Potential use of pathogenic fungi in baits to control the Formosan subterranean termite (Isopt., Rhinotermitidae)

A laboratory choice test was developed to assess the efficacy and acceptability of sporulating strains of Beauveria bassiana (Balsamo) Vuillemin and Metarhizium anisopliae (Metsch.) Sorokin to foraging Formosan subterranean termites, Coptotermes formosanus Shiraki. Filter paper disks were saturated with agar media and inoculated with either B. bassiana strain 787 or 3041, or M. anisopliae strain 346, 472 or 2162. Filter papers containing eight‐day‐old cultures were rolled into cylinders with the sporulating culture on the inside of the cylinder, and placed in one of two plastic jars, connected by a glass tube. Termites were placed in the other jar (refugia), and allowed to forage throughout both jars. This apparatus simulates the use of a fungal bait for subterranean termite control in the field. Termites did not avoid contact with the fungal baits, and fed upon the agar‐treated filter papers. Exposure to M. anisopliae strains 346 and 2162 resulted in rapid termite mortality while exposure to the B. bassiana strains caused slower, but escalating, mortality. Efficacy of the fungi was not affected by the degree of sterility of the termite tunnelling medium. Living cultures of entomopathogenic fungi hold promise for further development as baits for subterranean termite control.