In Search of Hypomeron

Best description via good pic

Best description via good picture of Hypomeron that I've found.

https://www.researchgate.net/figure/Detailed-terminology-for-the-anterior-hypomeral-region-procoxae-removed_fig19_315709775

… Glen Forister, 4 February, 2019 - 4:28pm

Elytral suture.

Stephen, have you looked at the elytral suture? If it is widened noticeably at the posterior, then it is likely Plateumaris. This is a highly visible difference under magnification. If there is a more definitive characteristic, I would really appreciate knowing, and I'll re-address my current specimen identifications accordingly:-) Good luck!

… Eric R. Eaton, 5 April, 2006 - 7:14pm

Differences

I've put the differences I gleaned from Arnett's American Beetles on the guide page, with some info from Downie and Arnett too.

Two of the clearer differences have to do with the sutural difference you mention, and differences in host plants. I was able to identify one beetle as Donacia even without a view of the suture, because it had a waterlily host plant, and no Plateumaris has a waterlily host.

Two other differences, unfortunately, were clouded by the word "usually." Arnett says Donacia usually has truncate elytral apices while Plateumaris has rounded ones. He also says that on Donacia, the hypomeron of the pronotum has "broad pubescent area in most species" while this area is usually glabrous in Plateumaris.

--Stephen

Stephen Cresswell
Buckhannon, WV
www.stephencresswell.com

… Stephen_WV, 6 April, 2006 - 4:09am

hypomeron

(pl. hypomera) (of pronotum). That portion of the pronotum which is visible from the ventral side; when there is a lateral pronotal carina, this is the portion below that carina (the pronotal disc being above it). The postcoxal projection in Polyphaga is part of the hypomeron.

… Lynette Elliott, 5 April, 2006 - 6:43pm

good definition and..

see fig. 2 on page 20 of Morphology of the prothorax and procoxa in the New World
Cryptocephalini (Coleoptera: Chrysomelidae: Cryptocephalinae)

… Phillip Harpootlian, 5 April, 2006 - 6:53pm

Thank-you

Thank-you, Lynette, that is a big help!

--Stephen

Stephen Cresswell
Buckhannon, WV
www.stephencresswell.com

… Stephen_WV, 5 April, 2006 - 6:48pm

Your welcome

For future searches, I found it at the site listed as #1 here. I just added that one today, after finding it while searching for your word.

… Lynette Elliott, 5 April, 2006 - 6:50pm