Suffolk Natural History, Vol. 45
Heriades truncorum – New to Suffolk
In 2008, a landowner in the Higham area of south Suffolk invited Recorders from the Society to visit his extensive property to gather information about its wildlife. Amid an all too brief and rain-interrupted season, the author paid a visit to some areas of dry pasture and small plantations on 1 July, collecting only a modest number of solitary bees and wasps. Two of these, however, turned out to be a male and female of the small megachilid bee Heriades truncorum, a species not previously recorded in Suffolk. This small, but quite robust solitary bee (Plate 1) is considered to be nationally threatened, being placed within the British Red Data Book for insects. Shirt (1987) listed it as RDB3 “Rare”, whilst Falk (1991) placed it within the category RDBK “Insufficiently known” on account of doubts over its true status and distribution in the country. The core range of this species has long been the heathlands of Surrey, with other localities in Hampshire, Sussex and Middlesex. In recent years it appears to have started spreading, with localities around the Thames estuary in north Kent and increasingly in south Essex (P. Harvey, pers. comm.). In 2007 it was recorded in Colchester, then the most northerly record for this species in Britain. The Suffolk specimens extend its known British range considerably to the north and east. One might suggest that this spread is another sign of global warming, allowing the spread of a species previously restricted to the mildest climate in the south-east of the country. This might well be the case, but it may also involve the possibility of this being a relatively new addition to the British fauna, still “finding its feet” within the ecology of the English countryside. Whilst this bee has been recorded in the Surrey heaths for over 100 years, it has been suggested that it may have arrived in this country artificially in imported timber. This supposition is based on the belief that the bee requires the resinous sap of conifer trees to seal its nest tunnels, with such conifers not being a native part of the lowland England flora. This reliance on conifer sap is, however, by no means universally accepted, so the deduction about its status as an introduction is perhaps dubious. Heriades truncorum nests in cavities, such as holes in dead wood, fence posts and the hollow stems of old Bramble bushes. It appears to favour Ragwort (Senecio jacobaea) as a source of pollen and nectar, although a number of other plants are also cited in the literature as having been visited. Is it then coincidence that the two Suffolk specimens were swept from Ragwort flowers from a small area of ungrazed dry, sandy grassland next to a small plantation of conifers?! Time will tell. References 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, Peterborough: Nature Conservancy Council Shirt, D. B., ed. (1987). Insects, British Red Data Books, 2. Peterborough: Nature Conservancy Council. Adrian Knowles Jessups Cottage, London Road, Capel St Mary, Ipswich IP9 2JJ
Trans. Suffolk Nat. Soc. 45 (2009)
Antje Schulte Plate 1: Solitary bee Heriades truncorum L. found at Higham, new to Suffolk in 2008 (p. 10).