Subject: Beetle with Mite Infestation
Location: Wheatland, IN
June 19, 2012 2:37 pm
I found this bug in the grass of my in-laws farm in Wheatland, IN. This photo was taken May 12th (warm and humid). Not too sure what kind of beetle this is, or what type of little bug is infesting it. We let the beetle go about his business, but he seemed worse for the wear. Kept trying to fly off, but his wings seemed to be crinkled up and he couldn’t straighten them. He finally rolled over and laid there for awhile. Came back later and he was gone.
Any info is appreciated. Thanks!
Signature: Mountain Mama
Dear Mountain Mama,
These are photos of a Dung Beetle, a group of Scarab Beetles in the subfamily Scarabaeinae (see BugGuide) that collect fresh animal excrement and roll it in a ball prior to burying it and laying an egg. We are uncertain of the species. The dung is the food source for the hatched larva. Dung Beetles are especially common in areas where there is livestock and Dung Beetles help the decomposition process that returns nutrients and minerals back into the soil in a usable form. The crumpled wings you mentioned are actually the flight wings of the beetle. The first set of wings, called the ELYTRA are hardened and they protect the flight wings that are folded while the beetle is at rest. Though the Dung Beetle did not go airborne while you were watching, your photo does not indicate that there is any physical problem. Your photo is a perfect photo to illustrate the vocabulary word ELYTRA. Originally we were going to use your submission to illustrate PHORESY, but there are a dearth of good images on our site showing a beetle in flight, so we changed our minds at the eleventh hour. This image of an Eyed Elater from our archives is also a nice illustration of the ELYTRA.
The mites on the underside of the Dung Beetle are most likely Phoretic Mites, meaning that they do not parasitize the beetle, but rather use the beetle as a means of transportation. Phoresy is a term used for hitchhiking on another species. By hitching a ride on a flying species, the mites are able to be transported to a new food supply.