Dung Beetle

I was preparing to dip some water from one of my rain barrels when I found this beetle floating inside.  It appeared dead, but its legs moved when I plucked it from the water and it became more animated as it dried.  This beautiful beetle, Dichotomius carolinus, largest of the local Dung Beetles, was cause enough to take a break from my work to examine this magnificent specimen.

The beetle at first appeared to be adorned with pale stripes.  Closer examination revealed the stripes to actually be soil caked into grooves on the wing covers.  Dung Beetle larvae develop in the ground at the bottom of a deep burrow where they feed on a supply of dung placed there by the adult beetle.  The beetles can accumulate soil on their bodies when digging nest burrows or when burrowing out of the soil after pupation.

This is one tough beetle.  It measures just an inch or a little better, but feels like a stone resting in the palm of your hand.  If you try to hold it in a closed fist, it will use its strong front legs to force your fingers apart.  The photo shows the pose the beetle adopts when it begins digging.  Front legs try to force the soil sideways while the scoop shaped head forces lose material up and away.

All six legs are designed for digging and scooping.  Dung beetles feed on manure produced by large mammals, primarily domestic cattle and horses.  Their actions in a pasture situation are considered beneficial to the plants and soil because of the burrows and incorporation of manure into the soil profile.  Livestock also benefit by the rapid reduction of concentrated manure which results in fewer pests and parasites surviving within the manure piles.  Several exotic species of Dung Beetles have been intentionally introduced into the United States in an attempt to maximize the benefits of this group of insects.

Dichotomius carolinus is a native species and is typically not the most abundant Dung Beetle species in an area.  Most dung beetle research concentrates on grassland areas dominated by domesticated livestock, so the beetles are interacting with non-native species.  I wonder if this Dung Beetle species utilizes manure from the Whitetail Deer?  I’m sure they would have used manure from Bison, but Bison were extirpated from Ohio over 200 years ago.  The deer is the largest free ranging native ruminant in this area and hopefully produces a large enough concentration of manure to satisfy this particular Dung Beetle.  I may have to set up a couple of deer manure traps and see what shows up.

I found this neat mite living on the beetle’s body.  I’m not sure if it is actually a parasite or if it is just hitching a ride.  Each individual manure drop supports its own special ecosystem in which myriad species feed upon the manure and each other.  Some species are able to move from one manure source to another on their own power.  Species with limited mobility often use the more mobile species as transportation to fresh manure.

The mites preferred lodging was beneath the head near the attachment of the front legs.  That’s where it was when I set the beetle free.  Hopefully, both beetle and passenger found their way to fresh manure.