Halictus eurygnathus had been considered extinct in Britain but was rediscovered at seven sites. It forages primarily on Greater Knapweed.
Warwickshire entomologist Steven Falk has recently completed a major study of the bees and wasps of fifteen downland sites in East Sussex. The image-rich report is now available for download.
Download Report [PDF 4.5MB]
227 species of bee and wasp were recorded including many rarities. Most notable amongst these was a solitary bee, Halictus eurygnathus, which had not been seen in Britain since 1946 and was considered nationally extinct. But reports of its demise were clearly premature as it was eventually found at seven sites. Females rely very heavily upon greater knapweed as a pollen source, and with this new information, it should be possible to conserve it and hopefully help it to spread.
The study also revealed the important role that arable field margins, flowery fallow fields and blossoming shrubs such as blackthorn play in supporting bees on the Downs. One of Britain’s rarest mining bees Andrena niveata was found to forage primarily from flowers of charlock and hedge-mustard at the edges of rape crops, a relationship that had not been noted anywhere previously.
The study also revealed that some species are in trouble in East Sussex including Britain’s largest mining bee Andrena hattorfiana which forages on scabiouses. The study also failed to rediscover Culluman’s bumblebee which was last recorded in Britain in 1926 and seemingly had a good population in the Seaford area.
Steve also recorded the two-winged flies (Diptera) in the areas he visited and this will be subject to a future report. Hopefully the study will help the various landowners and land managers of the South Downs to promote these important insects, especially given the growing international concern regarding declining pollinators. Steven is also keen to encourage local naturalists to investigate less popular insect groups of the Downs.