Miner bee and 2 hoverflies

[JRsbugs]

Originally Posted by Jason Green

The issue I have is the two pale lines/half-circle on the thorax - they usually signify balteatus, and I'm not aware of these being present on lasiopthalma.

Did you check the pattern on the abdomen, also notice that E. balteatus does not have a dark facial stripe? At least those which I have don't have it.

Identificaion is based on a series a features, not one as I'm sure you are aware. There will always be something which throws us when we can't see all the necessary details, this is where those who have years of experience can sometimes give an ID based on some features which they recognise as specific to one species. Jizz.

I'm not confident in giving a name to the fly in question.

[Geoff F]

To my way of thinking (and believe it or not, I'm no expert) those yellow areas appear somewhat too square on the outer edges for Melangyna species.

It isn't a species that I'm familiar with but I thought their spots were smaller and almost oval shaped. A good view of the scuttellum would have helped.

Those thoracic lines appear in some form on quite a few species and is one of the reasons that made me consider Meliscaeva which can have faint similar stripes.

But perhaps this is one for the Hoverfly Recording Scheme real experts.

[Jason Green]

Originally Posted by JRsbugs

Did you check the pattern on the abdomen, also notice that E. balteatus does not have a dark facial stripe? At least those which I have don't have it.

The abdomen isn't focused sufficiently for me to consider it too much, hence my reticence in basing my ID on it. That said, I don't know why it wouldn't be the dark, late-season version of balteatus - the orange on T1 is close-fitting with it. The 'dark facial stripe' you refer to I believe is the anterior margin of the labium and probably alike in both species, rather than being part of the head. Consider the ventrally-produced extension to the head if that was so

Originally Posted by JRsbugs

Identificaion is based on a series a features, not one as I'm sure you are aware.

True to a degree, though some species have a feature that isn't present on any other of it's type, rather than they all have a different combination of the same features. In this case it's the unique two pale longitudinal, obliquely-truncated apical tips to the thorasic markings of balteatus, which I believe are present here.

I personally can't devote any more time to closely-examining a 'cryptic' photograph, as nice as it is! I have given my reasons, and you've given yours.

...Brian, it's over to you!

[JRsbugs]

Sorry Brian, but I have to post a pic of Episyrphus balteatus to show Jason what the facial stripe (or lack of a vertical stripe, not as Jason seems to think I think) is, as well as how an E. balteatus really looks from a similar angle.

[Lord V]

Thanks for the ID thoughts Janet, Geoff and Jason - appreciated

First hover was definately not balteatus I actually watched it for some time but it was being entirely uncooperative WRT photography.
Brian v.

[Jason Green]

Found it. This image was taken by Toby in November 2008 - a late season balteatus appearing deceptively-marked.

Note first-off, the usual transversely-arranged orange markings are now apparently restricted to elonhgate markings on the lateral margins. On the thorax, you'll notice three sub-shining bands that are obliquely-truncated apically, and a semi-circle towards the thorasic dorsum's posterior margin on an otherwise golden-shining surface. This patterning is the key and ever-present feature that is reliably used to identify balteatus, and isn't affected by seasonal variance. Seeing the afore-posted photograph in reality you'd have no way of knowing this was balteatus either, in my opinion.

As for similarities between the OP's photo and the one by Toby, look at the mostly dark fore and mid-legs. In typically ordinary summer specimens, both the legs and antennae are mostly yellow. Here though, due to puparium exposure it has darkened (and the black abdominal markings increasing their surface coverage) - I believe the thinking on this aspect of their phenology is that darker colours retain heat.

One more:

Showing the darker than normal abdomen, and the broad orange markings on T1 - same as in the OPs picture.

Really though, other than solving curiosity I don't see the point in debating it further. We all have our thoughts as to which it is, but other than the to me, quite apparent presence of balteatus' key feature, it lacks the clincher for anything else (correct me if I'm wrong, anyone!). Fun as it may be 'deciphering' cryptic photographs, other than fully-expanding on reasons for why we think it's such as I have done - the need for identifying it just isn't great enough. Much better, we get out there and carry on recording!

[JRsbugs]

I see you found time Jason.

Really, if I had to choose,I would go with Geoff's suggestion of Meliscaeva auricollis. Reasons?

1) Stripe on face (vertical)

2) It can have some of those unique stripes on the thorax.

3) The spots are variable on this species, with some showing a broader spot on T1, also the shapes do look to very similar from what can be seen. See this specimen..

Diptera.info - Photo Albums: Meliscaeva auricollis (male) (2)

3) The spots are close to the top margin of T2 which can be seen, if it did happen to be Episyrphus balteatus which all of a sudden developed a facial stripe I would expect the 'spots' in an unusual specimen to be futher away from the top or anterior margin. The black 'moustache' shape on E. balteatus may bleed into other areas but you would normally see at least a little yellow below the anterior margin, not showing on the fly in question but is showing on Toby's fly.

As stated here Meliscaeva auricollis has several colour forms.

Look at this one, it shows some faint stripes on the thorax (second pic).

And, if you think there is some likeness to Episyrphus balteatus, that might be because Meliscaeva auricollis was once called Episyrphus auricollis... the fly in the following link is also showing some striping on the thorax.

Diptera.info - Discussion Forum: Melanostoma?

Please take time to read these points Jason, you 'might' get it. All the entomology terminology in the world will not make it correct, nor convince me, I can if I wish use those terms too but really that gets a little boring and takes time to look them up.

[Jason Green]

Evening Brian,

Having just re-read the thread this evening I realise I seem to had missed John Coldwell's post where he put forward that Melangyna. Given his inordinate experience and my respect for his knowledge I am more than happy to go with that.