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Click Beetle - Lacon marmoratus

Click Beetle - Lacon marmoratus
Geneseo, Henry County, Illinois, USA
May 25, 2005
I photographed this click beetle today and noticed what appears to be little hitch hiking mites right near the head and tail end of the beetle. Am I correct in this assumption? I didn't notice them until I downloaded the photo, so I enlarged the picture for sake of seeing them. Any comments?

Moved, must be L. marmoratus
Moved from Lacon.

Danosoma obtecta, i believe
often referred to as Lacon (Danosoma) obtecta, but treated separately in the guide

The pattern of scales is wron
The pattern of scales is wrong for Danosoma obtecta.

Click beetle.
This is a species of Lacon, one of the few easily recognizable genera of Elateridae:-) The heavy coating of scales, and the overall resemblance to tree bark help ID them.

That's what I originally thought, but the grey color threw me off a bit. All of the others that I have seen appear to be more brown in overall color. Thanks for the ID.


I think you're probably right. The hitch-hiking practice is called phoresy, and mites that do it are termed phoretic mites. It's a means of dispersal for them, as they get taken places they couldn't go by themselves. I read somewhere that it's not necessarily a totally free ride: while they're riding, the mites may clean bacteria and parasitic fly eggs etc. off the surface, so the beetle might benefit from that (don't know if that's the case but it sounds plausible).
The pattern on the beetle looks interesting; hopefully someone can ID this one.

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