Production of two entomopathogenic Aspergillus species and insecticidal activity against the mosquito Culex quinquefasciatus compared to Metarhizium anisopliae.

The spore productivity and insecticidal activity of two opportunistic insect pathogenicAspergillusspecies (namely:Aspergillus clavatusDesmazieres andAspergillus flavusLink (Ascomycota: Eurotiales, Trichocomaceae)) were compared toMetarhizium anisopliaesensu lato (Metchnikoff) Sorokin (Ascomycota: Hypocreales, Clavicipitaceae) for mosquito (Diptera: Culicidae) control. The production of aerial spores on wheat bran and white rice was investigated in solid-, semi-solid-, and liquid-state media supplemented with a nutritive solution. Wheat bran-based media increased the spore yield in solid-state from three to sevenfold:A. clavatusproduced 48.4 ± 5.2 and 15.7 ± 1.6 × 108spores/g,A. flavusproduced 22.3 ± 4.1 and 3.1 ± 2.5 × 108spores/g, andM. anisopliaeproduced 39.6 ± 6.5 and 13.1 ± 2.6 × 108spores/g of wheat bran or white rice, respectively.A. clavatus,A. flavusandM. anisopliaespores harvested from wheat bran-based solid-state media showed lethal concentrations (LC50) of 1.1, 1.8, and 1.3 × 108spores/ml againstCulex quinquefasciatusSay larvae in 72 h. BecauseA. clavatusandM. anisopliaedisplayed similar features when cultured under these conditions, our results suggest that insect pathogenicAspergillusspecies may be as productive and virulent against mosquito larvae as a well-recognised entomopathogenic fungus. [ABSTRACT FROM PUBLISHER]