Flesh Fly

[Stan]

another fly with the Canon 100 f2.8 LIS macro

Stan

1/80, f8, ISO 800

[Richard W]

Re: Flesh Fly

Excellent picture, but not a flesh fly. In flesh flies (Sarcophagidae) the lower wing vein at the tip of the wing turns sharply upwards (as in bluebottles and greenbottles) to more or less meet the upper one, while in this photo it carries on straight to the end of the wing. This looks like one of the Anthomyiidae, possibly Anthomyia pluvialis. If you look at pictures e.g. in Chinery's field guide, you can see the difference in the wing venation.

[Tigger]

Re: Flesh Fly

flesh or not its still a stunning shot - well done ++

[Stan]

Re: Flesh Fly

thanks guys

but not a flesh fly

yes, just realised that, flesh flies are much darker anyway. None of the family Anthomyia are mentioned in the Collins book and I have lots of shots this fly and would have called it a cluster fly, based on the description in Collins in respect of the chequered abdomen. Agree though it does look like a Anthomyia pluvialis but that's not the sort of title you would put on a forum - does the family have a common name ?

Stan

PS just noticed that Chinery is the auther of the Collins guide as well

[Richard W]

Re: Flesh Fly

None of the family Anthomyia are mentioned in the Collins book

Is that the book that calls itself the "complete" book of British insects? There were actually 242 species in the family last time I checked. They are very similar to the Muscidae (often called the house fly family, though only one species is common in houses!) which has 286 species. Cluster flies (Pollenia) species belong to the Calliphoridae which is the same family as the bluebottles and greenbottles and has the same wing venation, but they always have pale curly hairs on the thorax. There are 8 species of Pollenia and the only reliable way to tell them apart is by examining the male genitalia, the same is true of the 7 species of greenbottle Lucilia. There are probably hundreds of similar flies that have chequered patterns. Apart from genitalia examination, most species are identified by what we call chaetotaxy, i.e. examining the number and exact position of the numerous bristles on these flies, the photo here shows just how many bristles most of them have!

Basically, there are very few flies which can confidently be identified to species in the field or from even the best photos, often family or perhaps genus level is the best that can be done. So a photo of a greenbottle can correctly be called Lucilia species, but not Lucilia caesar (the one usually shown in books) as there are other externally identical species that are equally common.

I make my living from identifying insects, spiders etc., but don't use any field guides, everything not obvious is collected up for microscopic examination at home. I once asked a book publisher why they put in phrases such as "with this book you can confidently identify everything to species in the field" when it was obviously untrue. He said that decisions such as that were always made by the marketing department, if it would sell more books then it went in, true or not.

[Stan]

Re: Flesh Fly

thanks Richard. Yes it is the "complete" guide which as you say is more for the marketing than anything else and it is lacking not only as far as flies are concerned but butterflies, damselflies etc but dose seem reasonably good for moths.

I suppose for most I am just going to have to call them "a fly" and wait for someone like you to come along with a more positive ID.

If you have a chance, please look at this one - it was only around 3 or 4 mm in size and no detail was visible until zoomed right in on the lcd. Someone on WAB thought it a member of the Dolichopus family but again there are probably hundreds of them

stan

[Richard W]

Re: Flesh Fly

Hi Stan
Yes that's one of the Dolichopodidae and, as you suspected, there are getting on for 300 species. This is a female, some of the males have modified front or middle legs expanded like feathers, which they wave about to court the females. One common species is Poecilobothrus nobilitatus where the male has white wing tips and runs about, often in large numbers, around muddy puddles flashing the wings to attract the girls. it's clearly visible even from a fair distance and easy to recognise once you've seen it.

[Stan]

Re: Flesh Fly

thanks Richard

We did see another one looking very similar but 3 or 4 times the size of this one

stan

[tesarver]

Re: Flesh Fly

Excellent detail Stan

Tom

[Stan]

Re: Flesh Fly

thanks Tom

stan