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In a different forum, javanerkelens ("Joke" ) posted a picture of what I think is an empty diptera pupa. It has long 'horns' which seem to end in a tuft of hair. This looks like some of the Drosophilidae in Smith's "immatrure stages of British flies". Does anyone here recognise this type of pupa?

http://forum.waar...opic=35537

I will ask her about the size..

thanks in advance, Louis

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Could well be Drosophilidae, though I must say I have never seen horns that long in our native species. But then again I have not seen many.

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Another possibilty is Ephydridae - I'm afraid my grasp of the Dutch language is minimal - is there any indication of where the puparium was found? This might help establish what it is.

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Looking at the image again, it seems that the long processes are anterior, rather than posterior, so it's not an ephydrid. Drosophila funebris is known to have very long pupal horns, so this common and widespread species would be my suggestion.

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The only thing mentioned was that it was found on a leaf.

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yes, the photographers says it was found hanging from a leaf with a feltlike structure (maybe like Cirsium vulgare?) - I interpret this as the underside of a leaf on a living plant. She thinks it was 4 to 5 mm long, without the horns.

Thanks for your suggestions so far, Louis

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PS, Tony,

a pupa of Drosophila funebris is depicted in Smith's (1989) "An introduction to the immature stages of Britisch flies". In this picture the horns aren't that long.
Another question is what could be the function of such long horns? One would think this enables the pupa to breathe when submerged in water, or rotting fruit maybe?

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My mistake - I misread the caption in Shorrocks (Invertebrate Types: Drosophila p.36). I should have said Drosophila immigrans, not funebris. This is a fruit-feeding species, so perhaps the larva fell from a rotting fruit, or was stuck on a bird's beak and was wiped off on the leaf.
The pupal horns are for breathing when the puparium is in deep liquid. The hairs at the tip of the tubes keep the opening at the surface of the liquid, so the whole puparium can be submerged, but continues to breathe.

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Thanks Tony, that's really interesting information. D. immigrans is known from the Netherlands, so it's quite possible it is this species indeed.

Louis