Old wooden beam affected by woodworm. Wood-eating larvae species beetle

The tunnels eaten out by termites help break down the wood and allow other organisms easier access to the wood -- jumpstarting the wood recycling that eventually feeds the next generation of plants.

There it was, autumn’s herald, weakly struggling in the late-afternoon air. Just as certain arriving birds signal the start of spring, swarming termites are a sign of fall.

Feeble fliers, queen and king termites drift in the wind until striking land, tree, or some other object. The queens drop their wings then walk until they locate a suitable nest site. The kings follow them, one king eventually setting up house with each new queen.

After beginning the "termitarium" and mating, the queen will lay 10 to 15 eggs, which she and the king will nurture until their offspring are old enough to help support the colony. Once the first generation is mature enough to assist with the next, the queen and king will concentrate on egg production. They’ll spend the rest of their lives populating their colony. They could be in for a long haul — queen termites may live 20 years or more.

Usually considered a primitive group of insects, termites have an incomplete metamorphosis: Eggs hatch directly into nymphs that look like adults. In the colony, the nymphs assist the non-reproductive adults (workers) in building and maintaining the nest, and in caring for the reproductive adults and eggs.

All species of termites are social, most creating colonies of three basic castes: reproductives, workers, and soldiers. The reproductives of established termite colonies add to the egg-laying of the founding queen and king. While worker ants and bees are non-reproducing females, individual worker and soldier termites are either males or females.

Some of the reproductives in a mature colony are born with wings (called “alates”) that allow them to leave the parent colony, mate, and establish a new colony. In our most notable species, the giant dampwood termite, the alates take to the air in fall. These are the large, chestnut-red termites we see flying at dusk on a placid autumn evening.

The giant dampwood termite is one of the largest of over 2,000 species of termites in the world, with queens nearly an inch long. Dampwood termites live in and on damp wood that’s on or in the ground and are found only in Pacific Northwest, California, and Nevada. Drywood and subterranean termites are found in other places in North America and around the world; mound-building termites, not found in North America, thrive in warmer regions.

All termites are wood eaters. However, termites cannot digest the tough cellulose in wood. Cellulose chewed up by the termites is broken down into more usable chemicals by the protozoa living in the termites' intestinal tracts. Though microscopic, these protozoa can make up to a third of the termite's overall body weight.

Termites also eat the cast skins and droppings of colony-mates, as well as dead or dying members. Such recycling conserves the edible wood particles, spores, and other materials on and in the termite bodies, in addition to passing intestinal protozoa on to the next generation.

Termites play a key role in breaking down large masses of tree wood to material that can be used by new plants -- breaking down building lumber as well as forest logs. Bored deep into wood, termite burrows introduce air, water, and plant roots that further break down and recycle the wood.

Termite borings also make it easier for larger animals to mine their own burrows and nesting holes. And, certainly, the termites themselves are prized food for many animals, from centipedes to birds to bears.

As autumn winds down into winter, these dispersed termites will settle down to decades of processing and recycling the stumps and downed logs awaiting them.

For information on how you can arrange an exploration of our fascinating natural history, contact Marty at 541-267-4027, mgiles@wavecrestdiscoveries.com, or www.facebook.com/wavecrestdiscoveries. Questions and comments about local natural history are welcome.