Hoverfly id please.

[glsammy]

Can aynone identify this small Hoverfly?










Many thanks.

[Jason Green]

Hi Graham, great shots!

I think it fits the bill for Melanostoma mellinum.

[glsammy]

Thanks Jason.

[Geoff F]

To me, the abdomen looks quite long and the yellow patches appear to have rather rounded corners so I wonder about Melanstoma scalare instead.

But tricky to seperate from a photo and definitely a Melanstoma either way.

Perhaps an expert can decide.

[Jason Green]

Originally Posted by Geoff F

To me, the abdomen looks quite long and the yellow patches appear to have rather rounded corners so I wonder about Melanstoma scalare instead.

Hi Geoff,

See:

17/7/08

My first M. scalare
...from the Gallery

Rounded corners yes, but I usually find M. scalare to have rather more angled, bracket-like yellow markings.

[JRsbugs]

Originally Posted by Jason Green

Hi Geoff,

See:

17/7/08

My first M. scalare
...from the Gallery

Rounded corners yes, but I usually find M. scalare to have rather more angled, bracket-like yellow markings.

Yours is a female though Jason, the marks are different to the males. The thing to look for on females is the two white 'dust' triangles between the eyes which nearly meet in M. sclare, and their halteres are green. M. millenum has much smaller dust triangles, males are much more difficult to tell apart but I would go for M. millenum, the halteres are yellow. I'm not sure what the difference is in the marks, pics I have seen of M. scalare show a flatter top on the marks but what other differences there is I don't know.

Janet

[Dogghound]

I think its M.scalare based on markings (which are variable) and abdominal shape. The correct way to tell males apart is by the size of the plate on the underside of the abdomen.

[Jason Green]

...ah, simple then - you just need some way of turning it over!!

Sorry if it isn't M. mellinum then Graham - please don't freeze me for it

[Geoff F]

I've tried looking at the back of my screen but it doesn't work. So we have to try to make do with the upper side.

My understanding of seperating the 2 species, courtesy of Stubbs & Falk, is that M. scalare males have a longer and slimmer abdomen, but you really need to see both side by side to be sure. And with scalare the first set of abdominal yellow markings is approximately semi circular with a straight edge against the abdomen side.

Mellinum males (and the females) have a shorter wider abdomen with the first set of yellow spots being more 'egg' shaped and at an approx 45 degree angle to the abdomen centre line.

M. scalare females have similar yellow spots to M. mellinum which is where Janet's advice becomes important.

And then there is Melanstoma Form A; but, as far as I am aware, that is a rather rare upland anomaly which needn't concern us now.