Living and Working Together: Termite Colonies
Termites like bees and ants are nest or colony dwelling insects and are closely related in taxonomic terms to cockroaches. Like bees and ants they live in a rigid hierarchical social organization that goes by the scientific term “eusocial” which is generally characterized by:
• Reproductive division of labor (with or without sterile castes)
• Overlapping generations
• Cooperative care of young
The Colony Structure of Termites
The termite colony structure is controlled by one reproductive pair, a queen and king. This mated pair can live as long as 70 years and is the foundation of the termite nest. The king and queen are supported by two other sterile or non-reproducing forms, the soldier and the worker termites.
Reproductives may, as a colony grows ever larger produce additional reproductives. These are usually lone queens who are controlled by the pheromones of the founding queen. Unlike other hive insects such as ants, the male reproductive king lives beyond the first mating, needing to periodically couple with the queen so that she can continue to produce fertile eggs. It may be periodically necessary for the termite colony to produce additional king reproductives as well, should something happen to the founding king.
Soldier termites are few in number in the colony and as their name suggests they function primarily as the defenders of the termite nest from predation by ants. Soldiers also build shelter and defensive fortifications for the burgeoning colony population. Soldier forms are characterized by pinchers or jaws that are so massive that the soldier termite is unable to feed itself, relying on the worker caste for sustenance.
The worker caste is by far the most populous; in any one termite nest the workers can number in the hundreds of thousands to millions. Worker termites feed and care for not only themselves but the king and queen, the soldier form, the egg brood and the juvenile or nymph workers. It is the worker caste which accounts for the destruction of homes. Only the termite workers carry the bacteria in their digestive systems that allows wood and other cellulose based matter to be digested and transformed into a food source to support the massive colony population.
The Life Cycle of a Termite Colony
Termite settlements are established primarily by a newly mated reproductive pair arriving at a likely nest site during a “swarm”. There is also a secondary and less well understood method of colony founding called “budding”.
Reproductives are also called “alates” and are the only winged form of the termite. They leave an established colony under favorable conditions in the early spring (but sometimes depending on species, in the late spring or summer) in a phenomenon known as “swarming”. Depending on the termite species, this is the release of between a few dozen to hundreds of the winged alates, who pair off, mate and fly off to find the proper environment in which to establish new nests.
Termite swarms generally take place during daylight hours (although the Formosan subterranean termite species is known to swarm primarily at night), may occur in one massive wave, or a series of repeated swarms during the warm months of the year.
As noted above, a large colony will often produce additional queens, which serve not only as additional breeding stock, but also are a form of insurance against something happening to the colony queen, a phenomenon known as “budding”. If a queen dies, one of these supplementary reproductives can take over her function as primary breeder. Sometimes natural disasters and other disruptions in colony integrity occur which result in part of a colony becoming isolated from the main population. Again, supplementary queens are produced to take over and head the “new” colony. Some of the more massive termite colonies will also routinely produce so called “satellite” colonies”.
Swarming is the primary method of termite colony creation and has been more thoroughly studied and documented than has budding. It is not known with any certainty how often budding occurs as a means of colony formation but it appears to be a much more rare occurrence—something of a failsafe against natural disasters, environmental disruptions or other events that can threaten an established colony.
Founding the Colony
Once a pair of alates finds a likely nesting site, the king and queen shed their wings and burrow into the food source. The species of termite determines the choice of nesting sites—some termite species prefer decaying logs and forest settings, but subterranean, drywood and dampwood termites prefer to invade manmade structures, there to feast on the rich sources of wood and cellulose based building materials such as sheetrock, drywall, plasters, even some kinds of insulation and roofing.
Subterranean species present the largest swarms and the biggest colonies, compared to the much smaller but no less destructive drywood and dampwood species. These colonies nest first below ground level in termite mounds, then travel via mud tubes across open spaces to infiltrate cracks or gaps in foundations, siding and roofing. Invading termites have also been known to chew through metal siding and other seemingly termite proof building features to reach the wood in the substructures. Dry and dampwood termites might launch more direct assaults, swarming directly into structures via gaps and cracks in structures, through light fixtures, window sills, roof eaves and door jambs.
The Colony Flourishes
Once a breeding pair has successfully mated and founded a new termite settlement, the population may take several years to mature and grow. If not detected in the swarming stage of an infestation, this is the “calm before the storm” of the destructive potential of a termite colony. The population steadily builds –and may reach after a period of on average five years millions of organisms. By the time a colony has reached the level of maturity where it begins to produce alates in significant swarms, it is likely well established and inflicting extensive damage on the structure in which it has settled. It is still possible to eradicate a mature colony, although the affected dwelling will require extensive repair and restoration.
Termite Colony Images
A useful tool for the homeowner is a library of images of termite colonies at various stages of formation and development. The images below may be useful for identifying a potential colony in and around a dwelling which is suspected to be under assault by a termite infestation.