title: A strain of the fungus Metarhizium anisopliae for controlling subterranean termites.
abstract: Alates of the Formosan subterranean termite, Coptotermes formosanus Shiraki, collected after swarming in 2002 died within 48 h, and the cadavers were visibly infected with a fungus. Fungi were picked from the cadavers, transferred to media, and ultimately isolated to purity. The individual fungal cultures were then used to infect Formosan subterranean termite workers. A single fungal isolate, C4-B, taxonomically identified as Metarhizium anisopliae (Metschnikoff), was found to cause rapid mortality of Formosan subterranean termite alates. This is the first report of a biological control agent for termite alates. In initial experiments, C4-B was more lethal to both alates and workers compared with M. anisopliae strain ESC 1, previously marketed as the termite biocontrol agent BioBlast. Dose-response assays in which Formosan subterranean termite alates were exposed to a known concentration of C4-B spores revealed that 10(6) spores/microl killed 100% of the alates in 3 d, both 10(5) and 10(4) spores/microl in 6 d, 10(3) spores/microl in 9 d, and 10(0) spores/microl in 12 d. Assays with workers demonstrated that 10(6) and 10(5) spores/microl killed 100% of the workers in 6 d. In an experiment to test the transfer of inoculum from infected workers to uninfected nestmates, 62.8% of the workers died in 21 d when only 20% of the workers had been inoculated. Mortality of alates caused by C4-B was tested at two field sites by dispersing fungal spores on grassy lawns and collecting alates from the treated areas. Alates thus infected showed 100% mortality by day 5, whereas only 64.8% of untreated control alates from the same collection area were dead on that day.
authors.affiliation: Formosan Subterranean Termite Research Unit, USDA-ARS-SRRC, New Orleans, LA 70124, USA.
authors.forename: Maureen S
authors.initials: MS
authors.lastname: Wright
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Raina
authors.forename: Alan R
authors.initials: AR
authors.lastname: Lax
mesh_terms: D000818:Animals; D006999:Hypocreales / Q000502:physiology*; D007300:Insect Control / Q000379:methods*; D020049:Isoptera / Q000382:microbiology; D010572:Pest Control, Biological; D013172:Spores, Fungal