Aculeate Hymenoptera Recorder’s Report 2021 – Adrian Knowles

HYMENOPTERA RECORDER’S REPORT 2021

19

Trans. Suffolk Nat. Soc. 57 (2021)

Steven Falk

The year brought a number of significant records, suggesting that some of our scarcest species are spreading within the county. Arguably one of Britain’s rarest wasps has yet to be recorded anywhere other than Suffolk. The digger wasp Miscophus bicolor was recorded new to Britain in 2003 from Maidscross Hill to the west of Lakenheath and it has been recorded there regularly ever since. In 2014, Tim Strudwick then recorded it from the RSPB’s Lakenheath Fen nature reserve a few miles to the north. This year sees the exciting news of a significant new location, at Wortham Ling on the Norfolk\Suffolk border in vice-county East Suffolk. Here, Hawk Honey took a male on 4 August.

During the year, David Basham has made a number of interesting observations around the village of Clopton, near Woodbridge. These include a female Lasioglossum puncticolle, which is a rare bee in Suffolk, towards the northern edge of its UK distribution in Norfolk and Suffolk. Whilst Lasioglossum species are the “little brown jobs” of the bee-world (as off-putting as all those small, brown warblers for any budding birdwatchers!), this species is actually quite distinctive. The underside of its head has a series of large, shiny ridges and Lasioglossum puncticolle grooves, reminiscent of the throat of a baleen whale, underside of head. in my opinion.

David also recorded a female of the impressively sized Andrena labialis, found on a small patch of rough grassland. This bee is perhaps slightly larger than a honey bee and as such is big for a British solitary mining bee.

The males are relatively easily identified by their extensive yellow facial markings (with only a few Andrena species being thus coloured), but the females are rather more drably marked. Females seem to favour legume-rich sites with plentiful White Clover (Trifolium repens). This is one of only a few modern records for this bee in Suffolk and represents probably the fifth known site in the Andrena labialis Male face County.

In July, also in Clopton, David found a Stelis phaeoptera on a flowering Spear Thistle (Cirsium vulgare). Stelis bees are cleptoparasites (or ‘cuckoos’) of other megachilid bee species such as Osmia, Hoplitis and Heriades, with S. phaeoptera thought to use Osmia leaiana as its host. This appears to be only the second VC25 site noted for this uncommon bee, although its host is much more widespread.

In late June, Hawk Honey organised a recording trip to a gravel pit site in Drinkstone, to the east of Bury St Edmunds, that he had identified as being worth a

Steven Falk

ACULEATE HYMENOPTERA RECORDER’S REPORT 2021 ADRIAN KNOWLES

Suffolk Natural History, Vol. 57

look from online aerial photography. The weather was a bit uncooperative, with largely overcast skies on the day, but several good discoveries were nevertheless still made. These included Sphecodes longulus, which has hitherto largely only been found in the Brecks and the coastal Sandling heaths, plus a single record in the Waveney valley. This is another ‘cuckoo’ species, attacking the nests of the smallest Lasioglossum species. Also recorded were specimens of the rare Lasioglossum pauperatum. The latter record appears to represent the third known site in the County for this nationally threatened bee and a first for vice county West Suffolk.

In July, David Basham organised a return trip to a farm in Witnesham to have a look at what had been attracted to a field of nectar and pollen-rich legumes planted as part of a Countryside Stewardship agreement. There were plenty of the commoner bumblebees foraging here and it was very pleasing to note amongst them several male and female solitary mining bees Melitta leporina. This is the second year in a row that this scarce bee has been recorded from this farm and it represents the largest known population of this species in the County away from the Brecks. The bee Melitta leporina female is known to forage almost exclusively on leguminous flowers, so the planting of these fields appears to have had a direct positive influence on their numbers and success. I also took a specimen of M. leporina from a site near Great Blakenham, on 4 August.

In my 2020 report, I mentioned the discovery of the cuckoo-wasp Sapyga quinquepunctata (Family Sapygidae) in Capel St Mary. During June and July 2021, Hawk Honey observed this wasp at the Suffolk Wildlife Trust’s (SWT) Lackford Lakes nature reserve, which may be a first record for West Suffolk.

In mid-April, I decided to explore the further reaches of the SWT Spouse’s Vale nature reserve. On the edge of an area known as Ford’s Heath is a small sandpit and here I found yet another cuckoo species, this time the nomad bee Nomada zonata.

This bee was only recorded in mainland Britain for the first time in 2016, but is now largely known from scattered records from Kent, Essex, Suffolk and Norfolk. I also caught a specimen from Purdis Heath to the east of Ipswich, on 28 April.

Having told Hawk Honey of the Ford’s Heath pit, he visited the site on 28 May and found two species of particular interest. The first was the potter wasp Odynerus spinipes. This is a rare species in Suffolk, with this possibly being the first observation for West Suffolk. It has the unusual habit of building a small down-turned chimney of sand grains over the entrance to its nesting gallery dug into steep sandy faces. Even more interesting than this, Hawk also caught Pseudospinolia neglecta. This is another cuckoo species (one of the ruby-tailed wasps), and one which parasitises the nests of Odynerus spinipes. This is another new record for West Suffolk and the first Suffolk record of which I am aware for a very long time.

Trans. Suffolk Nat. Soc. 57 (2021)

Steven Falk

20

Melitta leporina female

21

Steven Falk Hawk Honey

HYMENOPTERA RECORDER’S REPORT 2021

I managed to record two further ruby-tailed wasps of interest during the year. On 12 May, a walk to the coast at Stutton Ness on the northern shore of the Stour estuary yielded a record of Chrysura radians. This attacks the nests of wood-nesting bees in the genus Osmia, so its presence here was presumably down to the trees and bushes that line the cliff top rather than the exposed sandy cliff itself.

The genus Chrysis has long been a difficult group to Chrysura radians identify to species level, with previous disagreements even as to how many species were actually within the genus. Whilst this is being resolved by a number of modern texts, the answer is “even more than we thought”! A relatively newly recognised British species (of unknown history in Britain) is Chrysis terminata. This is actually one of the easier species to identify, with four prominent bumps present along a crest running across its ‘brow’. I caught a specimen in the Hardwick Heath open space to the south of Bury St Edmunds on 26 June.

A shake-up of our records of another ruby-tailed wasp appears necessary, with the recent discovery that most records of Hedychridium roseum should actually be attributed to H. caputaureum. Visibly distinguishing the two species appears to be a

Trans. Suffolk Nat. Soc. 57 (2021)

Steven Falk

Entrances to burrows of the potter wasp Odynerus spinipes.

Suffolk Natural History, Vol. 57

fairly esoteric process, being based on the precise distribution of copper-coloured patches on the otherwise blue-green head and thorax. However, it appears that the extent of such copper colouring can be highly variable. If anyone has specimens of H. roseum in their collection, it would repay close inspection and re-evaluation.

In the 2020 Transactions, Mark Ferris announced the discovery of the mining bee Andrena bucephala as new to Suffolk, following his discovery of a female in his garden in the village of Denston to the south-west of Bury St Edmunds. In 2021, Mark managed to repeat his find a few miles from Denston and I subsequently found several females in an orchard near to Bury, so it appears that this species is becoming firmly established in this part of West Suffolk. Another interesting discovery in the same orchard saw the nomad bee Nomada guttulata, possibly only the second Suffolk record. It attacks the nests of the mining bee Andrena labiata, which forages at flowers of Germander Speedwell (Veronica chamaedrys), so it would repay surveying grasslands with this forage plant more closely for this Andrena labiata Male cuckoo-bee and its host.

In October, David Basham and I contributed to a national DNA research project concerning mining bees in the genus Colletes and their associated cuckoo-bee, Epeolus species. The Ivy Bee, Colletes hederae, is a relative newcomer to the British Isles and it appears to come under attack from a species of Epeolus. The question is, is this Epeolus one of the current native species (such as E. variegatus or E. cruciger) that is opportunistically swapping hosts, or is it a new species? A number of samples were collected from the now famous St Mary’s churchyard, Woodbridge, colony of the Ivy Bee to feed into a national study. I was surprised to learn that an eminent Hymenopterist from Salisbury in Wiltshire had been to see this impressive colony in recent years, although numbers appeared to be rather low this summer.

Finally, an erratum and credit to David Basham for a record of the scarce Saxon Wasp Dolichovespula saxonica when a queen turned up in an Ipswich garden in late April 2020. This appears to be the second record for VC25 East Suffolk since the species was first recorded in Britain in 1987.

Adrian Knowles Jessups Cottage London Road Capel St Mary Suffolk IP9 2JR

Trans. Suffolk Nat. Soc. 57 (2021)

Steven Falk

22