Life in a Log



Flat headed Borer Grub

While chopping wood at Owls' Knob, John came across this strange grub. This long grub is a flat headed borer and will go through a complete metamorphosis this season, emerging in summer as a beautiful beetle. Butterflies are not the only insect to that goes through a complete metamorphosis, beetles also start out as a larva, pupate, and come out a completely different creature. Like most beetles, this bug spends most of its life in this larva stage where it plays an important roll as a decomposer. Some borers kill living trees and can be pests to a forest. However, this borer perverse dead wood, so it is not a threat to live trees. This decomposer help break down wood and recycle it into fertile soil. It is also a prized find for any bird and sought after by all woodpeckers.

Left: Bess Beetle--Right: Flat headed Borer...no relation

Soon after discovering the flat headed borer, John discovered a black beetle. Like many insects that live through winter, beetles turn the water in their bodies into glycerin which acts like an antifreeze so they don't freeze solid in winter. Therefore, this beetle moved as if in slow motion. I spent all day trying to identify this beetle. There are more beetles species than an other creature on earth, over a estimated 350,000! Many species are likely still undiscovered. Upon first glance I thought this was a stag beetle but they are only found in their adult form during summer. Then I guessed species of ground beetle, but its furry legs, distinct face, and unique antennae told me otherwise. Finally I identified it as a Bess beetle (Odontotaenius disjunctus).

Bess beetles live in communities inside logs and communicate using over 14 different clicks, squeaks, and kissing sounds. Because insects do not have voices, all these sounds are made by rubbing their wings against their abdomen. Larva also makes sounds by rubbing their tiny legs against their soft bodies.
In most cases, insects lay eggs and never wait around for the larva to hatch. However, Bess beetles not only wait for the eggs to hatch but they feed their young, protect the larva, and stay with them as they pupate and go through a complete metamorphosis. Both male and female Bess beetles care for their young, feeding them premasticated wood. In the insect world it is almost unheard of for males to tend to their young, in fact, it only occurs in one other beetle species and in termites.

Bess Beetle (Odontotaenius disjunctus)

Like the grub above, the Bess beetle eats wood; it is a decomposer. Among all the categories in the food chain, I believe that decomposers are the most overlooked. Of course it is easy to see that plants are producers and animals are consumers but the decomposition process is rarely praised even though it is at the foundation of all life. When people think about decomposers they usually think of slimy fungi and icky grubs. The shinny black beetle with its complex social structure, language, and upstanding parental skills does not often come to mind.
 If it weren't for decomposers we would be up to our ears in rotting goo. Luckily, the earth recycles everything in a beautiful and efficient way; and the decomposers that we can thank for this are not as gross as you might have originally thought.