Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: January 10, 1996
Publication Date: N/A
Research on the use of Beauveria for control of Bemisia argentifolii was initiated by USDA-ARS-SARL in 1990. Initial laboratory and field tests indicated considerable biological control potential, and a collaborative agreement was established with Mycotech for mycoinsecticide research and development in 1993. In small-scale field trials in cantaloupe, cucumbers and tomatoes, approximately five applications of B. bassiana made at 4-5 d intervals at a rate of 1-2 x 10(13) conidia acre(1) using portable air- assist and hydraulic sprayers produced 80-95% control of larval whiteflies. Aqueous suspensions of the hydrophobic conidia were readily prepared using organosilicone surfactants at 0.03-0.04%. On the basis of these positive results, Mycotech submitted a wettable powder formulation of B. bassiana strain GHA (trade named Mycotrol WP) to the U.S. Environmental Protection Agency in 1995, and registration was granted in March 1996. Mycotech is now building a production facility in Butte, MT; current small-scale production is supporting field trials in the southern USA and Mexico. Tests employing conventional tractor driven spray equipment identified spray coverage as the most important predictor of efficacy. Weekly applications producing deposits of 1200 versus 200 spores per mm(2) on the lower surfaces of melon leaves resulted in 66 and 20% infection, respectively. Studies are in progress to maximize coverage through manipulation of various spray parameters.