Category Archives: Hister Beetle

No Clowning Around in the Pool Without a Life Jacket.

Yesterday I was the lifeguard. And, I had swimmers needing saving!

Hister Beetle (Genus Margarinotus I believe) – April 7, 2022 San Juan Island, WA

Here’s one of the species I used a piece of cardboard to rescue from drowning. This is a beetle in the family Histeridae, also known as a Clown Beetle. I told him no more clowning around without a life jacket. 🤣 Watch as it wrings its hindwings out, rolling them in under the leathery elytra (the outer wings).

I believe this beetle is in the genus Margarinotus. For ID beyond this, I’d need more time and a lot of patience. However, I can tell you I’ve learned some species of Hister beetles are associated with the nests of rodents, birds, and even ants and termites. They are pest predators, meaning they eat other insects at all life stages. They also are especially adept predators of fly eggs. You can often find them in leaf litter, dung, carrion, and under tree bark, or living in those ant mounds where they may be fed by ants, eat the leftovers the ants discard, or in some cases, they eat the ants!

Some other curious tidbits about these beetles include their acting ability. They play dead (Thanatosis) to deter predators. The word Hister is derived from Latin and means “Actor.”

Hister Beetle (I believe Margarinotus sp) – San Juan Island, WA

References:

Caterino, M. S. (2010). A review of California Margarinotus Marseul (Coleoptera: Histeridae: Histerinae: Histerini), with descriptions of two new species. The Coleopterists Bulletin, 64(1), 1-12. https://bioone.org/journals/The-Coleopterists-Bulletin/volume-64/issue-1/0010-065X-64.1.1/A-Review-of-California-Margarinotus-Marseul-Coleoptera–Histeridae/10.1649/0010-065X-64.1.1.pdf?casa_token=FFQE6VfrPhwAAAAA:6hS4kWWWX-lGeUPQFiU-7Dc2atg_nhsgP0almrxzvWjgwhxDLMShzekiAS7HWEKT5_AL2n4i

Wenzel, R. L. (1960). Three new histerid beetles from the Pacific Northwest, with records and synonymies of additional species (Coleoptera: Histeridae). https://www.biodiversitylibrary.org/page/2847194