Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Dactylosternum? - Dactylosternum abdominale

Dactylosternum? - Dactylosternum abdominale
Lancaster County, Pennsylvania, USA
October 13, 2013
Size: 5mm
First hydrophilid I have ever seen in compost.

Images of this individual: tag all
Dactylosternum? - Dactylosternum abdominale Dactylosternum? - Dactylosternum abdominale

Moved tentatively
Moved from ID Request.

sure looks like one. Not sure of any records that far north though!

cool; a good ventral, pleease?
what you said about compost is surprising; Cercyon & kin should be quite common in these situations

I've never seen any before. I see a lot of Cercyon at lights, but never in their natural habitats. The same goes for most of the water beetles I find (Elmids, dytiscids, hydrophilids, gyrinids, haliplids, etc.)

I suppose it is Dactylosternum abdominale...
although I have no reference specimen to check against. It does seem to be consistent with the description. Hopefully Tim will chime in...

Dactylosternum abdominale is the only species in the genus found in the Nearctic with elytral striae, and is recorded from CA, TX, AL, and FL by Smetana (1). It is also a tramp species, so I guess its not terribly surprising to find it further north occasionally. The species is said to be found in damp situations, often associated with rotting vegetation.

I agree that this is [i]D. ab
I agree that this is D. abdominale though I too, do not have any reference material to compare this to. Although this is a significant range extension, it is indeed not surprising given that it has been 35 years or so since Smetana's report on the species. With widespread commerce and improved means of transportation (plus the beetle's habitat preferences), 35 years is plenty of time for a non-native insect to spread far and wide.

Ciegler (2003)
in her treatment of the SC fauna, indicated this species is known from NC.