Aculeate Hymenoptera Recorders’ Report for 2002

NOTES ACULEATE ON THE SUFFOLK HYMENOPTERA LIST OF COLEOPTERA REPORT

63

Aculeate Hymenoptera Recorders’ Report for 2002 The year again saw important discoveries for the county, even though the summer seemed to zoom by so fast. Further survey work at a Breck grassland site near Red Lodge yielded new county records and several other significant finds. One of the most important was the small cuckoo-bee Nomada argentata, which is listed as a Red Data Book species (Falk, 1991 – RDB3, Rare) and is seemingly a new county record. It is a cleptoparasite of the mining bee Andrena marginata (itself Nationally Notable), which means that it lays its eggs within the nest cells of the host Andrena. The Nomada larva hatches first and consumes the food provision of pollen put in place for the host larva, with the eventual death of the host larva if it is not killed directly. The survival of Andrena marginata (and therefore, indirectly, the Nomada) is dependent upon the maintenance of large stands of Scabious flowers, from which the Andrena gathers pollen and probably also nectar. A further Scabious-dependent bee, Andrena hattorfiana (RDB3), has also been recorded from this site.

Another modern county record came from the same site, the mining bee Lasioglossum laevigatum. Morley (1936) recorded the species from Wangford Warren in 1929 but, despite being only nationally Local with a distinct southern bias, this bee does seem to be quite scarce in East Anglia. Further interesting species recorded from this site include the spider-hunting wasp Caliadurgus fasciatellus, which to my knowledge has not been recorded in the county since 1902, the bee Hylaeus annularis (only recorded from Center Parcs, Elvedon elsewhere in the county) and the national Biodiversity Action Plan wasp Cerceris quinquefasciata and its cleptoparasite Hedychrum niemelai (both Red Data Book, RDB3, Rare).

Survey work for Essex and Suffolk Water at Barsham in the north-east of the county produced the second county record for the spider-hunting wasp Dipogon variegatus. This small, unobtrusive species can be encountered in suburban gardens (Day, 1988) but is likely to go undetected. It utilises small cavities in woodwork, mortar and even small snail shells as nest sites, provisioning the cells with paralysed spiders (usually Xysticus cristatus: Thomisidae) in Britain.

The lack of recent recording occasionally gets shown up by surprising “rediscoveries”, although the loss of habitats since Morley’s day must also account for the lack of recent records for many species. Morley (1936) described the small mining bee Lasioglossum nitidiusculum (as Halictus nitidiusculus) as “quite common” but my record from Bawdsey cliffs this year is the first modern record of which I am aware. The small Lasioglossums are tricky creatures to identify and there is a total lack of modern texts to help the enthusiast that might strive to attempt their study. This probably helps to account for the lack of recording for this species, but habitat loss and the dependence upon specialised habitat conditions (such as the presence of large quantities of Scabious flowers, as outlined above) is a critical factor that is now endangering many of our Hymenoptera species.

Another very pleasing re-discovery was the ruby-tailed wasp (family Chrysididae) Chrysura radians, sent to me by Justin Gant. Claude Morley

Trans. Suffolk Nat. Soc. 39 (2003)

64

Suffolk Natural History, Vol. 39

took a couple of specimens at the beginning of the last century, but Justin’s find is apparently the first since then. Like many ruby-tails, it was taken from a wooden fence post, within which it was probably searching for host wasp nests within which to lay its own eggs. Wooden telegraph poles, dead Elms and other areas of bare, dry wood are also good hunting sites to find these wasps.

A brief day’s rambling along the crumbling cliffs at Bawdsey yielded several other interesting finds. These included the small velvet-ant Smicromyrme rufipes, which is a wingless wasp rather than an ant. It favours areas of loose open sand and is unusual for a parasite in having a very catholic taste when it comes to its host, attacking the nests of spider-hunting wasps, digger wasps, and several Genera of solitary bee. Despite this broad taste it remains Nationally Notable and with very few modern records in Suffolk.

Another good find was the ruby-tailed wasp Hedychrum niemelai. As previously reported, this wasp is presumed to parasitise the Red Data Book and Biodiversity Action Plan wasp Cerceris quinquefasciata and so the presence of the Hedychrum at Bawdsey would suggest that the Cerceris should also be present.

In last year’s report the discovery of the extremely rare bee Lasioglossum sexnotatum at Martlesham Heath and Orford was noted. Despite several return visits to Martlesham this year the species was not re-found, but further attempts will be made during 2003.

If anyone is interested in forming a study group to further our knowledge of the solitary bees and wasps, I’d be pleased to hear from you because I can’t survey the whole county myself! If you are interested in catching and preserving these insects or tend to come across them as a “by-catch” to your main area of interest, I can provide the identification service, so you need not feel daunted about trying to identify them yourself.

References Day, M.C., (1988). Spider Wasps, Hymenoptera: Pompilidae, Handbooks for the Identification of British Insects, Vol. 6, Part 4.

Falk, S. J. (1991). A review of the scarce and threatened bees, wasps and ants of Great Britain, Research and Survey in Nature Conservation No. 35, Nature Conservancy Council.

Morley, C. (1935). The Hymenoptera of Suffolk, Portio Prima, Trans. Suffolk Nat. Soc., 3: 17-52.

Morley, C. (1936). The Hymenoptera of Suffolk, Portio Secunda, Trans.

Suffolk Nat. Soc., 3: 132-162.

Adrian Knowles

12 Blackbrook Road, Great Horkesley, Colchester, Essex CO6 4TL

Trans. Suffolk Nat. Soc. 39 (2003)