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Stenhomalus? - Stenhomalus taiwanus

Stenhomalus? - Stenhomalus taiwanus
Montgomery, Montgomery County, Alabama, USA
July 28, 2012
Size: 4mm
I initially thought this was a dark colored Obrium maculatum when I caught it. Looking at it more closely the pronotum is shaped differently than O. maculatum and it is covered in erect AND decumbent hairs, not just erect hairs like O. maculatum. The only other possibilities for AL could be O. rufulum (which I have seen specimens) or O. rubidum (listed for "eastern US"), but from specimens/photos I've seen neither of these are marked. Any help with an ID would be greatly appreciated.

got one at my deck lights the other night in Brazos Co., TX
didn't pay any attention to it at first because O. maculatum is so common in my backyard; glad i did snatch it, 'cuz we were thru the second 12-pack by the time the beast landed on the wall under the light... no matter what, i keep my aspirator handy

hope i see and collect more --not that the spreading of yet another adventive species is something to feel happy about

got another specimen ~8 mi to the south of that location
so it's definitely out there, and probably widespread

Thanks for posting, V. It has
Thanks for posting, V. It has also recently turned up in another Alabama county (Blount Co.).

glad you find it helpful, Brian
i'm pretty excited to see funny things turn up...

an interesting detail, though, is that at my rented backyard back in May there were lots of Obrium to filter out, but now at this new place there are none


Moved from Longhorned Beetles.

Second collection
I have made a second collection of this species at the same location.

sweet... in a perverted kind of way :]

I've been doing some digging
I've been doing some digging around. Could this be the Asian species Stenhomalus taiwanus?

Check out
Stenhomalus cleroides Bates. It also is very similar.

Ran them through The Obriini
Ran them through The Obriini of the Japanese Empire (Coleopt., Cerambycidae) by Gressitt earlier and got them to the two. Based on the couplet these would be S. cleroides.

Prothorax broader at apex than base......... cleroides
Prothorax not broader at apex than base..... taiwanus

I believe you can tell this from the photos posted. Gressitt also states "S. taiwanus would seem to be at the most but a variety of cleroides...". This is an older paper (1935) and was wondering if there was anything more current.

you have now collected two of these (at the same locality I presume) it is obvious that they are emerging (or are established) close by. What is in the immediate vicinity that might be the source? Any warehouses with solid wood packing material? Plant nurseries with exotic plants (imported bonsai plants have been the source of some cerambycid introductions). Anything that seems suspicious?

Both were collected at the sa
Both were collected at the same location - my home in the historic Capitol Heights area of Montgomery which is approximately 2 miles from downtown. There are no warehouses/nurseries/etc. in the immediate area. The closest possibility that I can tell is over 1.5 miles away. I'm a biologist with the DCNR Heritage Section and I've been working on a state bycid list for a couple of years now. When I figured out it was an Asian species I feared it could be invasive and possibly established. The only info I could find on the internet for Stenhomalus in the US was an article which reported Customs and Border Protection intercepting Stenhomalus (species not given) in Baltimore in 2009 and previously in 2005. Both were found in shipping containers from China which were subsequently fumigated. I also tried finding recorded host plants for S. cleroides but found nothing. Some hosts listed for other species of Stenhomalus include Rhamnus, Euonymus, Zanthoxylum - all of which we have. I was hoping to find some literature and publish this finding as a Note (probably in the Coleopterists Bulletin) before publishing my state list (which includes approximately 50 state records).

Stenhomalus outcome
Howdy from up north. I was just curious whatever came of your Stenhomalus find? We had a run in with Stenhomalus as well in VT on a shipment of baskets from China but couldn't really find much info on it. Was interested to see that you found it, presumably established, in Alabama. Has it been studied or looked at in the local environment? What is it feeding on?

Thanks for your post; this really helped us in IDing the intereception up here.

Rhonda Mace
Berlin, VT

Hi Rhonda, I sent a few sp
Hi Rhonda,

I sent a few specimens off to get ID confirmation on. The specimens were examined by Dr. Steven Lingafelter and he identified them as Stenhomalus taiwanus. The known host for S. taiwanus in Asia is Zanthoxylum sp. It doesn't seem to be obligated to a single species. Unfortunatly there are a couple/few species of native Zanthoxylum in the eastern US (2 in AL). Although it hasn't been observed on Zanthoxylum here (only collected at light), I have several collections from 2009-2012 from different counties in two states. This suggests to me that it is establish (or I've been extremely "lucky"). I'm in the process of writing it up now. If you have any other questions feel free to contact me via email (address on profile page).

great; glad Rhonda asked!
Brian, once your paper has been published, pls let us know so we can update the guide pages with proper ref citation

Will do, -V-. BTW, I think St
Will do, -V-. BTW, I think Stenhomalus has been placed in its own tribe (Stenhomalini).

thanks, Brian.
some move it to Stenhomalini, others keep treating in the Obriini... i was just trying to figure out which arrangement better fits the Guide when i saw you comment
but if you prefer having it in its own tribe, i will oblige, albeit a bit reluctantly: having two tribes with a single genus each kinda... defies the purpose )))))))))
as long as you are on top of things here, would you please supply me with a general info for the genus page (global # of spp., geo distribution, and such)? would be terrific.

I don't see how that could be any of the known eastern U.S. species, nor does it seem to be any of the western U.S. species. It does bear some resemblance to some of the Neotropical species. I will pass your picture on to some people more familiar with that fauna and see if we can get a name on it. It goes without saying that more specimens would be great.

Thanks Mike. I had checked it
Thanks Mike. I had checked it against photos in "A Photographic Catalog of the Cerambycidae of the World" and didn't find a match I was comfortable with. It was collected at my back porchlight approximately 2 miles from downtown Montgomery, AL.

Moved for expert attention
Moved from ID Request.

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