The Formosan subterranean termite (Coptotermes formanosus) is native to southeastern Asia, but they have established an invasive population in a majority of the southernmost US states. Since the first Formosan subterranean termite (FST) colonies were discovered in the US near the port of Houston back in the 1960s, this species has made a name for itself as an unusually destructive and economically costly pest of homes, buildings, and even living trees.

The FST spread rapidly across much of the Gulf Coast where it inflicted a seemingly impossible degree of damage to structures in New Orleans’ French Quarter, and to a lesser extent, structures in other major cities such as Houston and Mobile. In response to the unprecedented devastation FSTs caused in the French Quarter, federal and state authorities started working together to facilitate area-wide control programs to prevent the continued spread of the invasive pest.

While the native eastern subterranean termite (Reticulitermes flavipes) inflicts the greatest amount of property destruction annually in the US by virtue of its tremendously broad habitat range, FST infestations are more frequent and far more damaging. Because the FST is a tropical to subtropical termite species, their invasive habitat in the US is limited almost entirely to the southernmost states where they are most prevalent along the coast. However, a small number of FST colonies have been recovered as far north as southern Tennessee and North Carolina, and many academic researchers believe that global warming may allow FSTs to migrate farther north in the country where conditions could become hospitable to the pests.

Despite the FST’s restricted habitat range in the US, a recent nationwide survey of pest control firms found that FSTs were the eighth most commonly controlled wood-destroying insect pests on residential and commercial properties in the US during 2016. This makes the eastern subterranean termite and the western subterranean termite the only subterranean termite pests in the US that infest structures more frequently than the FST. This survey result was surprising to the lead researchers, as the shared habitat of the two above-mentioned native subterranean termite species completely cover each state within the contiguous US.

Temperature and relative humidity are the two most important factors affecting the survivability of FSTs, and research has conclusively demonstrated that FST specimens prefer conditions where temperatures range from 70 to 83 degrees fahrenheit and the relative humidity remains between 94% and 98%. When kept in conditions where the relative humidity drops below 75%, or the temperature falls below or exceeds the above mentioned temperature range, FST colonies will not survive.

Have you ever known someone who fell victim to a FST infestation?