Fly with finger shaped scutellum

Bruce Williams · #1 (**permalink**) 11-06-2010, 10:18 PM

Stony Stratford, Bucks.

Size: Pls. see scale bar.

Help with identification appreciated as always:

Bruce

Matt Smith · #2 (**permalink**) 11-06-2010, 10:29 PM

Female Beris chalybata.

Bruce Williams · #3 (**permalink**) 12-06-2010, 08:37 AM

Thanks for your help Matt - much appreciated. I assume the eyes help determine the gender?

Bruce

Jason Green · #4 (**permalink**) 12-06-2010, 08:49 AM

Morning Bruce,

Quote:

Originally Posted by Bruce Williams

I assume the eyes help determine the gender?

Yes - the gap here signifies female, male Stratiomyids have massive eyes, proportionally bigger than Syrphids. Additionally the males of chalybata have swollen hind metatarsi.

Matt Smith · #5 (**permalink**) 12-06-2010, 03:07 PM

Quote:

Originally Posted by Bruce Williams

Thanks for your help Matt - much appreciated. I assume the eyes help determine the gender?

Bruce

Yes - in males the eyes touch in the middle of the face (similar to many hoverfly species), in females there is a gap (the "face") between the eyes. In your photo we can see there is a definate gap beteen the eyes.