Aug. 17, 2009 03:20 PM
Swarming is a spring activity for most - but not all - species of subterranean termites. Flight times for species vary based on favorable weather conditions, which means that not all termite reproductives swarm at the same time.
In the eastern United States, the major species typically swarm about a month apart, with Eastern subterranean termites (Reticulitermes falvipes) going first in April, followed by dark Southern subterranean termites (R. virginicus) in May.
There is one termite species, light Southern subterranean termites (R. hageni), which prefers quite different weather conditions, opting to swarm in the fall. Swarms of this species may extend from August (cities along the eastern seaboard) to November (in the Deep South). The winged adults in this species are slightly smaller and pale brown, and often swarm during the same time of day as the spring swarmers (late morning). This species' size and color often gets it confused with ants that swarm at the same time of year.

William H. Robinson, Ph.D., TermiteTalk blogger