Flies, Flies and more flies for ID

[WilliamvN]

So, my camera and I spent a long weekend in Dorset pestering insects, only to get home to a couple of Collins guides which, while great for some groups (butterflies, earwigs etc) are... other for the larger/less charismatic groups, leaving me with a fair number of flies which i really cannot identify:

3 which I would call hoverflies (quite possibly in error)

1)

2)

3)

Two which I think are Tachinids (Possibly the same species?)

4)
(Based on someone else's ID'd photo, I'm working under it being Eriothrix rufomaculata, but don't know what the diagnostic feature is, so it could be anything for all I know)

5)

Some which I'm just calling Big for now:

6)

7)

8)

9)
(This last one was more Medium than Big, but looked similar to some of the other ones I'm calling Big)

And then six midgetly little ones

10)

11)
(Actually had greenish eyes, but the camera flash made it look red. the only one of these in a garden, about a dozen swarming around some mint by a pond)

12)

13)

14)

15)

With the exeption of number 11, all of them were found in grassland with some trees. All, with no exceptions, were in non-coastal Dorset between the 30th of July and the 2nd of August. If people can identify them to family level (or preferably beyond), I'll be very grateful - even more so if they could let me know what the giveaway is.

Thanks,

William.

[JRsbugs]

Hi William, welcome to WAB.

#1 Syrphidae, female Platycheirus (not albimanus as that has mostly orange front femora). I'd need to see the spots better, then it might be difficult.

#2 Syrphidae (just realised it was different, a male!). Could be a Cheilosia sp. but I can see a spot on the abdomen which is confusing, it doesn't match Melanostoma mellinum. Hmmmmm.

#3 Syrphidae, Sphaerophoria female possible S. scripta but females can't normally be done from photos.

#4 & 5 Tachinidae, Eriothrix rufomaculata is correct. There is a similar one, Mintho rufiventris which has red femora and is scarce, but I have it.

#6 & 7 Sarcophagidae, could be Sarcophaga carnaria which is quite common and is huge, up to 19mm but there's a lot of these which look similar.

#8 I think is Calliphoridae, possible Pollenia sp.

#9 Anthomyiidae male, they are difficult so you need good close up and expert advice although I have learnt to recognise a few simply because I put them up for ID on diptera.info and I research old threads there.

#10 Tachinidae, looks like Siphona geniculata which is very small, one I have about now.

#11 Dolichopodidae, I could key it if I could see more.

#12 Could be Chloropidae, this one is very similar but often not identifiable.

#13 Phoridae, possibly Megaselia sp.

#14 Drosophilidae, looks like Scaptomyza sp.

#15 Anthomyiidae, probably Pegomya sp. of which there are many and are difficult to ID.

There's no giveaway other than taking photos, spending hours and a few years researching them. Then you might start to recognise a few.

[JRsbugs]

#2 could be Platycheirus rosarum, male Platycheirus usually have expanded fore tarsi but this one doesn't.

That makes #1 also a possible P. rosarum!

http://syrphidae.3644.co.uk/srph/pl.html

[triops]

Identifying flies from a key is interesting and rewarding. The best key is "A key to the familied of British Diptera, by D.M. Unwin. It is, I think, at present out of print, but would be worth searching for. All the Unwin keys are written for non-specialists and easy to use.

[Matt Smith]

No. 4 is Eriothrix rufomaculata, No. 5 is probably the same species but I can't see any red, but that may just be the angle of the shot.

No 10 ia a Siphona species, S.geniculata is the most likely but they are not that easy to ID to species.

Could I have the details of these for the Tachinid Recording Scheme please.

Thanks

Matt

[WilliamvN]

First off, thanks!

Second, If it adds anything to the ID, the barely-visible spot on the abdomen of the second hoverfly (Platycheirus-ish) is the very edge of an orangish-yellow band on the first few segments of its abdomen - does that help clarify at all?

Finally, regarding hoverfly number 3, the Sphaerophoria, there was a hoverfly in the same area (5-10 metres away) the next day which I'm cautiously calling a male S. scripta - - does that have any bearing on the female's ID?

Adding Unwin to my "List of Books to Buy when I have money" - thanks.

Edit - Matt, Number 5 had the same shape reddish patch, slightly more orange. As for details - how much detail do you want? Just co-ordinates, or site description as well? Both were within 10 metres of 50°49'51.82"N, 1°57'59.38"W - private property, formerly agricultural now grassland with some large oaks and a lot of small ones. Both photographed 31st of July, 2011

[WilliamvN]

Googling pictures of Platycheirus rosarum, the abdominal marking was in keeping with that - although I remembered it slightly yellower than most of the pictures on the web - so it fits.

[Matt Smith]

Originally Posted by WilliamvN

Edit - Matt, Number 5 had the same shape reddish patch, slightly more orange. As for details - how much detail do you want? Just co-ordinates, or site description as well? Both were within 10 metres of 50°49'51.82"N, 1°57'59.38"W - private property, formerly agricultural now grassland with some large oaks and a lot of small ones. Both photographed 31st of July, 2011

William

Details are fine - I have a "who, where, what and when" now for the record. Grid References are what all recording schemes use for mapping purposes, but it is possible to convert the lat long reading.

Matt

[JRsbugs]

Originally Posted by WilliamvN

Finally, regarding hoverfly number 3, the Sphaerophoria, there was a hoverfly in the same area (5-10 metres away) the next day which I'm cautiously calling a male S. scripta - - does that have any bearing on the female's ID?

No it doesn't, not even if they were in the same place at the same time.

Adding Unwin to my "List of Books to Buy when I have money" - thanks.

Unless you can get the details needed to be seen in order to determine a family your money will be wasted. Experience is the best route, spend a lot of time looking at posts and the diptera families on diptera.info. There's way too many families to make it easy, and some have been changed from one family to another so a book will soon be outdated as taxonomy in diptera is forever evolving.

[Jason Green]

Afternoon William,

Originally Posted by triops

Identifying flies from a key is interesting and rewarding. The best key is "A key to the familied of British Diptera, by D.M. Unwin. It is, I think, at present out of print, but would be worth searching for. All the Unwin keys are written for non-specialists and easy to use.

Unwin's key is great, a worthy purchase - try Pemberley Books

Whilst it's true that some families are occasionally merged, it's not that common and all the key will do is outline the features present in each. Reading through such literature gives you all you need to know the differences at play, but for certain families you'll need a voucher specimen to examine under a microscope - not expensive, by far the quickest way to learn and free of the usual photographic/prohibitive draw-backs as you'll see from resultant IDs this thread!

Take care,

Jason