Bess Beetles

Bess Beetles (Odontotaenius disjunctus)  in the family Passalidae are one of almost 500 species within this family of beetles. They are found from the Central United States and eastward. Most beetles within this family are found in the tropics, with only a few found within the United States. This particular species goes by many different common names including Peg Beetle, Betsy Beetle, Bess Bug, Patent Leather Beetle, and Horned Passalus. They grow quite large at over an inch in length, and with that horn on their face they can look very intimidating, but they are not known to bite.

These beetles are fond of old rotting stumps, and logs where they feed on the decaying wood. The boring or tunneling action they perform will create chambers where they will mate, lay eggs and rear young. 

These beetles have a unique life cycle, the female will lay eggs within rotting stumps or other decaying wood. Both adults will care for the young larvae. They feed their offspring bits of chewed up wood. It takes up to one year for them to complete their life cycle to adulthood. It is not uncommon for the adults to consume injured larvae.

(Bess Beetle Grub)

 (Bess Beetle Pupa)

 Both adults and larva are capable of making squeaky noises through stridulation, by rubbing their abdomen against their wings. This is a form of communication between adults. If handled they may stridulate loudly.

The newly emerged adults look different from mature adults in that they are reddish-brown in color instead of glossy black. As they age they will begin to look like black patent leather, which is where the common name of patent-leather beetle comes from. They often live in colonies within stumps,and seem to prefer oak, maple and other deciduous trees. The stump where I find them is from an old silver maple that died many years ago. The remnants of that stump have attracted many forms of wildlife from beetles, cockroaches, horntails, and snakes to name just a few of the things I've encountered while exploring. Logs and stumps where these beetles are active will decay rapidly, and nourish the soil with important nutrients. This activity is considered beneficial to humans by providing the necessary nutrients that trees and other plants need to thrive.  Many people would excavated and grind out an old stump. I prefer to leave them and see what shows up.

 

To learn more details about this beetle and their range be sure to check out this link for the University of Florida and their information page on this beetle. I am proud to say my image of the pupa is featured there.