Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Upcoming Events

2018 BugGuide Gathering in Virginia July 27-29: Registration and Discussion

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Photos of insects and people from the 2013 gathering in Arizona, July 25-28

Photos of insects and people from the 2012 gathering in Alabama

Photos of insects and people from the 2011 gathering in Iowa

Photos from the 2010 Workshop in Grinnell, Iowa

Photos from the 2009 gathering in Washington

Copestylum marginatum - Copestylum

Copestylum marginatum - Copestylum
Fremont, Alameda County, California, USA
August 18, 2008
Copestylum marginatum is a Copestylum with two spots in front of the scutellum (see text from
Synopsis of the North American Syrphidae).

Bug Guide does not list this species.
The following Bug Guide photos are also of Copestylum marginatum:
78061, 69745, 98563, 185988, 146542, 174382, 117401, 117396

I think a new species should be added for Copestylum marginatum.

Moved from Copestylum.

The spots in front of the scutellum are not diagnostic for C. marginatum. I don't have any references in front of me, but I recall there being at least two or three NA species with the combination of bushy aristae and yellow spots in front of the scutellum. At least some of the images you linked are probably C. marginatum, but I don't know if they are definitively identifiable from images. Also note that 122499 is not C. marginatum (maybe C. florida?).

Yes, and C. lentum is one of those
with two spots on the scutellum. Yesterday, I looked at some specimens at the Natural Hist. Museum of LA County & was reminded why I had put a question mark on my photos (see comments below), lacking an actual specimen.

In Williston, he differentiates Copestylum marginatum from Copestylum lentum by the pile and yellow of the dorsum.

Thanks for Caution
Thanks for cautioning us about using the two spots as diagnostic. I have removed 122499 from list.

It is not for me to identify these as C. marginatum but I would like to see BugGuide at least have a species listing for them when they ARE identified. Maybe for C. florida too.

Good point, Alice,
and I'm glad you bring it up.
Two of the posts you list are mine, which I posted as Copestylum marginatum ? after looking at a series of identified specimens at Cal State Northridge. I had added the questionmark because I didn't have specimens for careful comparison, and didn't have the time to check whether any superficially similar species exist where ID comes down to a matter of genitalia.
I don't know whether there's been a revision of this since Williston's 1886 description, and hope a dipterist who knows this genus can chime in.
I've made a note of this & will check with Jim Hogue at Cal State Northridge next week. Though preoccupied with bunches of other things, I'll catch a specimen if I'll remember.

Should I move it?
Would you like me to move it to Genus Copestylum for now?

Yes, genus level
is the safe move for now in my opinion. Hopefully we can get beyond genus. Thanks for the initiative, & thus reminder! With so many insects it hard to keep up.

Thanks for researching and posting this, Alice.
The references to so many other posts will help the editors when species is determined on this one. Here's hoping!

Look similar
to Copestylum marginatum in Texhoma, OK, with their unusual antennae.

Comment viewing options
Select your preferred way to display the comments and click 'Save settings' to activate your changes.