Burying Beetle with Mites

bugman

August 10th, 2009 at 10:12 am

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What is this flying black bug with orange spots?
August 10, 2009
I’ve never seen a bug quite like this one, it flew into my house, and ended up landing on a washcloth, where I was able to get a picture. It was covered in tiny spiders so as soon as I got the picture I put the bug and the washcloth outside, but I’m still curious as to what it was exactly. It was 1-2 inches long, definitely had wings and three pairs of legs. Its antennae and legs were furry.
Thanks
Enumclaw, Washington

Sexton Beetle with Phoretic Mites

This is a Burying Beetle or Sexton Beetle in the genus Nicrophorus, but we cannot tell you the exact species. None of the examples posted to BugGuide illustrate four distinct red spots in a row across the elytra or wing covers. The Burying Beetle was transporting Mites, not spiders. The Mites use the Burying Beetle to travel from location to location, a phenomenon known as phoresy, in order to take advantage of flight to access a new food source. Burying Beetles will bury small dead creatures like birds or mice and lay eggs on the carcass. The young feed on the rotting flesh. The Mites feed on fly eggs and maggots, so phoresy is mutually advantageous to the Mites and the Burying Beetles. The Mites get a food source and the Burying Beetle benefits because more rotting flesh is available to its progeny. We will see if Eric Eaton can assist us in an exact species identification.

Update from Eric Eaton
Daniel:
I’m pretty sure this is just a variation of the sexton beetle Nicrophorus defodiens. It is highly variable in its markings, as evidenced by the individual specimens in the image gallery here:
http://collections2.eeb.uconn.edu/nicroweb/hatchabs/index.htm
I know I have seen very similar specimens from northwest Oregon, too.
Eric