small clown beetle - Plegaderus sayi

Plegaderus sayi

confirmed, and I am indeed happy to have it.

… Donald S. Chandler, 21 February, 2008 - 11:25am

New record for NH

At least it is not on the UNH checklist. Don Chandler will no doubt appreciate receiving the specimen if it is available.

… Jim McClarin, 29 September, 2007 - 5:14am

I'll dig this one out for Don

Who knows how many different small bugs are there, but haven't been collected in the state and identified.

… tom murray, 29 September, 2007 - 7:28am

Your images of this genus

make it look a great deal more unusual than mine. I think my present flash boost technique was not yet developed at the time. I'd like to be able to compare more closely to see whether they are different species. I'm pretty sure I didn't save the specimen though.

… Jim McClarin, 28 September, 2007 - 5:46pm

Jim,

Your's looks like it has wrinkles in the top of the elytra. Maybe you have the other species from the northeast.

… tom murray, 28 September, 2007 - 7:32pm

If strigose means what I think it does,

then I'd say you're right, Tom. I think I'll place it there.

… Jim McClarin, 29 September, 2007 - 5:03am

Thanks Tim

I didn't think this one would get to species, but the limited choices up here made it possible for you to figure it out.

… tom murray, 28 September, 2007 - 7:39am

Thanks Boris

It sounds like these are difficult to place to species.

… tom murray, 27 September, 2007 - 8:36am

only 2

while there's about 14 from NAmer, Downie and Arnett list only 2 from the Northeast:
P. transverus Say - Elytra with strigose, confluent punctures.
P. sayi Marseul - Elytra with sparse round punctures, some discal ones tending to coalesce longitudinally.

So while I've never seen either of these, it looks to me like yours should be P. sayi. Jim's I'm less sure of. His seems to be a mix of "discal longitudinal coalescence" and simply "confluent punctures".

… Tim Moyer, 27 September, 2007 - 10:27pm

Awesome image.

I agree with Plegaderus sayi.

Another possibility would have been Plegaderus confusus, which was described by Bousquet and Laplante in 1999 in the Histeridae of Quebec (Les Coleopteres Histerides du Quebec, treatment is in French) and looks a lot like sayi. In their 2006 treatment of the Canadian Histeridae (Part 24 of The Insects and Arachnids of Canada, in English and French and highly, highly recommended for histerid identification in your neck of the woods), these species are separated by:

sayi - Lateral lobe of pronotum wider (4 or 5 rows of punctures at level of transverse groove) and elytral disc relatively flat

confusus - Lateral lobe of pronotum narrower (3 rows of punctures at level of transverse groove) and elytral disc rather convex

In their 2006 treatment, the authors state they have seen specimens of both species from New Hampshire.

Considering how difficult it is to photograph histerids, I am amazed that I can see at least 4 rows of punctures at the level of the transverse groove of the pronotum. Keep up the great work.

… Jeff Gruber, 30 September, 2007 - 8:12pm

genus is easy:

Plegaderus

… Boris Büche, 27 September, 2007 - 8:20am