Colonies of subterranean and drywood termites contain numerous individuals that are divided into different groups, or “castes.” The worker caste accounts for the vast majority of individuals within a subterranean termite colony, and they are responsible for foraging, nest construction, and feeding and grooming nestmates. Drywood termite colonies are contained entirely within single wood items, making their habitat and food source one and the same. This makes foraging unnecessary and impossible, as drywood termites never leave the wood items that they colonize. However, nest expansion, nestmate feeding and other laborious tasks are carried out by nymphs, which are similar to workers in subterranean termite colonies.
Both subterranean and drywood termite colonies contain a soldier caste responsible for defending the colony, and of course, all termite colonies contain a queen and king. After a few years of colony maturation, queens produce alates, which are winged reproductives that take flight for a few months each year in order to establish new colonies as queen and king. Homeowners often become alarmed upon witnessing termites swarming within and near their home, especially when swarms are witnessed near homes that have recently undergone a perimeter barrier treatment for the purpose of preventing subterranean termite infestations.
In Arizona, both subterranean termites and drywood termites frequently infest homes, but subterranean termites inflict the greatest amount of damage to homes annually. When it comes to drywood termites, only alates leave the colony, and therefore, only alates initiate infestations in structural wood. Subterranean termite alates, establish new colonies in soil, and almost never in wood; instead, workers infest wood after encountering homes while foraging. The application of termiticide liquid beneath the ground around the perimeter of homes prevents workers from tunneling onto properties.
Oddly enough, it is not uncommon for homeowners to witness termite swarms occur near their home shortly after having a perimeter treatment applied to their property. This can lead homeowners to believe that their home remains vulnerable to termites, and this natural response is referred to as a “panic swarm” in the pest control industry. However, it should be known that the application of termiticide below the ground can put stress on nearby subterranean termite colonies that become exposed to the toxins. In order to ensure survival in these circumstances, swarming rates may increase as a biological response to environmental stress. Swarms should only be of concern when they occur indoors.