All Dark Pepsis - Pepsis mexicana

Pepsis mexicana

I'm pretty sure this is Pepsis mexicana. It is a female due to it having six abdominal segments (as opposed to the male having seven). Females can straighten their antennae like the male, so antennal convolution or lack of isn't a reliable sexing method.

The other candidates are P. grossa and P. terminata. P. grossa can have melanochromatic wings like this species, but the fore femora of females have long hairs, which this specimen does not have. P. terminata has a much broader whitish hyaline on the apices of the wings and the antennae are often bicolored.

Comparing to Ron's photos, he used a flash which really brought out the iridescent blue on the overall specimen. You can see hints of the iridescence on this specimen.

… George Waldren, 30 June, 2007 - 3:39am

Yes...I hate that

Not trying to be a jerk to anyone trying to sex Pompilids on whether or not their antennae curl, but it's not reliable at all. Males of some species can slightly curl their antennae, as well, so it REALLY doesn't work. Number of segments in the antennae (except in Pepsis grossa) and number of abdominal sternites (as noted above) is most reliable.

I also agree with George's assessment of which species this is. In fact, I'm glad he came upon it since I really had no backing from anyone else when I suggested that ID for this set about a year ago. I think this is about as safe as you'll get with a Pepsis ID from a photo.

… Nick Fensler, 30 June, 2007 - 6:26am

You were right on about P. me

You were right on about P. mexicana. The only Pepsis I can ID from photos with any confidence are the all-dark specimens (with some exceptions depending on the photo).

… George Waldren, 30 June, 2007 - 12:27pm

Moved

To Pepsis guide page for now.

… Beatriz Moisset, 26 July, 2006 - 3:10pm

My guess...

would be P. mexicana but there are several all dark species of Pepsis in Arizona. They are pretty difficult to identify from photos anyway, but being all dark narrows it down a little more. I live in Ohio so I'm not as familiar with the genus at species level as I am with the other pompilid genera, and since Eric lives in Arizona he might have a better idea. This is just my best guess.

… Nick Fensler, 15 July, 2006 - 5:27pm

Thanks, Nick. If I remember w

Thanks, Nick. If I remember what Eric showed me, P. mexicana was quite small. I tried to show the size of this one with one photo that included a bit of my hand, but it's hard to say exactly how big. It was big though.

… Richard C. Hoyer, 15 July, 2006 - 5:32pm

Then...

...it's probably one of the other all dark species found in Arizona. I've never seen specimens of P. mexicana, in fact the only all black Pepsis I've seen were undetermined neotropical species from Ecuador. I guess I wasn't going off of very much info:-)

… Nick Fensler, 15 July, 2006 - 7:29pm