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Photo#114785
Hydrophilidae? - Copelatus glyphicus

Hydrophilidae? - Copelatus glyphicus
Houston, Harris County, Texas, USA
May 1, 2007
Size: ~6 mm

Images of this individual: tag all
Hydrophilidae? - Copelatus glyphicus Hydrophilidae? - Copelatus glyphicus

Moved

Moved
Moved from Copelatus.

C. distinctus
Keyed from Larson et al. (2001)
Notes: 10 striae on each elytron, length greater than 5.5 mm, range includes TX, AZ, and Mexico

 
Copelatus glyphicus
I suppose that this is a rather large Copelatus glyphicus. C. distinctus is a much more elongate species with finer (sometimes broken) elytral striae, and the sutural interstices (between suture and innermost striae) are not markedly widened towards the elytral base (in C. glyphicus the innermost striae are diverging towards the base). The male genitalia of C. glyphicus, as figured by Larson et al. (2000), are very distinctive. The male genitalia of C. distinctus are completely different and have been illustrated by

YOUNG, F.N. (1963). The Nearctic species of Copelatus ERICHSON (Coleoptera: Dytiscidae). Quarterly Journal of Florida Academy of Science 26: 56–77.

 
gradual widening?
so I gather from this and some of our other C. glyphicus that the widening of the sutural interstices is rather gradual, starting around the apical third and barely doubling by the base? I can't really tell on the only other image we have currently placed under C. distinctus, but perhaps the interstices is fairly constant.

Thanks,
Tim

 
yes, it is a gradual widening
Hi Tim,

you did a very well suited description of the item! The other bugguide image placed under C. distinctus is really that species, but you are right, the inner striae are difficult to trace on that photo. The same is true for another photo found on http://insects.oeb.harvard.edu/mcz/Species_record.php?id=15216, under the synonym C. impressicollis. However, once I took a photo from a specimen (no type material) deposited at the Bavarian State Collection in Munich which may be downloaded and integrated in bugguide from my webspace: http://hollimnicinsects.org/DYT.Copelatus-distinctus(cof)HabVar(WoSo-ZSM).jpg. In this specimen and in others which I have seen in the Natural History Museum, London, the inner striae are almost parallel within the basal 2/3 of elytra.

Best regards, Wolfram

 
species page added
*

 
Thanks
tim and tim.

Thanks
for the genus ID, Tim.

Moved

Predacious diving beetle
Family Dytiscidae. Lacks the clubbed antennae of Hydro*philidae.

 
Genus Copelatus
appears to be Genus Copelatus - elytra stria + size make that the only choice I know.

 
Thanks
Thanks for the correction.