evaluation of conidia-dust formulation of the entomopathogenic fungus, metarhizium anisopliae to biocontrol the brown-banded cockroach, supella longipalpa f.

background the brown-banded cockroach supella longipalpa (f.) as a mechanical vector of pathogens and source of allergens has recently become widespread in the city of ahvaz, southwestern iran. objectives this research was done to evaluate the efficacy of a dust-formulation of metarhizium anisopliae isolate iran 437c, as a common entomopathogenous fungus, against s. longipalpa. materials and methods conidia dust-formulations of m. anisopliae were prepared in proportions of 1%, 5%, 10%, 25%, 50% and 100% with bad wheat flour as the carrier. cockroaches were exposed to surfaces treated with 1.5 mg/cm2 of the formulations under laboratory and semi-field conditions. results cockroach mortality rates increased and survival times (st50) decreased with an increased proportion of conidia from 1% to 100% but records taken for mortality and survival time from proportions of 25%, 50% and 100% were not significantly different. the mortality rates reached 100% and 90-100% in adults and nymphs, respectively on the seventh day. the lowest st50 was related to the proportion of 100% (3 days). probit analysis indicated ld50 and ld90 values of 1.7 × 106 and 1.7 × 107 conidia/cm2 for adults and these values changed to 4.5 × 106 and 2.9 × 107 for third and fourth instar nymphs at three days post exposure. proportion of 25% caused mortality rates of 87%, 81% and 73% in adult, adult & nymph and nymph populations, respectively at four days after exposure under room conditions. conclusions conidia dust-formulation of m. anospliae isolate iran 437c could present a promising alternative to control the brown-banded cockroach.