PATHOGENICITY OF ENTOMOPATHOGENIC FUNGI FROM LEBANESE SOILS AGAINST APHIDS, WHITEFLY AND NON-TARGET BENEFICIAL INSECTS

Three newly isolated and two existing isolates of M. anisopliae and B. bassiana were tested against aphids,whiteflies and beneficials, individually and with chitin synthesis inhibitor. Hundred percent of aphids have died of fungaltreatments 7 days post inoculation, but number of individuals that developed mycosis varied depending on the isolate used.Whiteflies, however, were slightly more resistant. All tested isolates appeared to be fast killing fungi requiring only one ortwo days for reducing aphid population by half and needing 4 to 6 days for 50% of whiteflies to succumb to the disease.Both, aphid and whitefly, mortalities increased with increasing dose. The estimated LC50 values against M. persicae were103.88 and 104.75 conidia ml-1, respectively. These results were comparable with values obtained for the same isolates testedagainst whitefly Bemisia tabaci. Hundred precent of parasitized aphids by whitefly parasitoid demonstrated the emergencehole in the controls and in the individuals treated with new M. anisopliae isolate and 87% of emergence holes in theindividuals treated with new B. bassiana. Exposure of mealybug predator to new isolates resulted in high mortalities. NativeB. bassiana isolate in combination with diflubenzuron significantly reduced population of 1st instar larvae of whiteflies undergreenhouse conditions 14 days post treatment.