Submitted to: Society for Invertebrate Pathology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 9/30/1998
Publication Date: N/A
Technical Abstract: Field plots of irrigated spring-planted wheat in southeastern Idaho were infested with Russian wheat aphids and later treated with spores of either Beauveria bassiana or Paecilomyces fumosoroseus. Small plots (20 m2) were treated with a backpack sprayer in 1995-1997. Significant reductions in aphid populations were observed in all 3 years following 1 or 2 applications of B. bassiana as Mycotrol WP or Mycotrol ES. Fifty- two percent mycosis was observed among aphids on a subsample of field- treated wheat tillers. For P. fumosoroseus, significant reductions in aphid populations were observed in 1995 but not 1996 following 1 or 2 applications of conidia or blastospores formulated as suspensions with the surfactant Silwet. Eighty-three percent mycosis was observed among subsampled aphids maintained in the lab. Persistence of fungal inocula of either species, measured by estimating CFUs obtained from washed leaf samples, dropped to undetectable levels within 3 to 5 days. In 1997, Mycotrol ES (B. bassiana) was applied once to larger plots (0.4 ha) using a moveable pipe irrigation system. Aphid populations in treated plots dropped significantly within 2 weeks after treatment. These studies demonstrate the potential for control of Russian wheat aphid using fungi and illustrate a feasible large-scale application scheme.