Biological control of greenhouse whitefly, Trialeurodes vaporariorum byentomopathogenic fungus Lecanicillium muscarium hybrid strain 2aF43in greenhouse

Abstract: The Lecanicillium muscarium hybrid strain 2aF43-formulation (average of conidialconcentration 1.7×104spore ml-1), which was obtained by protoplast fusion and shown to have ahigh control potential in vitro, and the Mycotal®-formulation (3.0×106spore ml-1), which is acommercial biological agent with a high virulence against greenhouse whiteflies on tomato plantsin greenhouses, was investigated. On untreated tomato plants, the number of adult whitefliessignificantly increased to 354 adults per leaf during 8 weeks. In 2aF43-formulation andMycotal®-formulation plots, adult density remained at low levels (0.6 to 15.9 adults per leaf and0.5 to 11.3 adults per leaf, respectively) for 7 weeks. Evidence suggests that the hybrid strain2aF43-formulation, which has a substantially lower conidial concentration than the Mycotal®-formulation, has the potential for controlling early emergence of greenhouse whiteflies and thepossibility for long term effects in greenhouse use.