Just as their name suggests, subterranean termites live in below-ground colonies composed of anywhere between a few hundred to more than one million individuals, depending on species and colony age. Most of these individuals are workers that carry out a number of duties, such as foraging, nest construction, caring for offspring and the queen, feeding their nestmates, establishing secondary nests, and more. Large subterranean termite colonies that are more than 10 years old are composed of numerous secondary nests that surround the original primary nest. These networks of interconnected nests can span areas exceeding 100 square meters. The eastern subterranean termite (Reticulitermes flavipes) is the most widespread, destructive, commonly controlled and economically costly subterranean termite pest species in the US.

This termite pest is abundant in Massachusetts, particularly in residential areas located near wooded landscapes. Like all subterranean termite species, the EST is heavily dependent on soil moisture in order to survive, and exposure to the outside air will cause the insects to dry up and die. Because of this, subterranean termite colonies remain underground at all times, while numerous workers leave the colony to infest wood. Workers can only tolerate wood that is moist, but they must return to the moist soil to hydrate as needed. It is often said that native subterranean termites are unable to establish above ground infestations that are not connected to the ground soil, but the recent discovery of an EST infestation on a houseboat sheds doubt on this claim.

Several years ago, a team of pest control professionals arrived at a property in order to locate and treat an EST infestation. The 3,000 square foot house was unique for being located in the middle of a lake where termites could not possibly maintain contact with moist soil. Surprisingly, the house was found to be infested by a colony of EST. A few years later, the same team of pest control professionals found “mud tubes” protruding from a wooden wall in the cabin of a houseboat that had been located in open water. Mud tubes provide workers with an airtight bridge between two pieces of above ground wood. As they continued to inspect the houseboat, they heard distinct chewing sounds echoing throughout the cargo hold where moisture level readings were high. Upon closer examination, an extensive EST infestation was found in wood near the hull where unusually thick mud tubes were prevalent. It was later learned that workers had constructed these mud tubes from rust that had formed on the metal hull. An entire EST colony was found in the boat’s wood, indicating that the infestation must have been initiated by swarming ESTs (alates) in exceptionally moist wood near the boat’s hull. The two infestations described in this article prove that EST infestations can be initiated by swarmers within above ground wood as long as the wood is damp enough to meet an EST colony’s needs.

Have you ever heard of a docked boat that became infested with termites?