Compatibility of insecticides with Metarhizium brunneum (Petch) and Beauveria bassiana (Bals.) for bio-intensive management of pink mealybug, Maconellicoccus hirsutus (Green) in grapes

Abstract

Grape (Vitis vinifera Linnaeus) is a high-value crop and important as a valuable export commodity for India. Pink mealybug, Maconellicoccus hirsutus (Green) is one of the most important pests infesting grapes. Two entomopathogenic fungi were isolated from the field infected insects and were identified as Metarhizium brunneum (Petch) and Beauveria bassiana (Bals.). The pathogenicity study showed that both the fungi were capable of infecting M. hirsutus. LC50 values 1.4 × 106 and 1.0 × 107 conidia per ml was recorded for M. brunneum and B. bassiana, respectively. Evaluation of compatibility of these fungi with insecticides is important to develop bio-intensive management strategy for mealybugs. The compatibility of seven insecticides (emamectin benzoate, tolfenpyrad, imidacloprid, clothianidin, buprofezin, fipronil, spirotetramat) with these entomopathogens was evaluated under laboratory conditions. Compatibility studies based on sporulation, germination and vegetative growth of fungi showed that imidacloprid and emamectin benzoate were most compatible and tolfenpyrad and spirotetramat were highly incompatible with both the entomopathogens.