DESARROLLO in vitro DE CUATRO CEPAS NATIVAS DE Paecilomyces fumosoroseus Y SU PATOGENICIDAD EN ESTADOS INMADUROS DE MOSQUITA BLANCA In vitro DEVELOPMENT OF FOUR Paecilomyces fumosoroseus ISOLATES AND THEIR PATHOGENICITY ON IMMATURE WHITEFLY

The use of chemical insecticides in the management of whitefly ( Bemisia tabaci) (Gennadius) causes serious damage to the environment and has generated populations resistant to conventional products. A promising alternative is biological control by using entomopathogenic fungi. In the present study the in vitro development and pathogenicity of four native strains (Pf-Tim-Tiz Pf, Pf-Hal, Pf-Rg), as well as a commercial (Pae-sin) of Paecilomyces fumosoroseus (Wize) Brown & Smith were evaluated in eggs and first instar nymphs of Bemisia tabaci (Gennadius). The variables to assess the in vitro development were: daily growth rate of the colony (TCD), sporulation and spore germination rate (TGE). The pathogenicity of the strains was determined by dipping the leaves of Capsicum chinense, which contained the immature stages of B. tabaci in a conidial suspension 1×10 7