Louisiana is home to a relatively high number of termite species that are known pests of woodwork. Multiple drywood and subterranean termite species inflict hundreds of millions of dollars in property damage each year in Louisiana alone, and much of this damage occurs in New Orleans where the highly destructive Formosan subterranean termite is most prevalent in the state. New Orleans is also home to an abundance of antiquated structures that are highly vulnerable to termite damage, especially subterranean termite damage. Four drywood and four subterranean termite species are common pests throughout Louisiana, and the nests constructed by each of these two termite groups differ greatly.

Subterranean termites account for around 80 percent of all termite-related property damage, and their colonies are located entirely underground within moist soil. Drywood termite colonies are contained entirely within individual pieces of damp and decayed wood, such as logs, fallen branches and dead parts of trees. Termites are highly dependent on moisture, and they will rapidly dessicate and die if exposed to the outside air. This is why termites prefer to infest wood that has become saturated with moisture. As their name suggests, drywood termites are able to infest relatively dry wood sources that subterranean termites could not tolerate, but drywood termites also require moisture in order to survive.

Drywood termites tunnel into the moistest areas within wood where they excavate a dwelling chamber for their nestmates. Drywood termites are physiologically equipped to extract significant amounts of water from the wood they eat, and consequently, their fecal pellets are noticeably hard and dry. When fecal pellets become too abundant within their nesting chamber, drywood nymphs excavate an “exit hole” on the surface of infested wood in order to discard their feces, or “frass.” In order to avoid the deadly effects of outside air, drywood nymphs quickly patch exit holes with a hardening mixture of saliva, wood and feces. The presence of frass piles within homes is often the first sign that a drywood termite infestation has become established.

Unlike drywood termites that dwell entirely within one structurally defined nest, subterranean termites do not dwell in single-structured nests; instead, their nests are diffuse, and their habitat in soil keeps workers moist while foraging long distances away from their nesting site. Because of these nesting differences, subterranean termite infestations are initiated by foraging workers, while drywood termite infestations are initiated only by seasonal swarming termites (alates).

Have you ever found frass in your home?