Sunday, August 9, 2009

Danosoma

Species of the click beetle genus Danosoma can be easily misplaced in the genus Lacon. Both genera contain species with colorful scales and look similar in their general appearance. The reason why they are placed in a different group is because Danosoma lack a defining seta at the base of the tarsal claws. This can be confusing to locate (since there are other setae on the tarsae) and becuase the claws are small (at least they are if there is not adequate magnification) so be careful wih your id's.

Here are pictures of the two American species D. obtectus and D. brevicornis. They both have a diagnostic groove down the middle of the pronotum but D. brevicornis also has a couple of round impressions(on each side of the groove). Danosoma obtectus is a bit narrower and lacks the impressions.

Geographically, D. brevicornis occurs in the northern parts of the US and into Canada (essentially coast to coast), whereas, D. obtectus occurs in the Northeast US and adjacent areas in Canada.