Hoverfly i.d. please

[davemangham]

Is this one of the Melanastoma's?

Approx 7mm total length.




I'm only just beginning to develop an interest in these little beasties, and my field guides to British insects are woefully inadequate (with the exception of Butterflies and Macro Moths), would anyone care to venture an opinion on whether (purely on the basis of identifying a species from a photo such as this), "British Hoverflies" by Stubbs would be a worthwhile investment, providing I could find a copy?

[JRsbugs]

It's a female Platycheirus, I'm tempted to say P. albimanus but I can't see if there's 3 or 4 pairs of spots, however I think it is.

P. albimanus is supposed to be a very common Platycheirus, but as I'm taking more interest in these this year I'm finding anything but! There's a lot of similar species, and details need to be seen such as leg colour and shape as well as for males front tarsi; spots on abdomen including colour, shape and number; face profile, frons dusting and in some cases antennae colour.

Janet

[Geoff F]

P. albimanus is certainly the most likely at this time of the year. And all of the similar species are noticeably smaller.

I mostly see P. albimanus during the Spring but there is a second peak during July/August and I did see a few in the woods during late July.

[JRsbugs]

Geoff, I have had several species just now or in the last three weeks or so.

Including P. manicatus, nielseni (fairly certain)and possible peltatus, europaeus including a melanic form, ambiguus (I feel quite sure), possible tarsalis (and a melanic form!), scutatus, clypeatus, albimanus.

In the last couple of days a very rare one which keys out as sticticus, the male has a long, narrow basal tarsal segment. I have also had a tiny female barely 7mm long which I got pics of again today and could be the female, but I need to see the femora colour so I'm waiting to see what I got today. She was so small she looked more like a big thrips, and almost disappeared when she went into Lythrum salicaria flowers.

They are doing my head in, but I'm getting to grips with them!

These have probably always been around, but I've got the suitable areas for them with suitable flowers in the right places, and I'm looking harder for them in the right places.

[Jason Green]

Afternoon all,

Yes, Platycheirus - could be albimanus. They've been very common locally - huge numbers of females.

Janet, I suggest you post that impressive list + photos on the Hoverfly Recording Scheme website for a UK-based confirmation. Sticticus sounds like a good find, I'll watch with interest.

I must just pop-in the thing about photo IDs being unreliable for a lot of these less-common Platycheirus though, but I suppose it depends on how certain you wish to be, submission to Recording-Scheme wise.

How did you key them, was it ol' Stubbs and Falk?

Take care,

Jason

[JRsbugs]

Jason, I know the pitfalls of identifying from a photo or photos.

I have already placed some on diptera.info, and have shown enough angles and details to be sure enough for the difficult ones. I haven't put them all up yet though, it's starting to get embarrassing. Take a look in the Syrphidae forum there. I have had a lot of males!

So far no-one has ventured to confirm P. sticticus but there is no other which can fit that I can see, and I got a good shot of the front tarsi although it was very windy and dull so I had to hold the flower stem with one hand and take with the other, only got two pics but I've got a lot today.

I have a few (valid) syrphidae keys I found online in an archive, but I do think I need a good book!

[Jason Green]

Have you had replies to any others, such as the manicatus, tarsalis or europaeus if they've been posted? If not I suppose they could be a bit cautious of photos for these ones too.

Maybe Roger will come past post-season.

Apologies for the thread hijack - I'll promptly hand the reigns back over

[davemangham]

Thanks all for the help, especially Janet.

Apologies for not responding in a more timely manner, but for some reason I seem not to be receiving any eMail notifications of responses. Anyone else having similar problems?

From what I read here I guess the investment in a copy of Stubbs & Falk would be worthwhile, if only to guide me down the path of what to look for. Now - does anyone know where I can get a copy?

[Geoff F]

Manicatus should be quite easy as the distinctive dull thorax, often with a couple of faint stripes, should be obvious besides the rather clear spot shapes. For some reason, I am seeing a lot of them this year, but only in one very localised area.

It is probably getting a bit late for tarsalis now so I am thinking that my somewhat unclear possible tarsalis sightings are more likely peltatus. So I have just put them to one side until I get more time.

Being more of a northerly species, I don't have any experience of europaeus but as it belongs to that fiendishly difficult clypeatus grouping I think that an actual specimen may be necessary for a confirmed ID.

Besides hoverflies, I have just started to see some odd looking harvestmen which has caused me to 'scratch my head' for an hour or more without any real answer. And some odd other fly species have just been ditched in the unidentified folder until we get some more serious rain next week!

[Geoff F]

Dave, Stubbs & Falk should be widely available for around £40 although I think it is cheaper if you join the British Entomological & Natural History Society, who are the publishers.

But beware of cheap secondhand earlier copies. You need the 2002 Edition.