Unknown Blister Beetle

Gunmetal-colored blister beetle?
Location: Albemarle County, Virginia
July 20, 2011 3:36 pm
Found this on a grapevine. Gorgeous matte gunmetal coloring. Guessing its a blister beetle but unsure.
Signature: Karl Hambsch

Blister Beetle

Hi Karl,
We concur with your guess that this is a Blister Beetle, and furthermore, we believe it is in the genus
Epicauta based on the information provided on BugGuide, but the species identification is proving to be elusive.  Numerous species in the genus Epicauta are gray in color, and there seems to be some variation in the tone within the species as well as overlap between the species.  If you browse the genus Epicauta on BugGuide, you will see our quandary, especially since there are also subgenera to consider.  You may try submitting your images to BugGuide and have the Blister Beetle expert Dr. Pinto take a stab at a species identification.  Here are the guidelines posted on BugGuide for the types of details he likes to see in field photos to maximize the chances of a proper species identification:  “There is no general recipe. For species ID of some we need to see palpi; for others its tibial spurs; for others it may be hind coxae. For the Caviceps Group the head capsule may be important. These features are not easily documented in field photos. In general, for the subgenus Macrobasis which includes many southwestern species we should have males. Males for all groups are generally best unless the species has a unique color pattern or a unique shape. Fortunately genitalia are of little to no use in Epicauta. Many common Epicauta are simply difficult to identify from photogarphs – field photos are poor substitutes for having a specimen in hand. It seems that it would eventually be worthwhile to photograph authoritatively identified material in museums – virtually all the US species of Epicauta could be done rather easily. Field photos seem to be an inefficient way to get our fauna documented for the non-specialist.”

Blister Beetle

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