Hoverfly pupa - almost ready to emerge

[Bruce Williams]

Took these pics at Stockgrove Country Park, Beds this afternoon. Pupa was under a large piece of rotting bark. It looks pretty well developed to me. The abdomen is clearly visible and you can also make out the large red(ish) eyes and the developing antennae.

Ok I'm ready to be corrected but I'm pretty sure this is a hoverfly pupa. Would appreciate confirmation (or otherwise) and species if possible.



Bruce

[haematocephalus]

Bruce,

I'd agree that this is a hoverfly. Strictly speaking it is a "puparium" rather than a pupa - many (most?) fly larvae form their pupa inside the hardened skin of the final-instar larva, so that what looks like the outer skin of the pupa is actually the larval skin with a pupa inside, hence "puparium".

No idea of the species I'm afraid! The black and yellow stripes visible in the photo suggest one of the typical Syrphini hoverflies (i.e. tribe Syrphini, which includes Syrphus ribesii and many others). Alan Stubbs say in his book that "Puparia from over-wintering [Syrphinae] larvae are often more hidden and may be found when searching leaf litter" which seems to tie in with this.

Did you keep the puparium to see what emerges?

Martin

Martin Harvey

[Bruce Williams]

Martin - Thanks for your very helpful reply - sent me off on some profitable Googling . Not that many puparium pics on the web (well I didn't find many)but quite a lot of interesting info..

I hadn't though about collecting the puparium but now you've mentioned it I'll try collecting it tomorrow (weather permitting).

Bruce