This tiny beetle may not look noteworthy but it sure has made a name for itself. Or rather, various people have made many names for it. 

The genus Agathidium contains over 100 species of “slime-mold beetles” in North and Central America. They’re called that because both the larvae and the adults eat slime molds. Slime molds, by the way, are a diverse and sometimes beautiful group of organisms that are neither plant, animal, nor fungus… look them up!

This beetle is also known as a “winter wood beetle,” because it lives through the winter as an adult, often under bark. Yet a third common name is “round fungus beetle.” That’s because they can roll themselves into a ball, like an isopod. They can even tuck in their antennae and their legs! As you can see, the extra-wide thorax covers the insect’s sides like a shield. 

Now for the uncommon names: A couple of researchers from Cornell (Wheeler and Miller) did a deep study of the genus in the mid-2000’s, uncovered about 65 Agathidium species that had not been named, and gave them names. The ones that got the most press were A. bushi, A cheneyi, and A. rumsfeldi, after three members of the administration at the time, and A. vaderi after Darth Vader. Quentin Wheeler said his favorite name was A. gallititillo, a name that combines the Latin words for “French” and “tickle.” 

Notably, there’s one named A. oregonese that was found near Mount Hood, and Miller and Wheeler said more species are likely waiting to be discovered in the coastal forests of the Pacific Northwest. 

Stay curious!

See more of Karen’s work here.


Excellent 2005 paper by the scientists who gave many species their names: Accessed 12/6/22.

A nice profile of the genus from the U.K.: Accessed 12/6/22.