Termite Researchers Find a Source of Calm Before the Swarm

Most signs of spring, like budding trees, are worth celebrating. But for many in the South, the annual emergence of fertile, winged termites swarming furiously to scatter and search for mates isn't one of them.

In New Orleans, as the swirling, airborne masses of termites become more conspicuous, researchers with the Agricultural Research Service (ARS) are busy developing a biopesticide that could someday knock down large numbers of Formosan subterranean termites--before they ever take flight.

Maureen Wright, Ashok Raina and Alan Lax--researchers in the ARS Formosan Subterranean Termite Research Unit--have discovered a new strain of the fungus Metarhizium anisopliae that is highly effective against alates, the adult swarming form of the termite.

The invasive Formosan termite causes hundreds of millions of dollars in damage and control costs each year. Emerging in late April through June, the winged adults fly briefly before they drop to the ground, shed their wings and find a mate with which to start a new colony that may grow to hundreds of thousands of wood-destroying termites.

The researchers' find is significant, according to Raina, because many current control efforts focus on eliminating termite workers in colonies--not on destroying alates during the crucial period before they form new colonies.

Raina stumbled across the novel fungal strain after capturing dozens of swarming alates for other studies. To his surprise, all of the insects died within 24 hours. The culprit? A velvety, light-colored fungus overrunning the termites' bodies.

While a strain of Metarhizium has already been commercialized for termite control, this new isolate is especially lethal to alates--killing them in only three days. According to Wright, just as some people can run faster than others, some fungi are simply more potent than others of their closely-related cousins.

The researchers are currently seeking collaborators to further develop a formulation to deliver the fungal spores. They envision applying the fungus to buildings and trees already known to harbor termites before the swarms are in full swing.

ARS is the U.S. Department of Agriculture's chief scientific research agency.