Sunday 30 August 2015

Red-legged Wasp

I mentioned a wasp in the previous post, and have now had time to take a stab at identifying it. It was about 20mm long, with very distinctive red tops to its legs. I think it's a black slip wasp, Pimpla instigator, which lays its eggs in the pupae of butterflies, where the larva feed on the blood of the pupa. Which probably explains why it was hanging around near the buddleia.

4 comments:

  1. You find the most wonderful insects.... It is not a wasp; see how short are the antenna. The buddleia would not be the food plant for the butterflies' pupae, so maybe the reason the insect was hanging around is that it visits the flowers for nectar in the same way as the butterflies (or just coincidental). It is not immediately visible in my handbook and so further reading is required. Well done Jon.

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  2. There are several species closely related to St Mark's Flies that can be very difficult to tell apart. St Mark's Flies are so called because they appear close to St Mark's Day, 25th April, but what I didn't know was that in the late summer, the Heather Fly (Bibio pomonae) hatches in large numbers on moorlands; it looks very similar to the St Mark's Fly, but the base of its legs are redish. Yours has a small head which makes it female. Completely harmless.

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  3. Sheila writes, "Looks like Bibio pomonae, the red leg heather fly. See http://www.diptera.info/forum/attachments/bibio2_5.jpg

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  4. Many thanks to Sheila and Derryck for putting me right. Jon

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