Hymenoptera Recorder’s Report 2017.

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Suffolk Natural History, Vol. 53

HYMENOPTERA RECORDER’S REPORT 2017 ADRIAN KNOWLES For a number of years now, the Fields Studies Centre at Flatford Mill has run a course on the identification of bees and wasps. As one might expect, suddenly congregating several ardent Hymenopterists in one place is likely to yield interesting results and so it has, in the last couple of years. Late in 2016, it was drawn to my attention that the year’s course had come across the cleptoparasitic (“cuckoo”) bee Stelis breviuscula.

This species attacks the nests of another bee, Heriades truncorum, which is, itself, a relative new-comer to the county, first being seen in 2008. The Heriades has been expanding its range northwards from its Surrey/Sussex stronghold for some years, so it was perhaps inevitable that its cleptoparasite would follow it.

Then, the 2017 course yielded the first Suffolk record for over 100 years for the very small mining bee Lasioglossum pauperatum. Claude Morley notes an 1899 capture from Copdock. It is known from a wide scatter of sites around Colchester in north-east Essex, so it was perhaps only a matter of time before it wandered once more back into Suffolk. Or perhaps it has been here all along... Hawk Honey, an enthusiastic attendee at the FSC course, managed to capture the first record within East Suffolk for the “cuckoo” bee Coelioxys rufescens. The only other known modern Suffolk sites for this bee are at Center Parcs, Elveden and in the King’s Forest near West Stow.

Last year’s report announced the surprising discovery of another small Lasioglossum new to Suffolk. This was L. sexstrigatum, a species not long added to the British list on the basis of records in Surrey, Sussex and Kent. Its sudden arrival at Purdis Heath, Ipswich, was remarkable. Its discoverer, David Basham, managed to repeat the trick this year, with a second female caught at the same site, in late March.

Thus, the 2016 specimen might not be just a vagrant, but the vanguard to a small population at this site.

The ruby-tailed wasp Chrysura radians is another recent arrival to Suffolk, being first recorded in 2002. In the last couple of years, I have recorded this Nationally Scarce wasp twice: from waste ground near Sproughton and also Minsmere. Jerry Lee also took this wasp from nearby Dunwich Heath during the summer. The Sproughton site yielded several other scarce species, including the small cuckoo bee Sphecodes niger, Heriades truncorum and the six-banded digger wasp Cerceris quinquefasciata.

The Minsmere catch was part of a “bioblitz” event organised by the RSPB, to which SNS Recorders were invited. Despite weather conditions that were indifferent at best, several interesting finds were made, in addition to the Chysura. The Nationally Endangered mining bee Lasioglossum sexnotatum was observed foraging at flowers of a small Buckthorn (Rhamnus cathartica) bush near the visitor centre. This is the most northerly Sandlings record in Suffolk for this bee, although for sheer latitude, the Breckland records maintain the record overall. The Minsmere reserve has been relatively well worked for its Hymenoptera, partly as a result of contract surveys carried out by Mike Edwards. It was therefore something of a surprise to be able to claim a new reserve record, in the form of the mining bee Andrena labiata. Although

Trans. Suffolk Nat. Soc. 53 (2017)

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SUFFOLK SOLITARY BEES

listed as a Nationally Scarce species, it is known from a very thin scatter of records across most of the county, but this is the first coastal record north of the Deben estuary. It mainly forages on Germander Speedwell (Veronica chamaedrys) but also visits Greater Stitchwort (Stellaria holostea), both very common plants, so its scarcity cannot be attributed to a scarce diet. An even scarcer Suffolk species found on the day was the digger wasp Ectemnius ruficornis, this being known in Suffolk from only a handful of sites around Ipswich and in Breckland.

During his work on the Dunwich Heath complex, Jerry Lee has recorded numerous species of spider-hunting wasp. These are elusive creatures that flick around low to the ground and invariably duck out under the rim of a rapidly advancing net, rather than flying upwards. However, Jerry’s use of static traps, aimed primarily at collecting other insect groups, is a more profitable way of collecting these wasps. The most notable of his finds was a strong colony of Evagetes pectinipes, another relatively new arrival in Suffolk. Until recently, this wasp was only known from two sites in the very east of Kent, but it is another species that has suddenly started to spread northwards and westwards.

Hawk Honey has also had some success in gleaning interesting records of spiderhunting wasps, with the discovery of Arachnospila minutula from Lackford Lakes Suffolk Wildlife Trust reserve and A. trivialis from Flixton.

I would like to thank Miles Barne of the Sotterley Park estate for granting permission for myself, David Basham and Jerry Lee to visit the park in June of this year. The park, a SSSI, contains a large number of veteran trees, which are likely to support important assemblages of dead-wood invertebrates, including beetles, as well as those bees and wasps that nest there, often utilising old galleries of woodboring beetles. Probably the most exciting find on the day was a good colony of White Admiral butterflies in an ancient woodland ride! However, the day’s catch later revealed several interesting species. Most notable was the very small digger wasp Passaloecus insignis. It has been recorded twice in Suffolk since 2000. Also of interest was the minute wasp Stigmus solskyi, although this had previously been recorded in Sotterley Park in 2003.

Other interesting records over the last year or so include: Methocha articulata – this rather ant-like wasp (the females being wingless) had not been seen in Suffolk for 15 years until David Basham noted it at Purdis Heath, Ipswich in June 2016. In it was seen on several occasions by Mike Edwards and Stuart Roberts in the Walberswick-Dunwich area and again at Dunwich in 2001.

Andrena florea – following its recent arrival in Suffolk, this bee continues to be found in new localities, such as Hawk Honey’s observation near Cockfield Hall, in June.

Gorytes laticinctus – this is a relatively large black and yellow digger wasp. It is known from a thin scattering of sites across the county. Hawk Honey recorded it from Weybread in north Suffolk – a much under-recorded part of the county that may hold many interesting species along the river valley.

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

Trans. Suffolk Nat. Soc. 53 (2017)