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Anisodactylus? - Anisodactylus dulcicollis - male

Anisodactylus? - Anisodactylus dulcicollis - Male
1-35 frontage road just south of Dallas, Dallas County, Texas, USA
June 29, 2014
Size: 11 mm
I tentatively identified this specimen as Anisodactylus opaculus, but would appreciate further input.

Specimen was found in a parking lot, under lights at night.



Moved from Ground Beetles.

"Anisodactylus dulcicollis" is superficially a better fit
than "A. opaculus" in my opinion based on shape of pronotum and proportionately small head. Both species require trifid-shaped protibial spur (hidden from view here), hence subgenus "Gynandrotarsus". Best species key for this subgenus is by Noonan (1973:357-358). Otherwise, there are at least 16 species of Anisodactylus known in TX.

Agreed - thanks!
Upon further inspection of the specimen, and more closely reading the key in Noonan, I believe you may be correct. The one thing that throws me off is the specimen is very dull - I have other specimens of A. dulcicollis and all are much shinier.

Further traits include the specimen lacks a ridge on the clypeus, and the first segment of the foretarsus is only slightly expanded (not overlapping segment II).

Anisodactylus dulcicollis vs haplomus
Clarification of the protarsal distinction by Noonan: The only slightly expanded protarsomere #1 in A. dulcicollis vs much more expanded of same in A. haplomus applies to females only. That distinction does not transfer well to the males.

I've occasionally experienced specimens that appear more dull than they ought to be due to age with excessive wear or possibly due to prolonged exposure to potentially corrosive chemicals (say antifreeze in pitfalls). Usually high power inspection of the actual reflection and structure of the microsculpture will see past the artifacts. I noticed a gooey residue(?) atop your imaged specimen. What is that and could that be changing the true luster?

Jesse, your profile says interest in Carabidae. Please actively continue with that - especially for the California caraboid fauna which remain a mystery taxonomically for most of us. I look forward to your continued identifications of the California ground beetles. Some day we should arrange a swap for my Wisconsin duplicates. Alternatively, I accept any caraboid specimen donation for the purpose of accurate species determination and/or photo-vouchering.

Not sure how I misread the tarsomere couplet. For some reason I thought it said male.

The residue you can see is actually a little liquid ethyl acetate.

Feel free to send me an email anytime to discuss an exchange, or just talk beetles - my address can be found in my profile.

Anisodactylus a possibility
please crop off the empty background, move the phrase "parking lot lights at night" to the Remarks field, and make sure there is no period at the end of text in the City field (unless the last word is an abbreviation)