Bug Blog

Why Is Termite Swarming Behavior Unique In Arizona, And At What Time Of Year Do Termite Species Swarm In The State?

Generally, termite swarms occur during the spring and early summer months. At least this is true when it comes to the most common and widely distributed termite species in the United States. For example, termite swarmers (alates) from the most destructive termite species in the US, the eastern subterranean termite, tend to take flight during the spring and early summer in both southern and northern regions of the US. Swarming alates from the highly destructive Formosan subterranean termite species also take flight during the spring and early summer, as do most other termite species in the US, such as the dark southern subterranean termite and the light southern subterranean termites species. However, these common termite pest species do not inhabit Arizona; instead, Arizona is home to several unique termite pest species that have adapted to the state’s varying elevations and exceptionally dry desert landscapes. This is why termites in the southwest demonstrate some behaviors that are markedly different from common termite behaviors. While termite swarms generally occur during the spring and early summer, most termite species in Arizona swarm during mid to late summer, and some species in the state swarm during the winter, depending on elevation and other environmental factors.

In lower elevation cities in Arizona, like Yuma, Tucson and Phoenix, winged alates from the arid land subterranean termite species take flight from January until March. In higher elevation cities, like Flagstaff, Show Low and Sedona, these termites swarm during June and July. The Most destructive termite species in Arizona, the desert subterranean termite, swarms from July until September following bouts of rain during the monsoon season. Alates from the dark western drywood termite species swarm from June until August on sunny days, and these swarms are not associated with rainfall. Foraging termites and alates from this species are active in urban areas located at elevations below 6,000 feet. Another drywood species, the light western drywood termite, is active at elevations below 4,000 feet where around 20 swarming events occur between June and September at dusk, and like the dark western drywood termite, these swarms are not associated with rainfall.

Have you ever witnessed a termite swarm during the winter?