Formosan subterranean termites are a particularly vigorous species of subterranean termite that has spread to this country. They have caused considerable damage in Hawaii and Guam and have been found in several locations on the United States main land.

It is anticipated that they could eventually become established along southern coasts, the lower East and West Coasts, in the lower Mississippi Valley, and in the Caribbean. The most obvious characteristics that distinguish Formosan subterranean termite swarmers from those of native species are their larger size (up to16 mm compared to 9 to 13 mm) and hairy wings (compared with smooth wings in other subterraneans).

Soldiers have oval shaped heads, as opposed to the oblong and rectangular heads of native soldiers. Formosan termites also produce a hard material called carton, which resembles a sponge. This is sometimes found in cavities under fixtures or in walls adjacent to attacked wood. Other characteristics - and control methods - are similar to those for native subterranean termites.

Formosan subterranean termites are more vigorous and can cause extensive damage more rapidly than do native species. For this reason Formosans should be controlled as soon as possible after discovery.