Wedge-shaped beetle - Ripiphorus diadasiae

Moved

Moved from Ripiphorus sexdens.

… Ron Hemberger, 11 May, 2018 - 8:53pm

This would appear to be R. diadasiae based on the key

Given antennae colouration.

… James Bailey, 11 May, 2018 - 6:55pm

Thanks! I think you and Aaron have it right.

I've moved the images.

… Ron Hemberger, 11 May, 2018 - 8:52pm

Moved tentatively based on Dr. Thomas's comment

Moved from ID Request.

… v belov, 10 June, 2010 - 10:20am

Dr. Thomas and =v= : Please see comments here

Info on the bees, which could shape ID, was not available at the time this was posted. Please see Dr. Ascher's comments:

… Ron Hemberger, 10 June, 2010 - 7:33pm

Info on the bees

thanks, Ron! you can check the key and spp. accounts in(1) -- what i see in that paper definitely supports Mike's suggested ID

… v belov, 11 June, 2010 - 3:35am

Fine with me, =v=

Just wanted to be sure, since Dr. Ascher had it otherwise. I am no good with keys and know precious little about insect parts. Intend to keep it that way!

… Ron Hemberger, 11 June, 2010 - 11:06am

Male?

I assume that this is a male and that the females have simpler antennae.

… Beatriz Moisset, 10 June, 2010 - 7:27am

My assumption, too.

Still hoping for something definitive, but am pretty sure we're right.

(Written later) Someone's added sex symbols to a couple of images, and I've marked the rest.

… Ron Hemberger, 10 June, 2010 - 6:35pm

I suspect it is genus Ripiphorus

but am not certain

… John S. Ascher, 9 June, 2010 - 11:12pm

Ripiphorus sexdens Linsley & MacSwain

Matches this is general form and coloration and distribution.

… Michael C. Thomas, 10 June, 2010 - 9:28am

Male antenna coloration and species determination

Might this be R. diadasiae rather than R. sexdens?

The relevant terminal couplet in Linsley & MacSwain's 1951 key(1) for males reads:

4a) Tarsal claw with ten inner teeth; antennae distinctly darker near apex. 8.5-10 mm. California...........................R. diadasiae
4b) Tarsal claw with seven or eight inner teeth; antennae concolorous from base to apex. 6-7 mm. Southern California to Washington.......R. sexdens

Also, in Linsley & MacSwain(1), bees of the genus Diadasia...like those Ron found associated with this ripiphorid...are positively recorded as hosts for R. diadasiae while the host for R. sexdens was given as "unknown".

… Aaron Schusteff, 23 January, 2013 - 9:14pm

Thanks, John.

That's what I'd thought, too. BTW, I have some interesting bee posts in the works.

… Ron Hemberger, 9 June, 2010 - 11:16pm

I look forward to the bee posts

what bees were nesting in the area where you found this beetle?

Diadasia?

… John S. Ascher, 9 June, 2010 - 11:38pm

Several kinds

What I'm fairly sure are Diadasia were about twenty feet away. (Perhaps these are mallow visitors, as were those last year at Nix.) There were also bees nestled in bindweed, similar to the way they are in coyote gourd blooms.

… Ron Hemberger, 9 June, 2010 - 11:59pm

That's good extra info

According to references (e.g. Linsley & MacSwain(1)) males frequent nesting sites of hosts...presumably looking for newly emerged females. Also, bindweed is in the Convolvulaceae, which is another family that, like Malvaceae, has specialist Diadasia pollinators...according to this reference.

… Aaron Schusteff, 25 August, 2012 - 11:39pm