I found this large, colourful hoverfly feeding on Yarrow (Achilea millefolium) in the garden this evening. It is a male Volucella inanis, a hornet mimic which is also found in nests of wasps and hornets, where its larvae develop. Spot on, its numbers peak at the beginning of August. The entry in Stubbs and Falk's British Hoverflies notes that its distribution range is expanding north, and being the first time I come across this species, I checked the NBN Gateway: no records for East Yorkshire or anywhere north of the Humber. Another species expanding its range due to climate change? I should start keeping a list.
UPDATE 4/08/2013. Barry Warrington e-mailed me with some more info about the species in East Yorskshire: "V. inanis is scarce in our County. I recently found one a couple of weeks back and having liaised with the YNU Diptera recorder and checked the Watsonian Checklist, my find was the first for East Yorkshire. It is clearly spreading well and quickly, with it being most common in VC63."
Did you check with Roger Morris?
ReplyDeleteI contributed many if not all of the more recent SK48 records on the NBN Gateway, and Paul Leonard (Rotherham Biological Records Officer) would have been the source of the majority of the SK49 ones.
(I haven't seen any in S. Yorks so far this year, and very few in Southern England).