Simultaneous Use of Entomopathogenic Fungus <i>Beauveria bassiana</i> and Diatomaceous Earth against the Larvae of Indian Meal Moth, <i>Plodia interpunctella</i>

Abstract

The suppressive ability of entomopathogenic fungus Beauveria bassiana alone and in combination with diatomaceous earth (DE) was studied against the larvae of Indian meal moth, Plodia interpunctella ( Hübner ) (Lep., Pyralidae). This study clearly showed that simultaneous use of B. bassiana and DE against larvae of P. interpunctella , not only could reduce the required concentration of fungal conidia or DE, but also could shorten the time need for showing insecticidal effects. The LC 50 value of fungus at 7 d after treatment was 9.8 × 10 5 conidia mg -1 diet. Larvae showed a dose response to B. bassiana , and the addition of diatomaceous earth at 500 and 2000 ppm resulted in a significant increase in mortality. Larval mortality reached to the maximum of 28.3% and 71.7% after 7 d exposure to 500 and 2000 ppm DE concentrations, respectively. The LC 50 value for B. bassiana in the presence of DE 500 ppm was 4.6 × 10 4 con. mg -1 diet and of DE 2000 ppm was 1.65 × 10 3 con. mg -1 diet. According to our results, B. bassiana and DE can be considered as two suitable candidates for integration into IPM strategy.