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For Insects, Spiders & Their Kin
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Photo#52285
New smallest beetle! - Bacanius punctiformis

New smallest beetle! - Bacanius punctiformis
Nashua, Hillsborough County, New Hampshire, USA
May 14, 2006
Size: approx. .676 - .804 mm

Images of this individual: tag all
New smallest beetle! - Bacanius punctiformis New smallest beetle! - Bacanius punctiformis New smallest beetle! - Bacanius punctiformis New smallest beetle! - Bacanius punctiformis New smallest beetle! - Bacanius punctiformis New smallest beetle! - Bacanius punctiformis New smallest beetle! - Bacanius punctiformis New smallest beetle! - Bacanius punctiformis New smallest beetle! - Bacanius punctiformis New smallest beetle, plus mites! - Bacanius punctiformis New smallest beetle, plus mites! - Bacanius punctiformis New smallest beetle, plus mites! - Bacanius punctiformis New smallest beetle, plus mites! - Bacanius punctiformis

Histeridae: Bacanius punctiformis
Painful working through the key, but this looks to be correct. Not known from New England, but we have a nice series from Oklahoma that match up with your specimen quite well.

 
Thank you tremendously
for taking the time to key this out.

Well, it's known from New England now. I guess this is a state and regional record.

This beetle was taken from shelf fungus found in a wooded area along a railroad spur that crosses Charron Avenue in Nashua. I still have a bag full of broken peices of the shelf fungi I collected that day if anyone would like to try finding another one

 
Baccanius
You can add Vermont to the list of areas this occurs. Back in 2004 in the spring along the Winooski R. in Washington Co. I kept coming up with these little Histerids under a log along the riverbank. Two spp. actually, because some had very narrow protibia(Aeletes), and the many other with very thickened protibia(??until now). Day after day found these 2 spp under this log(I assumed at the time in spring mating). Your images and discussion here has helped me to ID this. I have 30+ in alchohol from that period. Thanks. I'll post one soon.

 
Excellent, Richard!
I look forward to seeing yours. Your data will appear automatically on the map when you post your images. Maybe you'll succeed in getting better detail than I was able to capture.

I think these beetles have been around for awhile but have just been undercollected because the few mite collectors are uninterested in beetles and the beetle collectors think they're looking at mites. I'm not sure exactly what that implies about you and me ;-)

 
polypore fungi
and under bark are mentioned as sites where this species has been collected in the book on the beetles of the Northeast (Downie and Arnett). Closest known state/provices are New York and southewestern Quebec. Thanks for sending it to me. While it took awhile, it is a valuable addition to the collection.

Histeridae: Aeletes politus
Fairly common, not often observed.

 
A. politus Guide page reference really A. simplex?
Downie and Arnett list 2 Aeletes sp. for the northeast. A. simplex is described as "Dorsum finely, sparsely punctate." and A. politus - impunctate. Jim's and Tom's both appear impunctate. But the photos on the A. politus guide page internet reference http://www.chebucto.ns.ca/environment/NHR/Aeletes_politus.html appear like the specimen might be "finely, sparsely punctate". Any thoughts?
Wonderful detailed little creatures in any case:)

 
I did look again.
Even through my 25x macroscope I can't see a great deal of detail. The elytra are definitely striated, although the stria appear confused. I thought I could see fine, even, sparse punctuation on the very shiny pronotum as well as in the elytral stria.

 
Great points,
although if mine were finely and sparsely puntuate, I don't think it would be obvious due to the limits of my lens. Maybe I should pickle the little guy and put him under the 25x macroscope so I can report in more detail.

 
I note differences.
Tom Murray's Aeletes politus looks like a different species from mine.
The base of the antenna on Tom's is very delicate whereas mine is comparatively thick. Nor does the pygidium come to nearly the point on mine that it does on Tom's. One that looks more like mine is this image of Aeletes (Acritinus) floridae (Marseul, 1862). I'm not saying I think this one is that species, but it has not only the thicker antennal base but a slight wrinkled striation-like texture on the elytra that is visible in one of my photos. What I am suggesting is that either mine or Tom's might not be A. politus.

btw, I note this genus is given as Aeletus rather than Aeletes on the UNH site.

 
I agree
it is different, but can't figure out what it is. Save them for me. It is not A. floridae, but ....???? You commented on how thick the protibiae are, while Aeletes has narrow protibiae. Tom's images are Aeletes. I will change the UNH database from Aeletus, but the change won't turn up online for some time.

 
New images posted.
I took a bunch of photos of this beetle with mites before introducing it to the adult beverage so Don can key it in hand. The new photos might also help place it to species as they capture a bit more detail collectively.

 
Moved back to family
I might have collected just one. It's very possible the others that I thought were mi*tes ARE mi*tes. I have since photographed the species of mi*te I thought this one was and will link a thumbnail here when I post those pix. The tiny histerid is in a deli container with a few scraps of shelf fungus and some other beetles. If he hasn't escaped or become snackfood for something else, he's yours.