Soft-bodied Plant Beetle - Dascillus? - Dascillus davidsoni

Moved

Moved from Dascillus. Thanks so much for your comments and thoughtful analysis, Harmut!

… Ken Schneider, 26 May, 2010 - 10:12am

I think I now agree with Ken

that this is D. davidsoni, after having read Horn's key & descriptions & looked at specimen.
Exposure can make a big difference. In Clarissa's photos the irregular, darker transverse bands are better visible. The base color is brown, rather than the darker gray, or nearly black of plumbeus. Also, the 3rd antennal joint is not longer than the 4th, and the elytra don't look like they have rows of deep, coarse punctures as in plumbeus.
As far as length is concerned, females of both spp. reach ~18-20mm, while the males are smaller.

… Hartmut Wisch, 26 May, 2010 - 12:36am

wow. you're good, man.

Moved from Beetles.

… v belov, 23 May, 2010 - 7:18pm

Thanks v -

this one was in my Evans and Hogue field guide (although a suboptimal specimen image). I'm adding some more aesthetically-pleasing images of this same beetle that my wife got with her macro lens and frassing a couple of mine. Likely D. davidsoni based on size and location, perhaps, but I'm not sure how to rule out D. plumbeus, apparently the only other member of this genus in California...

… Ken Schneider, 23 May, 2010 - 8:04pm

I could be wrong,

but I go for D. plumbeus because of the shape of the elytra. I'll check with Jim Hogue tomorrow, he might have specimens.
For now, comparing the type photos with those here I find a better match
with plumbeus with the sides of the elytra slightly concave, then broadening before narrowing more toward the apex. In davidsoni elytral edge is pretty much straight before narrowing toward the apex.
Shto dumayetye? Sorry, I can't figure out how to type cyrillic letters.
On the other hand, I see the irregular crossbands in some of the other photos, which would suggest davidsoni. So, not sure.

… Hartmut Wisch, 24 May, 2010 - 12:50am

что я думаю:

great analysis -- thanks, Hartmut; i'll be following the developments.

… v belov, 24 May, 2010 - 1:40am

Thanks!

For what it's worth, the size really was nearly two centimeters (I use my thumb width as a crude measuring device) - I couldn't find a size range for plumbeus, but my impression from Evans and Hogue was that davidsoni females (?) would be that big.

… Ken Schneider, 24 May, 2010 - 10:08am