Monday, December 10, 2007 - 10:17 AM

Pathogenicity of Peruvian Paecilomyces fumosoroseus isolates against the silverleaf whitefly Bemisia tabaci biotype B (Hemiptera: Aleyrodidae)

Jorge Achata, jorgeachata@yahoo.com1, Marcel Gutiérrez-Correa,, Jürgen Kroschel, jkroschel@cgiar.org3, Norma Mujica, nmujica@cgiar.org3, and Octavio Zegarra, ozegarra@cgiar.org3. (1) New Mexico State University, Entomology, Plant Pathology and Weed Science, 2515 Cole Vlg, Las Cruces, NM, (2) Universidad Nacional Agraria La Molina, Laboratorio de Miocología y Biotecnología, Av. La Universidad s/n, Apartado 456, Lima 1, Lima, Lima, Peru, (3) International Potato Center (CIP), Entomology, Apartado 1558, Lima, Lima, Peru

The silverleaf whitefly is a world wide distributed pest that feeds on more than five hundred plant species and produces economically important yield losses on crops. The pathogenicity of twenty Peruvian isolates of the entomopathogenic fungus Paecilomyces fumosoroseus was screened on second stadium nymphs. Excised sweetpotato leaves with second instars attached to them were dipped in conidia suspensions and incubated for twenty days. All the tested isolates were infective and from them CIPWF24 was selected as the most pathogenic in the group. Five concentrations of CIPWF24 conidia were used to assess the Medium Lethal Concentration (LC50) which was estimated on 2.24 x 107 conidia/ml for the second stadium. Results indicate that the isolate CIPWF24 produced significant infection on whitefly nymphs and that this may vary according to the age of the insect.

Species 1: Hemiptera Aleyrodidae Bemisia tabaci (silverleaf whitefly)