ACULEATE HYMENOPTERA RECORDERS’ REPORT FOR 2006-2007

RUNNING HEAD

53

ACULEATE HYMENOPTERA RECORDERS’ REPORT FOR 2006–2007 ADRIAN KNOWLES Coastal soft cliff survey 2006/2007 The invertebrate conservation organisation “Buglife” has recently compiled a nationwide survey and assessment report for coastal soft cliff habitats, which have long been known to support some of the nation’s rarest insects and the Hymenoptera are no exception to this. Suffolk has a good resource of this habitat, stretching from Corton Cliffs and Kessingland in the north, through Covehithe Cliffs at Benacre, Easton Cliffs at Southwold, Minsmere Cliffs at Dunwich Heath down to Bawdsey near Felixstowe in the south.

In order to assist with this project, Ivan Wright (a fellow Hymenopterist, from Oxfordshire) visited the Corton and Kessingland cliffs during 2006 and 2007 and has furnished us with some very important records in the process.

My thanks go to Ivan for providing me with a full copy of his records. Some of the more interesting records are given below: Andrena humilis is a Nationally Scarce solitary mining bee with only a handful of modern (i.e. post-Morley) records from the Brecks and around Ipswich and Hadleigh. Ivan’s record is the first coastal location for this species, despite the fact that coastal cliff tops and landslips appear to be a favoured habitat for this bee. Interestingly, in 2007 Ray Ruffell provided me with a further specimen of this species, taken from an area of set-aside land near Kesgrave, Ipswich. This illustrates two points: firstly, the potential value of set-aside land in the early phase of its development when they can be extremely flower-rich if weedy habitats, and secondly that nationally rare or scarce species aren’t always restricted to rare, pristine or fragile habitats – they often just need large quantities of flower-rich grassland.

Andrena proxima is a nationally Rare (Red Data Book 3) solitary mining bee and Ivan’s record was the first in Suffolk for 70 years, although two further specimens have since been taken from different parts of the county.

One of these was taken by Colin Plant from around Haverhill – a much underrecorded part of the county. Coastal soft rocks and landslips are, again, a favoured nesting habitat for this species.

Caliadurgus fasciatellus is a spider-hunting wasp, with the record from Kessingland being only the sixth for the county and the first for north-east Suffolk.

Didineis lunicornis is a Nationally Scarce digger wasp. Two specimens were found by Ivan Wright from separate locations along the Kessingland Cliffs, these being the first records in Suffolk since Claude Morley’s record from Felixstowe cliff on 20 August 1900. It is thinly scattered along the Essex and north Kent coasts and quite likely still occurs at other locations along the Suffolk coast.

Another significant re-find is for the cuckoo-bee Nomada leucophthalma taken from Kessingland, not recorded since before 1936 in Bentley woods by Morley. This bee is a brood parasite of the solitary mining bee Andrena clarkella, which is one of the earlier bees to be active in spring, being found from early March to mid-May.

Trans. Suffolk Nat. Soc. 44 (2008)

54

Suffolk Natural History, Vol. 44

Similarly, Ivan took specimens of the mason wasp Odynerus spinipes from Kessingland, these being the first county records for over 70 years. Morley gives locations at Frostenden and Redgrave prior to 1936. Odynerus wasps are industrious nest-builders, building a small usually down-turned “chimney” of sand particles over the entrance hole to their nests (Plate 7). It is thought that this may be a means of deterring access by predators and parasites and the chimney is dismantled when the nest has been fully provisioned. These chimneys are an easy piece of evidence that these wasps are nesting and I would welcome any further observations of such chimneys by members.

The spider-hunting wasp Priocnemis agilis is yet another species for which Ivan’s work, this time at Corton, represents the only modern record in Suffolk.

Morley took the species in his Monk Soham garden prior to 1935.

Before Ivan’s surveys the small metallic green solitary mining bee Lasioglossum smeathmanellum was known from only one other site in Suffolk, the King’s Forest near Thetford. In reality this bee is quite widely distributed in England and Wales and the paucity of records is doubtless more to do with the lack of recording effort than genuine rarity in the county, although it is likely to be rather scarcer than the similar looking Lasioglossum morio.

Finally, Gorytes quadrifasciatus is a solitary digger wasp for which Ivan’s record comprises only the fifth modern record, all of which come from the coast.

Other news During 2007 I helped collect specimens for an interesting genetics study being undertaken as part of a Hymettus (formerly Aculeate Conservation Group) project looking at possible speciation. Andrena marginata is a solitary mining bee that is thinly scattered across southern England and south Wales, but there are possible differences in its populations. In some localities it forages on small Scabious Scabiosa columbaria and/or Field Scabious Knautia arvensis whilst in others it forages on Devil’s-bit Scabious Succisa pratensis. These two groups of forage plants do not have overlapping flowering periods and the activities of the foraging bees therefore tend to be separate, also. There is no known site where A. marginata forages on both Small Scabious and then Devil’s-bit Scabious. This would tend to suggest a potential divergence in the A. marginata gene pool, since Small Scabious foragers would never meet Devil’s-bit Scabious foragers. There is even the potential for two distinct but visually very similar species to be involved. All I had to do was catch specimens! The trick then was over to researchers at the University of Liverpool who dissected out flight muscles, extracted and replicated RNA genetic material and then undertook gene matching analysis. Preliminary studies of A. marginata appear to be inconclusive, with little if any genetic difference between populations, regardless of their forage source, but this foraging behaviour could drive an eventual genetic drift that leads to the formation of two species, although not necessarily in the life time of this Recorder! I would like to thank Hymettus for providing expenses support for this project.

Trans. Suffolk Nat. Soc. 44 (2008)

ACULEATE HYMENOPTERA RUNNING HEAD RECORDER’S REPORT

55

Surveying for this Andrena marginata project at King’s Forest near Thetford revealed an important chalky grassland ride at the southern end of the Forest, which yielded many other important Hymenoptera records, including the nationally Rare (Red Data Book) bees Lasioglossum brevicorne and Andrena hattorfiana, the digger wasp Cerceris quinquefasciata and its cuckoo-wasp brood parasite Hedychrum niemelai. Like A. marginata, A. hattorfiana collects pollen almost exclusively from Field and small Scabious flowers. This site has also yielded what appears to be a new county record, the Nationally Scarce (Nb) solitary mining bee Melitta tricincta. This species is largely restricted to south-east England and is often encountered in Essex wherever its sole pollen source (Red Bartsia Odontites vernus) is found in quantity. Its absence from the Suffolk fauna up until its discovery here may reflect the lack of recording effort although it is a species that is thought to be increasing its populations (Edwards, 1998).

A wildlife survey grant from the Forestry Commission enable some detailed recording of other parts of King’s Forest and other land in their ownership. This yielded a number of interesting records, including: the small mining bee Andrena minutuloides at only its third known Suffolk locality; the Red Data Book (RDB3) digger wasp Diodontus insidiosus at its fourth modern locality; and the Nationally Scarce mining bee Lasioglossum quadrinotatum.

Following my previous article in White Admiral extolling the virtues of garden natural history, I also made a number of interesting discoveries in the comfort of my own garden. The most notable of these was the digger wasp Psenulus pallipes, this being only the second modern record for Suffolk. This small, slender wasp nests in dead stems, including roof thatch, and disused insect holes in dead wood and is one of the many species that can utilise the various “insect homes” comprising bundles of cut canes, straw etc. that are now commercially available. The same is true of another uncommon Suffolk digger wasp recorded from my garden, Passaloecus gracilis.

Nigel Cuming provided some significant records from the Sandlings in 2006, including specimens of the mining Andrena argentata and its brood parasite bee Nomada baccata. A. argentata is only known in Suffolk from the Minsmere/Dunwich Heath area. Also in 2006, Paul Lee took the first modern specimen of the small, arboreal ant Lasius brunneus. This Nationally Scarce ant usually nests in large, old craggy trees and especially oaks and given the number of old parks with such trees in Suffolk it is perhaps surprising that this species has not been recorded previously.

Perhaps the most surprising record from 2006 was the discovery of two female Colletes halophilus bees from Ragwort Senecio jacobaea from Maidscross Hill near Lakenheath. As its specific name suggests, this species is considered to be a “halophile” or salt-loving species on the grounds that it is restricted to coastal habitats and generally collects pollen from Sea Aster Aster tripolium on saltmarshes. Lakenheath is about as far as you can get from the sea in Suffolk but the Brecks area in general supports quite a suite of otherwise coastal species from many insect groups that have their only inland location there. This helps to reflect the extreme importance of the Brecks for

Trans. Suffolk Nat. Soc. 44 (2008)

56

Suffolk Natural History, Vol. 44

invertebrate conservation in general. Despite searches in 2007 and 2008, no further specimens have been obtained.

References Edwards, R. ed. (1998). Provisional atlas of the aculeate Hymenoptera of Britain and Ireland. Part 2. Huntingdon: Biological Records Centre.

Adrian Knowles Jessups Cottage London Road Capel St Mary Ipswich IP9 2JJ

Trans. Suffolk Nat. Soc. 44 (2008)