

Lasioglossum smilacinae

Mayflower Sweat Bee

Lasioglossum subviridatum

Western Green Sweat Bee

Lasioglossum tegulare

White-shouldered Sweat Bee

Lasioglossum trigeminum

Trigeminal Sweat Bee

Lasioglossum versatum

Experienced Sweat Bee

Lasioglossum weemsi

Weems’s Sweat Bee

Sweat Bees (Genus Lasioglossum, Other Subgenera) Our study documented one species each of four of the other subegenera of Lasioglossum. Lasioglossum quebecense (Crawford) was overall the most abundant species of Lasioglossum captured, consistent with other studies of bottomland and riparian forests (Droege 2013), which it seems to favor. Table 16. Sweat Bees: Genus Lasioglossum (Other Subgenera) (4) Lasioglossum (Hemihalictus) foxii

Fox’s Sweat Bee

Lasioglossum (Lasioglossum) fuscipenne

Dark-winged Sweat Bee

Lasioglossum (Leuhalictus) leucozonium

White-banded Sweat Bee

Lasioglossum (Sphecodogastra) quebecense

Quebec Sweat Bee

215

Blood Bees (Genus Sphecodes) This is a poorly-known genus of cleptoparasite or social parasite bees in which accurate species identifications are difficult, hence the “near” designation in the material below. Sphecodes pimpinellae is a nest parasite of the common metallic sweat bee Augochlorella aurata, the latter being one of the most common bees in our survey (Ordway 1964). Table 17. Blood Bees: Genus Sphecodes (3)

Sphecodes nr. pimpinellae

Sphecodes aroniae

Sphecodes nr. coronus

Andrenidae Miner Bees (Genera Andrena and Pseudopanurgus) The miner bees in the genus Andrena are one of the largest genera of native bees, with over 1,300 species worldwide. They are among the most common of spring bees in the forest, but there are also many uncommon to rare species that specialize on certain groups of plants. Significant finds during this survey were new state records for Delaware for seven speies, including Andrena cornelli, A. dunningi, A. nigrae, A. platyparia, A. polemonii, A. rehni, and A. uvulariae. An unknown species, Andrena sp. 1, will be sent for DNA barcoding. Table 18. Miner Bees: Genera Andrena, Pseudopanurgus (36) Andrena arabis

Mustard Miner Bee

Andrena banksi

Banks’s Miner Bee

Andrena barbara

Barbara’s Miner

Andrena carlini

Carlinville Miner Bee

257

Andrena cornelli

Azalea Miner Bee

Andrena cressonii

Yellow-legged Miner Bee

Andrena dunningi

Dunning’s Miner Bee

Andrena erigeniae

Spring Beauty Miner Bee

124

Andrena forbesii

Forbes’s Miner Bee

Andrena fragilis

Fragile Miner Bee

Andrena heraclei

Parsnip Miner Bee

Andrena hippotes

Hippotes Miner Bee

Andrena illini

Illini Miner Bee

Andrena imitatrix/morrisonella

Andrena macoupinensis

Macoupin County Miner Bee

Andrena miserabilis

Smooth-faced Miner Bee

Andrena nasonii

Bumped Miner Bee

Andrena nigrae

Black Willow Miner Bee

Andrena nubecula

Cloudy-winged Miner Bee

Andrena nuda

Naked Miner Bee

Andrena perplexa

Confusd Miner Bee

Andrena personata

Masked Miner Bee

Andrena platyparia

Plated Miner Bee

Andrena polemonii

Jacob’s Ladder Miner Bee

Andrena pruni

Cherry Miner Bee

Andrena rehni

Rehn’s Miner Bee

Andrena robertsonii

Robertson’s Miner Bee

Andrena rugosa

Wrinkled Miner Bee

Andrena spiraeana

Goatsbeard Miner Bee

Andrena tridens

Trident Miner Bee

Andrena uvulariae

Bellwort Miner Bee

Andrena vicina

Neighbor Miner Bee

Andrena violae

Violet Miner Bee

144

Andrena wilkella

European Legume Miner Bee

Andrena sp. 1 Pseudopanurgus compositarum

4 Composite Miner Bee

Figure 12. Images of our specimens of Andrena polemonii, representing a major range extension of this species, previously known from the Ohio Valley in West Virginia. Photo: USGS BIML.

Family Megachilidae Mason Bees (Genus Osmia) The mason bees are an early spring genus of stem nesters. Often, the non-native species Osmia cornifrons and Osmia taurus dominate spring pan trap collections. In fact, long-term declines of native mason bees have been documented in association with increases in their non-native congeners (LeCroy et al. 2020). In our case, they did not, with the native Osmia pumila being the dominant species in terms of abundance. All species except for O. distincta were found in both the gardens and the floodplain of the Red Clay Creek. Osmia distincta – We specifically targeted this beardtongue specialist on its host genus Penstemon. We succeeded in collecting it on Penstemon digitalis “Husker Red”, as well as P. canescens and P. calycosus. The closest exsiting record to Delmarva is from Cecil County, MD. Table 19. Mason Bees: Genus Osmia (7) Osmia atriventris

Maine Blueberry Bee

Osmia bucephala

Bufflehead Mason Bee

Osmia collinsiae

Collins’s Mason Bee

Osmia cornifrons

Hornfaced Bee

Osmia distincta

Distinct Mason Bee

Osmia georgica

Georgia Mason Bee

Osmia pumila

Dwarf Mason Bee

Osmia taurus

Taurus Mason Bee

Resin Bees and Others (Genera Chelostoma, Heriades, Hoplitis) Our study documented small numbers of five additional species belonging to other genera in the tribe Osmiini. Chelostoma and Hoplitis pilosifrons are fairly uncommonly collected. Table 20. Resin Bees and Others: Genera Chelostoma, Heriades, Hoplitis (5)

Chelostoma philadelphi

Mock-orange Skinny Mason Bee

Heriades carinata

Carinate Sculptured Mason Bee

Heriades leavitti / variolosa

A Sculptured Mason Bee

Hoplitis pilosifrons

Hairy-faced Summer Mason Bee

Hoplitis producta

Prolonged Summer Mason Bee

Leaf-cutter Bees and Cuckoo Leaf-cutter Bees: Genera Megachile and Coelioxys Leaf-cutter bees, genus Megachile, were somewhat underrepresented in our sampling, probably due to the fact that they are often open country bees that utilize summer and fall composites and other species of early successional habitats, while our sampling focused heavily on forested areas and vernal flora. Nevertheless, further survey of late summer and early fall flora in both the gardens and the natural areas should discover additional species. Our specimen of Megachile gemula, collected on Hydrophyllum, is Delaware’s 2nd state record, and the first since 1961, when a single specimen was collected near Dragon Run and the Delaware City Refinery. That specimen is now in the Cornell University Insect Collection (CUIC_ENT00025162). .

Table 21. Leacutter Bees and Cuckoo Leaf-cutter Bees: Genera Megachile, Coelioxys (7) Coelioxys sayi

Say’s Cuckoo Leaf-cutter Bee

Megachile frugalis

Virtuous Leaf-cutter Bee

Megachile gemula

Small-handed Leaf-cutter Bee

Megachile inimica

Hostile Leaf-cutter Bee

Megachile mendica

Beggar Leaf-cutter Bee

Megachile mucida

Moldy Leaf-cutter Bee

Megachile xylocopoides

Carpenter-mimc Leaf-cutter Bee

Woolcarder Bees (Genus Anthidium) Anthidium, the woolcarder bees, are represented here by two widespread, introduced European species, Anthidium manicatum and Anthidium oblongatum. The European Woolcarder was introduced prior to 1963, but the Oblong Woolcarder was a more recent introduction in the 1990s. They are so named because the adults gather leaf hairs from woolly or downy species that they use to line their nest cells. Both species tend to favor plants in the legume family. Table 22. Woolcarder Bees: Genus Anthidium (2)

Anthidium manicatum

European Woolcarder

Anthidium oblongatum

Oblong Woolcarder

Selected Plants and Important Bee Associations at Mt. Cuba Woody Plants Castanea (Chestnuts) The hybrid chestnut grove established at the Red Clay Reservation yielded specimens of 8 bee species during sampling of lower branches of two of the larger trees. Among these were several specimens of the Castanea pollen specialist Andrena rehni, representing a new record for Delaware. This species would have been much more common when American chestnut dominated eastern forests prior to its decline from chestnut blight. It appears that its bee associates have been able to persist in the region by utilizing chinkapin (Castanea pumila) and perhaps the occasional resistant C. dentata. Mount Cuba can play a role in helping to conserve Andrena rehni (and possibly other species that historically relied on Castanea) by continuing to participate in chestnut research and propagation and by including Castanea pumila in the gardens and as part of restorations.

Cercis (Redbud) The beautiful pea-like blossoms of the eastern redbud, Cercis canadensis, are highly attractive to numerous species of spring bees, making them a key woody species in the bee-friendly landscape. We documented nine species of bees using this species at Mt. Cuba, but did not find the specialist Habropoda laboriosa.

Cornus (Swida) (Shrub Dogwoods) The shrub dogwoods of the subgenus Swida are very attractive to native bees. Our survey documented the miner bees Andrena fragilis, A. perplexa, and A. platyparia. Andrena platyparia, the plated miner bee, and Andrena fragilis, the fragile miner bee, are both pollen specialists on this group of dogwoods. A. platyparia is rare or at least undercollected in the area and our two specimens, from Cornus amomum, represent a new state record for Delaware. We found this shrubby Cornus in bloom only at the Red Clay Reservation Wet Meadow, and we strongly recommend increased plantings of this and other native species of shrubby Cornus (Swida) in the natural areas and perhaps the garden where appropriate.

Hydrangea (Hydrangeas) Hydrangeas are incredibly attractive to bumble bees, and H. radiata appears to be one of the best species. We collected ten species of bees visiting H. radiata including abundant bumble bees of 4 different species. Lace-cap native Hydrangeas such as H. radiata and H. arborescens are an important resource for a wide variety of large and small bees.

Rhododendron (Azaleas & Rhododendrons) Rhododendron species are important in the shrub layer of the gardens at Mt. Cuba and they represent a significant resource for native bees. While the large flowers of some North American azalea species (section Pentanthera) with their long, exserted pistils and stamens are apparently efficiently pollinated only by wing contact of large swallowtail butterflies (Epps et al. 2015), these species are also visited by native bees, predominately miner bees. Our survey documented Delaware’s first records of Andrena cornelli, a specialist on Rhododendron. This species is unusual in

Figure 13. A male miner bee (Andrena nasonii) apparently attempting to nectar on Rhododendron periclymenoides. Photo: Sarver Ecological

having the scopal hairs of its pollen brush very widely spaced in order to accommodate the large pollen of its favored host. We netted both females and males at Rhododendron vaseyi and Rhododendron periclymenoides in the garden on 7 May 2018. Interestingly, Epps et al. (2015) found that while Andrena cornelli was a common pollen feeder at R. calendulaceum in their study, it was not an effective pollinator. The evergreen rhododendrons including R. maximum seem to attract a high visitation rate of bumblebees, especially queens, but relatively few smaller native bees.

Rubus (Blackberries and Raspberries) While brambles in the genus Rubus are not typically considered ornamental species, the large, showy white flowers are highly attractive to a wide variety of native bee species. We found nine species visiting Rubus allegheniensis, based upon only 11 collected individuals. This species, as well as R. occidentalis should be included in restoration plant palettes.

Salix (Willows) Salix is arguably the most important genus for bee diversity in the eastern U.S. The genus supports an astonishing diversity of native bees, including some 14 specialist species in the eastern U.S. (See Appendix A). In fact, recent work by Mosseler et al. (2020) suggests that willows may be planted to enhance the pollination of crop species while minimizing the need for costly importation of non-native honeybees. We documented 17 species on black willow (Salix nigra), including the willow specialists Andrena macoupinensis and Andrena nigrae, the latter representing a new state record for Delaware. Simon et al. (2020, Preprint) found that A. nigrae was the only floral visitor to black willow that occurred more frequently on female flowers, though we also found them numerous on the male catkins we sampled. We observed black willow in small numbers at the Red Clay Reservation Wet Meadow as well as along ditches at the corner of Barley Mill Rd. and the railroad right-of-way. It has been included in reforestation plantings in the Floodplain area although those plantings appear to be composed of nearly all female trees, and cold probably benefit from the addition of a few more males. We recommend increasing the use of Salix species in restoration throughout the natural areas in appropriate sites. The ornamental pussy willow (Salix discolor) and perhaps other species of shrub willow could be incorporated into the gardens to provide additional resources for specialist bees.

Figure 14. A male miner bee (Andrena sp.) foraging on a male catkin of Black Willow (Salix nigra) at Mt. Cuba, along Barley Mill Road near the Red Clay Creek.

Perennial Forbs Cardamine (Toothwort) Spend a few minutes watching the snowy clusters of toothwort flowers, and you will surely see multiple native bees. This species is popular with early spring miner bees, and we documented eight bee species using C. concatenata and C. diphylla in the gardens, including the rare Andrena uvulariae and Andrena polemonii, specialists on the pollen of bellwort and Jacob’s ladder, respectively. These species were likely visiting for nectar. Cardamine and the related mustard genus Boechera (formerly Arabis, the rock cresses) host a specialized pollen feeder, Andrena arabis, which we documented from one specimen in a bowl trap at the Floodplain site, but which we did not find in the gardens. Further sampling on these genera may ascertain whether A. arabis is also present in the gardens. Increasing the amount of Cardamine and perhaps planting Arabis canadensis, which is a Delaware rare species (S2), might enhance habitat for Andrena arabis. Continuation of the ongoing restoration work along the Red Clay floodplain to reduce the cover of invasive Ficaria verna and promote native ephemerals like Cardamine will also benefit this bee.

Cirsium (Thistles) Thistle are superb bee and butterfly plants, if a little nontraditional as ornamentals. We sampled both Cirsium horridulum in the Meadow Garden and a population of Cirsium discolor in the Red Clay Reservation natural areas that has been promoted and managed for by Nathan Shampine and his staff. C. horridulum yielded the study’s only record of the striking black leafcutter bee Megachile xylocopoides, a species reaching the limit of its distribution here, as well as the long-horned bee Melissodes subillatus, and the first Delaware state records of Megachile frugalis, a leaf-cutter bee associated with native legumes and composites. M. frugalis is a species typical of higher quality natural areas and a good indicator of the importance of the Meadow Garden in providing that type of setting, despite its artificial origins. Our Cirsium discolor samples yielded the study’s only Melissodes desponsus, an Asteraceae pollen specialist with a predeliction for Cirsium, as well as our only Heriades leavitti / variolosa (a male that could not readily be identified to species). We also observed high diversity and abundance of native Lepidoptera using both species of thistle. We recommend maintaining existing Cirsium populations and using native thistle species heavily in restoration.

Claytonia (Spring Beauty) While it does not host a high diversity of bees, this diminuitive spring ephemeral is the host plant for the common and charismatic little miner bee Andrena erigeniae, one of the top ten most common bees in our surveys. It is also frequently visited by bee flies. Claytonia should be encouraged and invasive species that outcompete it should be controlled in natural areas.

Eurybia (Wood Asters) A somewhat overlooked genus in pollinator studies, the wood asters are excellent for late summer bees. A total of 17 species visited Eurybia in our study, which sampled from all three species found at Mt. Cuba. While it is often thought to prefer goldenrods, two of our three specimens of the Asteraceae specialist Andrena nubecula, the Cloudy-winged Miner Bee were from Eurybia.

Helianthus (Sunflowers) Native sunflowers are one of the most important of North American genera for native bee diversity, especially specialist bees (see Appendix A). However, the Helianthus species diversity and abundance at Mt Cuba is low, so we were unable to document any of the associated pollen specialists. We encourage the planting of a number of native species of the genus including H. divaricatus and H. decapetalus, both appropriate species for the Northern Piedmont ecoregion.

Heuchera (Alumroot) As described earlier in this report, Heuchera is a highly significant genus at Mt. Cuba due to its hosting of the rarest bee of our study, the Summer Cellophane Bee, Colletes aestivalis, documented here for the first time in decades in the northeastern US. Notably, despite the nearby presence of several Heuchera cultivars, we only observed C. aestivalis visiting and defending the straight species of Heuchera americana. Stephen (1954) reported it to be oligolectic on H. americana and “Heuchera hispida”, a taxon with a long

history of confusion, as explained by Wells and Shipes (2009): “Heuchera hispida (H. americana var. hispida here…) was confused with H. richardsonii for almost a hundred years, until C. O. Rosendahl et al. (1933) pointed out that the plants from the Midwest then passing as H. hispida Pursh were distinct from Pursh’s species and were H. richardsonii.” Unless further observations dictate otherwise, we recommend assuming the species will use both Heuchera americana and Heuchera richardsonii, but not other species or cultivars. Immediate increases in the amount of Heuchera americana in the gardens should be considered to help conserve this rare bee, and we encourage Mt. Cuba to explore propagation of this species for restoration in the natural areas where appropriate and to promote straight species Heuchera americana in the nursery trade, where it is currently very difficult to obtain consistently.

Hydrophyllum (Waterleaf) The white flower clusters of Virginia waterleaf are highly attractive to early spring bees. We documented eight species of spring flying bees attending this plant, but not the uncommon (and misnamed) pollen specialist Andrena geranii. Additional emphasis on Hydrophyllum in the gardens and planting in natural areas would be appropriate.

Mertensia (Bluebells) The floodplains of Piedmont streams in our region become wonderlands of Virginia Bluebells in early spring. This species has been planted extensively in the Mt Cuba gardens as well. It is a superb bee plant for long-tongued bees, especially bumble bees, in early spring. We documented 12 species using Mertensia and it is highly favored by Bombus queens in early spring.

Packera (Golden Ragwort) For such a deer-resistant, easy to grow species, Packera aurea has an excellent list of insect associates, including bees. It attracts numerous miner bees and their parasites, the Nomada species. We documented 11 species using it, but could not find Andrena gardineri, the pollen specialist known from the mountains in adjacent states. This species should be used in all appropriate garden and natural areas settings.

Penstemon (Beardtongues) Our sampling on Penstemon in this study documented use by 11 species of bee visitors. Consistent with the findings of Dieringer and Cabrera (2002) in Illinois, Ceratina calcarata and Hoplitis pilosifrons were among the primary small bee visitors of P. digitalis. We also documented use by the sweat bee Lasioglossum versatum. Penstemon species were visited by several bumblebee species, including some of the only Bombus fervidus workers of our study, as well as the common B. impatiens and B. bimaculatus. Interestingly, while the long-horned bee Eucera hamata was common in pan traps at the Red Clay Wet Meadow our only floral visitor observations of this species were on P. digitalis. We found Delaware’s first state record of the beardtongue specialist mason bee Osmia distincta visiting three different species at Mt. Cuba: Penstemon digitalis ‘Husker Red’, Penstemon calycosus, and Penstemon canescens. Penstemons are excellent mid-summer plants for long-tongues bees and should be maximized in both ornamental and natural settings.

Figure 15. Osmia distincta, a Beartongue specialist. Photo: Thomas Wood

Phacelia (Scorpionweed) Two species, Phacelia bipinnatifida and Phacelia purshii are present in the gardens, and both are highly attractive to a variety of bees. While these species should probably not be planted in the natural areas due to the fact that they are not native to Delaware, they are included here as notable bee plants from our survey of the gardens.

Polemonium (Jacob’s Ladder) Jacob’s Ladder (Polemonium reptans) is a dominant herbaceous species in the forested areas of the garden, and there are remnant populations along the Floodplain area of the Red Clay, though it seems to have suffered from deer browse and invasive species

competition there. We documented five species of bees using Polemonium, a number that would likely have increased with more sampling, as the open floral shape is accessible to many species. A major highlight of the project was the find of the Jacob’s Ladder Miner Bee, Andrena polemonii some 365 miles from the nearest known population in the Ohio River drainage of West Virginia.

Rudbeckia (Black-eyed Susans and Others) Rudbeckias are important bee species with an uncommon pollen specialist (Andrena rudbeckiae) known from our area. We were not able to find this species during the survey but it is likely present. Rudbeckia laciniata seems to be the best of the genus for bee abundance and diversity, followed distantly by Rudbeckia fulgida, with Rudbeckia hirta seemingly much less attractive than either of the former. We recommend increasing the abundance of Rudbeckia laciniata in both the gardens and the natural areas.

Solidago and Euthamia (Goldenrods) Goldenrods are important species for late fall specialists and for supporting generalist species like bumble bees late in the season. Our observations indicate that Euthamia graminifolia may be among the best species in this group for bee abundance and diversity. We collected 101 bees of at least 16 species using Euthamia, and 64 bees of 13 species using all other Solidago species. Goldenrods should be a staple for any meadow garden or restoration, and Euthamia graminifolia should be included whenever possible.

Symphyotrichum (Asters) Figure 16. Andrena nubecula, an Asteraceae specialist, was found on Solidago sphacelata, Eurybia Asters are highly important for bees in late macrophylla, and E. divaricata in the Meadow Garden. Photo: Nicholas Dorian summer and early fall. Symphyotrichum pilosum hosted a diverse assemblage of bee visitors (11 species) and historically has been known as one of the best of the composites for native bees.

Uvularia (Bellworts) Mt. Cuba has a superb collection of this genus, particularly Uvularia grandiflora, in the gardens and thus hosts the rare specialist Andrena uvulariae. In addition, many other species of bees, from large Bombus species to small Nomada have been found climbin up into the pendulous, bell-like flowers. We encourage continued emphasis on this group in the garden and appropriate conservation efforts for any sites where it is found in the natural areas.

Veronicastrum (Culver’s Root) While it lacks any specialist bees, Culver’s Root is frequently abuzz with tiny Lasioglossum sweat bees, as well as bumble bees and mining bees. We found eleven species using it during this study. The species is historical in the Delaware Piedmont, and it may be possible to work with the state botanist to reintroduce it to likely habitats, such as wet meadow.

Vernonia (Ironweed) The common ironweed in our area is Vernonia noveboracensis, New York ironweed, a dominant forb in the Red Clay Reservation wet meadow, where our sampling on it took place. It hosts large numbers of long-horned bees, including the Asteraceae specialists Melissodes denticulatus, M. trinodis, and Svastra obliqua. We collected all three of these species on ironweed in the Red Clay meadow. We

recommend it as a key component of restorations in early successional habiat, and encourage further use of V. noveboracensis in the gardens.

Viola (Violets) The lowly violet is a native bee powerhouse, hosting the common specialist Andrena violae, with its striking yellow eyebrows (facial fovea) as well as several other small spring bees and hoverflies. We sampled only from Viola striata, and found that it was being used by Andrena polemonii (presumably for nectar) plus at least a half a dozen other bee species. All violets, including the common lawn “weeds” Viola sororia, should be encouraged for their native bee value.

Zizia (Golden Alexanders) Zizia aurea in the Meadow Garden was consistently one of the most active plant species of late spring through early summer for small bees. The dominant visitors were generalist miner bees including Andrena robertsonii, A. cressonii, and male Trachandrena of undetermined species (La Berge 1973 notes Zizia as among the plants used by a few of our local Trachandrena, including A. forbesii and A. hippotes). This easy to propagate species should be used extensively in both gardens and natural areas (it is rare in Delaware so restoration should probably be in consultation with the state botanist).

Figure 17. A Melissodes Long-horned bee on Vernonia.

Literature Cited Ascher, J. S. and J. Pickering. 2020. Discover Life bee species guide and world checklist (Hymenoptera: Apoidea: Anthophila). http://www.discoverlife.org/mp/20q?guide=Apoidea_species Bartomeus, I., J.S. Ascher, J. Gibbs, B.N. Danforth, D.L. Wagner, D.L. Hetdke, and R. Winfree. 2013. Historical changes in northeastern US bee pollinators related to shared ecological traits. Proceedings of the National Academy of Sciences 110:4656–4660. Cameron, S.A., J.D. Lozier, J.P. Strange, J.B. Koch, N. Cordes, and L.F. Solter. 2011. Patterns of widespread decline in North American bumble bees. Proceedings of the National Society of Sciences 108:662–667. Carman, G. M., & Packer, L. (1996). A cryptic species allied to Halictus ligatus Say (Hymenoptera: Halictidae) detected by allozyme electrophoresis. Journal of the Kansas Entomological Society, 168-176. Chao, A., Gotelli, N. J., Hsieh, T. C., Sander, E. L., Ma, K. H., Colwell, R. K., & Ellison, A. M. (2014). Rarefaction and extrapolation with Hill numbers: a framework for sampling and estimation in species diversity studies. Ecological Monographs, 84(1), 45–67. doi:10.1890/13-0133.1 Chao, A., Ma, K. H., and Hsieh, T. C. (2016) iNEXT (iNterpolation and EXTrapolation) Online. Program and User's Guide published at http://chao.stat.nthu.edu.tw/wordpress/software_download/ Chao, A., & Jost, L. (2015). Estimating diversity and entropy profiles via discovery rates of new species. Methods in Ecology and Evolution, 6(8), 873-882. Colla, S., and L. Packer. 2008. Evidence for decline in eastern North American bumblebees (Hymenoptera: Apidae), with special focus on Bombus affinis Cresson. Biodiversity Conservation 17:1379–1391. Danforth, B. N., Mitchell, P. L., & Packer, L. (1998). Mitochondrial DNA differentiation between two cryptic Halictus (Hymenoptera: Halictidae) species. Annals of the Entomological Society of America, 91(4), 387-391. Danforth, B. N., Minckley, R. L., Neff, J. L., & Fawcett, F. (2019). The Solitary Bees: Biology, Evolution, Conservation. Princeton University Press. Delaware Department of Natural Resources and Environmental Control (DNREC). 2015. 2015-2025 Delaware Wildlife Action Plan. Dover, Delaware, USA. Donovall, III, L.R. and D. vanEngelsdorp. 2010. A checklist of the bees (Hymenoptera: Apoidea) of Pennsylvania. Journal of the Kansas Entomological Society. 83(1): 7-24. Droege, S.W. 2013. Investigation of the Spring Bee Fauna (Hymenoptera: Apoidea) of Seven Woodland Sites in the Coastal Plain of Maryland using Continuously-trapping Arrays of Propylene Glycol Cup Traps. The Maryland Entomologist 6(1): 43-55. Epps, M. J., Allison, S. E., & Wolfe, L. M. (2015). Reproduction in flame azalea (Rhododendron calendulaceum, Ericaceae): a rare case of insect wing pollination. The American Naturalist, 186(2), 294-301. Fowler, J. 2016. Specialist bees of the Mid-Atlantic: Host plants and habitat conservation. The Maryland Entomologist. 6(4): 2-40. Fowler, J. 2016. Specialist bees of the Northeast: Host plants and habitat conservation. Northeastern Naturalist. 23(2): 305-320. Gibbs, J. 2010. Revision of the metallic species of Lasioglossum (Dialictus) in Canada (Hymenoptera, Halictidae, Halictini). Zootaxa 2591:1–382. Gibbs, J. 2011. Revision of the metallic species of Lasioglossum (Dialictus) of eastern North America (Hymenoptera, Halictidae, Halictini). Zootaxa 3073:1–216.

Gibbs, J., Ascher, J. S., Rightmyer, M. G., & Isaacs, R. (2017). The bees of Michigan (Hymenoptera: Apoidea: Anthophila), with notes on distribution, taxonomy, pollination, and natural history. Zootaxa, 4352(1), 1-160. Gibbs, J., N.K. Joshi, J.K. Wilson, N.L. Rothwell, K. Powers, M. Haas, L. Gut, D.J. Bid-dinger, and R. Isaacs. 2017. Does passive sampling accurately reflect the bee (Apoidea: Anthophila) communities pollinating Apple and Sour Cherry orchards? Environmental Entomology 89:138–157 Giles, V., and J.S. Ascher. 2006. A survey of the bees of the Black Rock Forest Preserve, New York (Hymenoptera: Apoidea). Journal of Hymenoptera Research 15:208–231. Gotelli, N. J., & Colwell, R. K. (2001). Quantifying biodiversity: procedures and pitfalls in the measurement and comparison of species richness. Ecology letters, 4(4), 379-391. Gotelli, N. J., & Colwell, R. K. (2011). Estimating species richness. Biological diversity: frontiers in measurement and assessment, 12, 39-54. Hurd, P.D. 1979. Superfamily Apoidea. Pp. 1741–2209, In K.V. Krombein, P.D. Hurd Jr., D.R. Smith, and B.D. Burks (Eds.). Catalog of Hymenoptera in America North of Mexico. Volume II. Smithsonian Institution Press, Washington, DC. 2145 pp. LeCroy, K. A., Savoy-Burke, G., Carr, D. E., Delaney, D. A., & Roulston, T.H. (2020). Decline of six native mason bee species following the arrival of an exotic congener. Scientific reports, 10(1), 1-9. LeBuhn, G., T. Griswold, R. Minckley, S. Droege, T. Roulston, J. Cane, F. Parker, S. Bu- chmann, V. Tepedino, N. Williams, C. Kremen, and O. Messenger. 2003. A standardized method for monitoring bee populations—the bee inventory (BI) plot. Available online at http://online.sfsu.edu/beeplot/pdfs/Bee%20Plot%202003.pdf. Accessed 1 February 2017. Berge, W. E. L. (1973). A revision of the bees of the genus Andrena of the Western Hemisphere. Part VI. Subgenus Trachandrena. Transactions of the American Entomological Society (1890-), 99(3), 235-371. Lawson, S. P., Ciaccio, K. N., & Rehan, S. M. (2016). Maternal manipulation of pollen provisions affects worker production in a small carpenter bee. Behavioral ecology and sociobiology, 70(11), 1891-1900. Minckley RL, Roulston TH, Williams NM. 2013. Resource assurance predicts specialist and generalist bee activity in drought. Proc R Soc B Biol Sci. 280. Mitchell, TB. 1960. Bees of the Eastern United States. Vol. I. North Carolina Agricultural Experiment Station Technical Bulletin No. 141. Mitchell, TB. 1962. Bees of the Eastern United States. Vol. II. North Carolina Agricultural Experiment Station Technical Bulletin No. 152. Mosseler, A., Major, J., Ostaff, D., & Ascher, J. (2020). Bee foraging preferences on three willow (Salix) species: Effects of species, plant sex, sampling day and time of day. Annals of Applied Biology, 177(3), 333-345. Ordway, E. (1964). Sphecodes pimpinellae and other enemies of Augochlorella (Hymenoptera: Halictidae). Journal of the Kansas Entomological Society, 37(2), 139-152. Packer, L. (1999) The distribution of Halictus ligatus Say and H. poeyi Lep. (Hymenoptera; Halictidae) in North America. In: Byers, G.W.R., Hagen, R.H., & Brooks, R.W. (Eds.), Entomological Contributions in Memory of Byron A. Alexander. University of Kansas Natural History Museum Special Publication, 24, pp. 81–84. Parker, A. J., Williams, N. M., & Thomson, J. D. (2016). Specialist pollinators deplete pollen in the spring ephemeral wildflower Claytonia virginica. Ecology and evolution, 6(15), 5169-5177. Rehan, S. M., & Richards, M. H. (2010). Nesting biology and subsociality in Ceratina calcarata (Hymenoptera: Apidae). The Canadian Entomologist, 142(1), 65-74.

Rehan, S.M., & Sheffield, C. 2011. Morphological and molecular delineation of a new species in the Ceratina dupla species-group (Hymenoptera: Apidae: Xylocopinae) of eastern North America. Zootaxa 2873: 35–50. Rehan, S. M., Berens, A. J., & Toth, A. L. (2014). At the brink of eusociality: transcriptomic correlates of worker behaviour in a small carpenter bee. BMC evolutionary biology, 14(1), 260. Satyshur, C. D., & Orr, M. C. (2020). Record of Anthophora (Clisodon) terminalis in a wooden trap-nesting block and comparison to available nesting information (Hymenoptera: Apidae). Journal of Melittology, (99), 1-6. Savoy-Burke, G. (2017). Woodland bee diversity in the Mid-Atlantic (Doctoral dissertation, University of Delaware). Scarpulla, E.J. 2013. A Yearlong Survey of the Bees (Hymenoptera: Apoidea) of a Human-made Habitat Created from Dredged Material: Hart-Miller Island, Chesapeake Bay, Baltimore County, Maryland. The Maryland Entomologist 6(1) 56-84. Shapiro, L. H., Tepedino, V. J., & Minckley, R. L. (2014). Bowling for bees: optimal sample number for “bee bowl” sampling transects. Journal of Insect Conservation, 18(6), 1105-1113. Shell, W. A., & Rehan, S. M. (2016). Recent and rapid diversification of the small carpenter bees in eastern North America. Biological Journal of the Linnean Society, 117(3), 633-645. Simon, S. J., Keefover-Ring, K., Park, Y., Wimp, G., Grady, J, & DiFazio, S.P. 2020. Characterization of Salix nigra floral insect community and activity of three native Andrena bees. bioRxiv 2020.03.23.004309 [Preprint]. [Cited 1 Dec 2020] doi: https://doi.org/10.1101/2020.03.23.004309 Stephen, W. P. 1954. A revision of the bee genus Colletes in America North of Mexico (Hymenoptera, Colletidae). The University of Kansas Science Bulletin 36(1): 149-527. Stockhammer, K. A. (1967). Some notes on the biology of the blue sweat bee, Lasioglossum coeruleum (Apoidea: Halictidae). Journal of the Kansas Entomological Society, 177-189. Williams, N. M., R. L. Minckley, and F. A. Silveira. 2001. Variation in native bee faunas and its implications for detecting community changes. Conservation Ecology 5(1): 7. [online] URL: http://www.consecol.org/vol5/iss1/art7/ Winfree, R., Griswold, T., & Kremen, C. (2007). Effect of human disturbance on bee communities in a forested ecosystem. Conservation biology, 21(1), 213-223.

Appendix A. Mid-Atlantic Specialist Bees and their Host Associations Data from Fowler (2016). Green = documented species (23), Blue = searched for species, still possible to find.

Host Plant Family

Host Plant Genus

Bee Family

Bee Genus (Subgenus) species

Recorded States

Peak Activity

Status

Apiaceae

Zizia

Andrenidae

Andrena (Micrandrena) ziziae

CT-MA-MD-NH-NJ-NY-PAVA-VT-WV

Spring

CommonUncommon

Aquifoliaceae

Ilex

Colletidae

Colletes banksi

CT-NJ-NY-VA

Summer

Rare

Aquifoliaceae

Ilex

Colletidae

Colletes brimleyi

Spring

Rare

Asteraceae

Andrenidae

Andrena (Callandrena) duplicata

CT-NJ-NY

Fall

Rare

Asteraceae

Andrenidae

Andrena (Cnemidandrena) chromotricha

NY-PA-WV

Fall

Rare

Asteraceae

Andrenidae

Perdita (Cockerellia) bequaerti

MD-NJ-NY

Summer

Rare

Asteraceae

Andrenidae

Perdita (Perdita) consobrina

Fall

Rare

Asteraceae

Andrenidae

Perdita (Perdita) swenki

NJ-NY

Summer

Rare

Asteraceae

Andrenidae

Pseudopanurgus albitarsis

Summer

Rare

Asteraceae

Andrenidae

Pseudopanurgus andrenoides

CT-MA-ME-NH-NJ-NY-VAWV

Fall

Uncommon

Asteraceae

Andrenidae

Pseudopanurgus compositarum

CT-DE-MD-NJ-NY-PA-VA-WV

Fall

Uncommon

Asteraceae

Andrenidae

Pseudopanurgus illinoiensis

MD-VA

Spring

Rare

Present at Mt. Cuba

Host Plant Family

Host Plant Genus

Bee Family

Bee Genus (Subgenus) species

Asteraceae

Andrenidae

Asteraceae

Present at Mt. Cuba

Recorded States

Peak Activity

Status

Pseudopanurgus labrosiformis

MD-VA-WV

Summer

Rare

Andrenidae

Pseudopanurgus labrosus

CT-VA-WV

Summer

Uncommon

Asteraceae

Andrenidae

Pseudopanurgus rugosus

MD-VA

Summer

Rare

Asteraceae

Andrenidae

Pseudopanurgus solidaginis

Summer

Uncommon

Asteraceae

Apidae

Melissodes (Eumelissodes) boltoniae

DE-MD-NY-PA-VA

Fall

Uncommon

Asteraceae

Apidae

Melissodes (Eumelissodes) dentiventris

CT-DE-MA-MD-NJ-NY-PA-VA

Fall

Uncommon

Asteraceae

Apidae

Melissodes (Eumelissodes) druriellus

CT-MA-MD-ME-NH-NJ-NYPA-RI-VA-VT-WV

Fall

Uncommon

Asteraceae

Apidae

Melissodes (Eumelissodes) fumosus

MD-VA

Fall

Rare

Asteraceae

Apidae

Melissodes (Eumelissodes) illatus

ME-NY-WV

Fall

Uncommon

Asteraceae

Apidae

Melissodes (Eumelissodes) niveus

MD-NJ-NY-VA

Fall

Uncommon

Asteraceae

Apidae

Melissodes (Eumelissodes) subillatus

CT-DE-MA-MD-ME-NJ-NYPA-VA-WV

Fall

Uncommon

Asteraceae

Apidae

Melissodes (Eumelissodes) trinodis

CT-DE-MA-MD-ME-NJ-NY-RIVA-VT

Fall

Uncommon

Asteraceae

Apidae

Svastra (Epimelissodes) obliqua

DE-MD-NJ-NY-VA

Summer

Uncommon

Asteraceae

Apidae

Svastra (Epimelissodes) petulca

Summer

Rare

Host Plant Family

Host Plant Genus

Bee Family

Bee Genus (Subgenus) species

Asteraceae

Colletidae

Asteraceae

Present at Mt. Cuba

Recorded States

Peak Activity

Status

Colletes compactus

CT-DE-MA-MD-ME-NH-NJNY-PA-RI-VA-VT-WV

Fall

Common

Colletidae

Colletes speculiferus

CT-DE-MA-MD-NJ-NY-RI-VA

Fall

Uncommon

Asteraceae

Colletidae

Colletes thysanellae

Fall

Rare

Asteraceae

Halictidae

Dieunomia (Epinomia) nevadensis

Summer

Rare

Asteraceae

Megachilidae

Dianthidium (Dianthidium) simile

CT-MA-ME-NJ-NY

Fall

Rare

Asteraceae

Megachilidae

Megachile (Argyropile) parallela

Summer

Rare

Asteraceae

Megachilidae

Megachile (Melanosarus) xylocopoides

DE-MD-NJ-VA

Summer

Uncommon

Asteraceae

Megachilidae

Megachile (Sayapis) inimica

CT-DE-MA-MD-NJ-NY-PAVA-WV

Summer

Uncommon

Asteraceae

Bidens, Helianthus

Halictidae

Dieunomia (Dieunomia) heteropoda

MD-NJ-VA

Fall

Rare

Asteraceae

Chrysopsis, Heterotheca, Pityopsis

Andrenidae

Andrena (Callandrena s.l.) fulvipennis

DE-MD-NJ-NY

Fall

Rare

Asteraceae

Chrysopsis, Heterotheca, Pityopsis

Andrenidae

Perdita (Hexaperdita) bishoppi

DE-MD-NJ

Fall

Rare

Asteraceae

Chrysopsis, Heterotheca, Pityopsis

Andrenidae

Perdita (Hexaperdita) boltoniae

DE-MD-NJ-NY-VA

Fall

Rare

Asteraceae

Cirsium

Megachilidae

Osmia (Helicosmia) chalybea

DE-MD-NJ-NY-VA-WV

Summer

Rare

Host Plant Family

Host Plant Genus

Bee Family

Bee Genus (Subgenus) species

Asteraceae

Cirsium

Megachilidae

Asteraceae

e.g. Cirsium

Asteraceae

Present at Mt. Cuba

Recorded States

Peak Activity

Status

Osmia (Helicosmia) texana

MD-VA-WV

Summer

Rare

Apidae

Melissodes (Heliomelissodes) desponsus

CT-DE-MA-MD-ME-NH-NJNY-PA-RI-VA-VT-WV

Fall

Common

e.g. Vernonia

Apidae

Melissodes (Eumelissodes) denticulatus

CT-DE-MA-MD-NJ-NY-PAVA-VT-WV

Fall

Uncommon

Asteraceae

e.g. Helianthus

Apidae

Melissodes (Eumelissodes) agilis

CT-DE-MA-MD-ME-NH-NJNY-PA-RI-VA-VT-WV

Summer

CommonUncommon

Asteraceae

e.g. Helianthus

Megachilidae

Megachile (Sayapis) pugnata

CT-DE-MA-MD-NH-NJ-NYPA-VA-VT-WV

Summer

Uncommon

Asteraceae

Euthamia, Solidago

Andrenidae

Andrena (Callandrena s.l.) braccata

CT-MA-MD-ME-NH-NJ-NYPA-RI-VA

Fall

CommonRare

Asteraceae

Euthamia, Solidago

Andrenidae

Andrena (Cnemidandrena) hirticincta

CT-MA-MD-ME-NH-NJ-NYPA-RI-VA-VT-WV

Fall

Common

Asteraceae

Euthamia, Solidago, Symphyotrichum

Colletidae

Colletes simulans

CT-MA-MD-ME-NH-NJ-NYPA-RI-VA-VT-WV

Fall

Common

Asteraceae

Helianthus

Andrenidae

Andrena (Callandrena s.l.) accepta

MD-NJ-NY-VA

Fall

Rare

Asteraceae

Helianthus

Andrenidae

Andrena (Callandrena s.l.) aliciae

CT-DE-MA-MD-NJ-NY-PAVA-WV

Summer

Rare

Asteraceae

Helianthus

Andrenidae

Andrena (Callandrena s.l.) helianthi

CT-MA-NH-NJ-NY-PA-VA

Summer

Uncommon

Host Plant Family

Host Plant Genus

Bee Family

Bee Genus (Subgenus) species

Recorded States

Peak Activity

Status

-Rare Asteraceae

Helianthus

Megachilidae

Paranthidium (Paranthidium) jugatorium

NJ-MD-NY-VA-WV

Summer

Rare

Asteraceae

Krigia

Andrenidae

Andrena (Callandrena s.l.) krigiana

CT-MA-MD-NH-NJ-NY-PAVA-WV

Spring

Uncommon

Asteraceae

Packera

Andrenidae

Andrena (Callandrena s.l.) gardineri

MD-VA-WV

Spring

Uncommon

Asteraceae

Pyrrhopappus

Halictidae

Lasioglossum (Hemihalictus) lustrans

DE-MD-VA

Summer

Rare

Asteraceae

Rudbeckia

Andrenidae

Andrena (Callandrena s.l.) rudbeckiae

DE-MD-NJ-NY-PA

Summer

Rare

Asteraceae

Solidago

Andrenidae

Andrena (Cnemidandrena) canadensis

CT-MA-ME-NH-NJ-NY-RI-VAVT

Fall

CommonUncommon

Asteraceae

Solidago

Andrenidae

Perdita (Perdita) octomaculata

CT-DE-MA-MD-ME-NH-NJNY-RI-VA-VT-WV

Fall

CommonUncommon

Asteraceae

Solidago

Colletidae

Colletes solidaginis

CT-MA-MD-NH-NJ-NY-VA-VT

Fall

Uncommon -Rare

Asteraceae

Solidago, Symphyotrichum

Andrenidae

Andrena (Callandrena s.l.) asteris

CT-DE-MA-MD-ME-NH-NJNY-PA-RI-VA-VT-WV

Fall

Common

Asteraceae

Solidago, Symphyotrichum

Andrenidae

Andrena (Callandrena s.l.) placata

CT-MA-MD-ME-NH-NJ-NYPA-RI-VA-VT-WV

Fall

Common

Asteraceae

Solidago, Symphyotrichum

Andrenidae

Andrena (Callandrena s.l.) simplex

CT-DE-MA-MD-NH-NJ-NY-

Fall

Common

Present at Mt. Cuba

Host Plant Family

Host Plant Genus

Bee Family

Bee Genus (Subgenus) species

Recorded States

Peak Activity

Status

Present at Mt. Cuba

PA-RI-VA-WV Asteraceae

Solidago, Symphyotrichum

Andrenidae

Andrena (Cnemidandrena) nubecula

CT-DE-MA-MD-ME-NH-NJNY-PA-RI-VA-VT-WV

Fall

CommonUncommon

Asteraceae

Solidago, Symphyotrichum

Andrenidae

Pseudopanurgus aestivalis

CT-MA-MD-ME-NH-NJ-VT

Fall

Rare

Asteraceae

Symphyotrichum

Andrenidae

Andrena (Callandrena s.l.) asteroides

MD-NJ-PA-VA

Fall

Rare

Brassicaceae

Arabis, Cardamine

Andrenidae

Andrena (Scaphandrena) arabis

CT-DE-MA-MD-NJ-NY-PAVA-WV

Spring

Uncommon

Campanulaceae

Campanula, Triodanis

Colletidae

Colletes brevicornis

MD-NJ-VA-WV

Spring

Uncommon

Convolvulaceae

Calystegia, Ipomoea

Apidae

Cemolobus ipomoeae

MD-PA-VA-WV

Summer

Rare

Convolvulaceae

Calystegia, Ipomoea

Apidae

Melitoma taurea

DE-MD-NJ-PA-VA-WV

Summer

Common

Cornaceae

Cornus

Andrenidae

Andrena (Gonandrena) fragilis

CT-DE-MA-MD-ME-NH-NJNY-PA-RI-VA-WV

Summer

Common

Cornaceae

Cornus

Andrenidae

Andrena (Gonandrena) integra

CT-MA-ME-MD-NJ-NY-PAVA-VT

Summer

Uncommon

Cornaceae

Cornus

Andrenidae

Andrena (Gonandrena) perisimulata

CT-MA-ME-NH-NY

Summer

Uncommon

Cornaceae

Cornus

Andrenidae

Andrena (Gonandrena) platyparia

CT-MA-MD-NH-NJ-NY-PA-VA

Summer

Uncommon

Cucurbitaceae

Cucurbita

Apidae

Peponapis (Peponapis) pruinosa

CT-DE-MA-MD-ME-NH-NJNY-PA-RI-VA-VT-WV

Summer

Common

Host Plant Family

Recorded States

Peak Activity

Host Plant Genus

Bee Family

Bee Genus (Subgenus) species

Status

Curcubitaceae

Cucurbita

Apidae

Xenoglossa (Eoxenoglossa) strenua

MD-VA

Summer

Uncommon

Ericaceae

Colletidae

Colletes validus

CT-DE-MA-ME-MD-NH-NJNY-PA-RI-VA

Spring

Uncommon

Ericaceae

Gaylussacia, Vaccinium

Andrenidae

Andrena (Conandrena) bradleyi

CT-DE-MA-MD-ME-NH-NJNY-PA-RI-VA

Spring

CommonUncommon

Ericaceae

Kalmia, Lyonia, Vaccinium

Andrenidae

Andrena (Scrapteropsis) kalmiae

CT-MA-ME-NH

Spring

Uncommon

Ericaceae

Lyonia

Andrenidae

Perdita (Alloperdita) novaeangliae

CT-MA-RI

Summer

Uncommon

Ericaceae

Lyonia

Melittidae

Melitta (Cilissa) melittoides

CT-MA-MD-NH-NJ-PA-VA

Summer

Rare

Ericaceae

Lyonia, Vaccinium

Colletidae

Colletes productus

CT-MA-MD-NH-NJ-VA-WV

Summer

Uncommon -Rare

Ericaceae

Rhododendron

Andrenidae

Andrena (Andrena) cornelli

CT-MA-MD-NJ-NY-PA-VA

Spring

Uncommon

Ericaceae

Vaccinium

Andrenidae

Andrena (Andrena) carolina

CT-DE-MA-MD-ME-NH-NJNY-PA-RI-VA-WV

Spring

CommonUncommon

Ericaceae

Vaccinium

Andrenidae

Panurginus atramontensis

MD-NJ-VA

Spring

Rare

Ericaceae

Vaccinium

Megachilidae

Osmia (Melanosmia) virga

CT-DE-MA-MD-ME-NH-NJNY-PA-RI-VA-WV

Spring

Uncommon

Ericaceae

Vaccinium

Melittidae

Melitta (Cilissa) americana

CT-MA-NJ-NY

Summer

Uncommon -Rare

Present at Mt. Cuba

Host Plant Family

Recorded States

Peak Activity

Host Plant Genus

Bee Family

Bee Genus (Subgenus) species

Status

Ericaceae

Vaccinium

Melittidae

Melitta (Cilissa) eickworti

MD-NJ-NY-WV

Spring

Rare

Ericaceae

Vaccinium

Apidae

Habropoda laboriosa

CT-DE-MA-MD-ME-NH-NJNY-PA-VA

Spring

CommonUncommon

Fabaceae

Cercis

Apidae

Habropoda laboriosa

CT-DE-MA-MD-ME-NH-NJNY-PA-VA

Spring

CommonUncommon

Fabaceae

Galactia, Strophostyles

Megachilidae

Megachile (Megachiloides) integra

MD-NJ

Summer

Rare

Fabaceae

Strophostyles

Megachilidae

Trachusa (Heteranthidium) dorsalis

Summer

Rare

Geraniaceae

Geranium

Andrenidae

Andrena (Ptilandrena) distans

CT-MA-MD-NH-NJ-NY-PA-RIVA

Spring

CommonUncommon

Hydrophyllaceae

Hydrophyllum

Andrenidae

Andrena (Euandrena) geranii

MD-NH-NJ-NY-PA-VA-VT-WV

Spring

Uncommon

Hydrophyllaceae

Nemophila, Phacelia

Megachilidae

Hoplitis (Robertsonella) simplex

DE-MD-NJ-VA-WV

Spring

Rare

Hydrophyllaceae

Phacelia

Andrenidae

Andrena (Euandrena) phaceliae

MD-VA-WV

Spring

Rare

Hydrophyllaceae

Phacelia

Andrenidae

Andrena (Micrandrena) lamelliterga

MD-PA-VA

Spring

Rare

Lamiaceae

Monarda

Andrenidae

Perdita (Perdita) gerhardi

MD-NJ-VA-WV

Summer

Rare

Lamiaceae

Monarda

Andrenidae

Protandrena abdominalis

MD-NJ-PA-VA-WV

Summer

Rare

Lamiaceae

Monarda

Halictidae

Dufourea monardae

CT-MA-NJ-NY

Summer

Rare

Liliaceae

Erythronium

Andrenidae

Andrena (Leucandrena) erythronii

CT-MA-MD-ME-NH-NJ-NYPA-VA-WV

Spring

Uncommon

Present at Mt. Cuba

Host Plant Family

Host Plant Genus

Bee Family

Bee Genus (Subgenus) species

Liliaceae

Uvularia

Andrenidae

Malvaceae

Hibiscus

Onagraceae

Present at Mt. Cuba

Recorded States

Peak Activity

Status

Andrena (Derandrena) uvulariae

MA-MD-NH-NJ-NY-PA-VAWV

Spring

Rare

Apidae

Ptilothrix bombiformis

CT-DE-MD-NJ-NY-PA-VA-WV

Summer

CommonUncommon

Oenothera

Apidae

Melissodes (Apomelissodes) fimbriatus

Summer

Rare

Onagraceae

Oenothera

Apidae

Svastra (Anthedonia) compta

MD-NJ-PA

Summer

Uncommon

Onagraceae

Oenothera

Halictidae

Lasioglossum (Sphecodogastra) oenotherae

CT-MA-MD-NH-NJ-NY-PAVA-WV

Summer

Uncommon

Onagraceae

Oenothera

Megachilidae

Megachile (Megachiloides) oenotherae

Spring

Rare

Polemoniaceae

Polemonium

Andrenidae

Andrena (Euandrena) polemonii

Spring

Rare

Pontederiaceae

Pontederia

Apidae

Florilegus (Florilegus) condignus

MD-NJ-VA

Summer

Rare

Pontederiaceae

Pontederia

Apidae

Melissodes (Apomelissodes) apicatus

CT-DE-MA-MD-ME-NH-NJNY

Summer

Uncommon -Rare

Pontederiaceae

Pontederia

Halictidae

Dufourea novaeangliae

CT-MA-MD-ME-NH-NJ-NYPA-RI-VA-VT

Summer

CommonRare

Portulacaceae

Claytonia

Andrenidae

Andrena (Ptilandrena) erigeniae

CT-DE-MA-MD-NH-NJ-NYPA-VA-WV

Spring

Common

Primulaceae

Lysimachia

Melittidae

Macropis (Macropis) ciliata

CT-MA-MD-ME-NH-NJ-NYPA-RI-VA

Summer

Uncommon -Rare

Host Plant Family

Recorded States

Peak Activity

Host Plant Genus

Bee Family

Bee Genus (Subgenus) species

Status

Primulaceae

Lysimachia

Melittidae

Macropis (Macropis) nuda

CT-MA-ME-NH-NJ-NY-PA-RIVT-WV

Summer

Uncommon -Rare

Primulaceae

Lysimachia

Melittidae

Macropis (Macropis) patellata

CT-MA-MD-NJ-NY-PA-RI-VAVT

Summer

Rare

Primulaceae

Lysimachia

Melittidae

Macropis (Macropis) steironematis

Summer

Rare

Rhamnaceae

Ceanothus

Andrenidae

Pseudopanurgus virginicus

MD-VA-WV

Spring

Rare

Rhamnaceae

Ceanothus

Andrenidae

Pseudopanurgus pauper

CT-MA-MD-NJ-NY-PA-RI-VAWV

Summer

Rare

Rosaceae

e.g. Fragaria

Andrenidae

Andrena (Micrandrena) melanochroa

CT-MA-MD-ME-NH-NJ-NYVA-WV

Spring

Uncommon

Rosaceae

Potentilla

Andrenidae

Panurginus potentillae

CT-MA-MD-NJ-NY-VA

Spring

Uncommon -Rare

Rosaceae

Potentilla, Waldsteinia

Andrenidae

Andrena (Derandrena) ziziaeformis

CT-DE-MD-NJ-NY-PA-VA-WV

Spring

Uncommon -Rare

Rubiaceae

Houstonia

Andrenidae

Pseudopanurgus virginicus

MD-VA-WV

Spring

Rare

Salicaceae

Salix

Andrenidae

Andrena (Andrena) clarkella

CT-MA-ME-NH-NY-RI-VT-WV

Spring

CommonRare

Salicaceae

Salix

Andrenidae

Andrena (Andrena) frigida

CT-MA-MD-ME-NH-NJ-NYPA-RI-VA

Spring

CommonUncommon

Present at Mt. Cuba

Host Plant Family

Recorded States

Peak Activity

Host Plant Genus

Bee Family

Bee Genus (Subgenus) species

Status

Salicaceae

Salix

Andrenidae

Andrena (Andrena) macoupinensis

MD-PA-VA

Spring

Uncommon

Salicaceae

Salix

Andrenidae

Andrena (Micrandrena) illinoiensis

MD-NY-VA

Spring

Rare

Salicaceae

Salix

Andrenidae

Andrena (Micrandrena) nigrae

CT-DE-MA-MD-ME-NH-NJNY-PA-RI-VA-VT-WV

Spring

Uncommon

Salicaceae

Salix

Andrenidae

Andrena (Micrandrena) salictaria

CT-MA-MD-ME-NH-NJ-NYPA-RI-VA-VT-WV

Spring

CommonRare

Salicaceae

Salix

Andrenidae

Andrena (Parandrena) andrenoides

MD-NJ-NY-VA

Spring

Rare

Salicaceae

Salix

Andrenidae

Andrena (Parandrena) nida

MD-NH-NJ-NY-RI-VA-WV

Spring

Uncommon

Salicaceae

Salix

Andrenidae

Andrena (Parandrena) wellesleyana

CT-MA-RI

Spring

Uncommon

Salicaceae

Salix

Andrenidae

Andrena (Thysandrena) bisalicis

CT-DE-MA-MD-ME-NH-NJNY-PA-RI-VA-VT-WV

Spring

CommonUncommon

Salicaceae

Salix

Andrenidae

Andrena (Trachandrena) mariae

MD-NH-NJ-RI-VA-WV

Spring

Uncommon

Salicaceae

Salix

Andrenidae

Andrena (Trachandrena) sigmundi

CT-MA-ME-NH-RI-VT

Spring

Common

Salicaceae

Salix

Andrenidae

Andrena (Tylandrena) erythrogaster

CT-MA-MD-ME-NH-NJ-NYPA-RI-VA-VT-WV

Spring

CommonUncommon

Salicaceae

Salix

Andrenidae

Perdita (Perdita) maculigera

Fall

Rare

Saxifragaceae

Heuchera

Colletidae

Colletes aestivalis

DE-MA-MD-NY-VA

Summer

Rare

Scrophulariaceae

Agalinis

Andrenidae

Perdita (Perdita) gerardiae

MD-NJ

Fall

Rare

Present at Mt. Cuba X

Host Plant Family

Recorded States

Peak Activity

Host Plant Genus

Bee Family

Bee Genus (Subgenus) species

Status

Scrophulariaceae

Agalinis

Apidae

Anthophorula (Anthophorisca) micheneri

Fall

Rare

Scrophulariaceae

Penstemon

Megachilidae

Osmia (Melanosmia) distincta

CT-MA-MD-ME-NH-NJ-NYPA-VA-VT-WV

Spring

Uncommon

Solanaceae

Physalis

Andrenidae

Perdita (Perdita) halictoides

MA-MD-NH-NJ-NY-VT

Summer

Uncommon -Rare

Solanaceae

Physalis

Colletidae

Colletes latitarsis

CT-MA-MD-ME-NJ-NY-PAVA-WV

Summer

Uncommon

Solanaceae

Physalis

Colletidae

Colletes willistoni

MD-NJ-NY-PA-VA

Summer

Rare

Solanaceae

Physalis

Halictidae

Lasioglossum (Hemihalictus) pectinatum

CT-DE-MA-MD-NJ-NY-PAVA-WV

Summer

Rare

Verbenaceae

Verbena

Andrenidae

Calliopsis (Verbenapis) nebraskensis

CT-NJ

Summer

Rare

Violaceae

Viola

Andrenidae

Andrena (Iomelissa) violae

CT-DE-MA-MD-NH-NJ-NYPA-VA-WV

Spring

CommonUncommon

Present at Mt. Cuba

Appendix B. Bee Collections by Host Plant We collected bees visiting flowers of the following 106 plant taxa during the study. It is important to note that since this was a bee fauna inventory and not a plant visitation study, netting technique and effort varied between plant species and the numbers of individuals and species detected are not statistically comparable between plants. The list is sorted by observed number of bee visitor species, and then by the number of collected individuals that yielded that that number of species, which gives at least a preliminary sense of the plants with higher diversity of bee visitors. However, since species richness does not increase linearly as sampling increases, the species per individual ratio must be interpreted with extreme caution (Gotelli and Colwell 2001).

Plant Species

No. of Species

No. of Individual Bees

Salix nigra

Euthamia graminifolia

101

Mertensia virginica

Vernonia noveboracensis

Cirsium discolor

Eurybia divaricata

Packera aurea

Zizia aurea

Hydrangea radiata

Symphyotrichum pilosum

Veronicastrum virginicum

Ilex verticillata

Rubus allegheniensis

Geranium maculatum

Phacelia bipinnatifida

Plant Species

No. of Species

No. of Individual Bees

Cercis canadensis

Eurybia sp.

Rhododendron vaseyi

Hydrophyllum virginianum

Castanea dentata

Penstemon digitalis ‘Husker Red’

Cirsium horridulum

Viola striata

Solidago juncea

Cardamine concatenata

Waldsteinia fragarioides

Eurybia macrophylla

Astilbe biternata

Rudbeckia laciniata

Solidago rugosa

Rudbeckia fulgida var. fulgida

Phacelia purshii

Coreopsis sp.

Enemion biternatum

Plant Species

No. of Species

No. of Individual Bees

Symphyotrichum cordifolium

Penstemon digitalis

Uvularia grandiflora

Cornus amomum

Eurybia spectabilis

Polemonium reptans

Verbena hastata

Ilex glabra

Ficaria verna

Houstonia caerulea

Itea virginica

Penstemon canescens

Rhododendron periclymenoides

Coreopsis tripteris

Collinsonia canadensis

Elephantopus sp.

Leucothoe axillaris

Apocynum cannabinum

Oenothera sp.

Plant Species

No. of Species

No. of Individual Bees

Scilla siberica

Viburnum acerifolium

Cardamine diphylla

Lespedeza cuneata

Penstemon calycosus

Rudbeckia sp.

Helianthus microcephalus

Heuchera americana

Solidago (gigantea?)

Fothergilla major

Asclepias syriaca

Baptisia alba

Calystegia sepium

Erigeron pulchellus

Scutellaria sp.

Stylophorum diphyllum

Tephrosia virginiana

Amelanchier x grandiflora

Anemone canadensis

Plant Species

No. of Species

No. of Individual Bees

Monarda ‘Dark Ponticum’

Pachysandra terminalis

Kalmia latifolia

Erythronium americanum

Pachysandra procumbens

Symphyotrichum puniceum

Asclepias incarnata

Actaea racemosa

Claytonia virginica

Apios americana

Chrysogonum virginianum

Cirsium vulgare

Dicentra cucullaria

Dodecatheon amethystinum

Erythronium americanum

Eupatorium perfoliatum

Jeffersonia diphylla

Monarda ‘Achall’

Polymnia canadensis

Plant Species

No. of Species

No. of Individual Bees

Rhododendron sp.

Sisyrinchium sp.

Solidago sphacelata ‘Golden Fleece’

Teucrium canadense

Tradescantia virginica

Verbesina alternifolia

Vernonia angustifolia ‘Plum Peach’

Eutrochium fistulosum

Galanthus nivalis

Rudbeckia hirta

Stokesia laevis

Mimulus sp.

Solidago sp.

Acer rubrum

Euphorbia corollata