Eristalis transversa question - Eristalis transversa

Moved

… Kelsey J.R.P. Byers, 23 September, 2015 - 2:55am

Two ways to tell

You are correct, the eye shapes and the eye gaps are qualities that can be used to sex many different types of flies and also a few other insects too.
The abdomens of this species have reliable features and all of the males have that distinctive notch on the center-line of the slightly wider stripe.
Here is another guy's image:
♂

What do you think?
Yes, I agree, it should be on the "info tab!

… Bob Biagi, 22 September, 2015 - 7:31pm

info tab

Thanks Bob. Do you know of other hoverflies with that much pattern difference? I will surely keep my eyes open.

… Martha O'Kennon, 23 September, 2015 - 6:07am

My personal favorite in this

My personal favorite in this regard is Lejops curvipes:

and

Sphaerophoria also has a lot of sexual dimorphism.

… Kelsey J.R.P. Byers, 23 September, 2015 - 7:17am

Interesting choices!

Kelsey, the one on the right is a female that is incorrectly labelled as a male and the one on the left is an unlabeled male. Is that correct?
Wow, that species is another one that has an "info" tab that seriously needs an update!

… Bob Biagi, 23 September, 2015 - 9:00am

Correct! Here's a nice pictu

Correct! Here's a nice picture set showing the differences.

Thanks for pointing out the error - I've edited the image to re-id it as female. I'll add some info to the page as well.

… Kelsey J.R.P. Byers, 23 September, 2015 - 9:18am

Amazing!

Thanks, Kelsey. That IS radical dimorphism. So far Michigan hasn't reported this one but I will keep my eyes peeled.

Right now seems to be hoverfly time. I have a good planting of lots of colors of New England asters, and every once in a while I see something zooming quietly along and then stopping in mid-air. So I'll be out there looking for new ones.

… Martha O'Kennon, 23 September, 2015 - 8:00am

Amazing

I don't know how to delete a comment. This one got sent out in midstream so don't look at it!

… Martha O'Kennon, 23 September, 2015 - 7:59am

thanks!

Thanks for answering that question. I suppose the dimorphism (if that's what you would call it) happens in other flies - this was just the first time I've seen it.

… Martha O'Kennon, 22 September, 2015 - 7:39pm

Good spot! Yes, in most syrp

Good spot! Yes, in most syrphid species the males have eyes that touch, while the females are separated; in a few genera the males' eyes are just closer, while not touching, and thus it's harder to sex them by looking at the eyes.

… Kelsey J.R.P. Byers, 23 September, 2015 - 2:55am

You're right

That one was very hard to spot just looking at the eyes. I'm always looking for more ways to sex the boys from the girls. Lucky in this case the pattern was helpful. :-)

… Martha O'Kennon, 23 September, 2015 - 6:10am