Evaluation of entomopathogenic fungi against Raoiella indica Hirst (Acari: Prostigmata: Tenuipalpidae)

Abstract

Entomopathogenic fungi Metarrhizium anisopliae, Beauveria bassiana and Lecanicillium lecanii tested against immature and adults of Raoiella indica under laboratory condition with five different concentrations of each sprayed on leaf discs containing larvae, nymphs, and adults, indicated that all life stages were susceptible. Larval and nymphal stages were generally less susceptible than adults. Based on probit analysis, L. lecanii was the most virulent with LC50 of 8.15 × 105 conidia ml-1 and 1.30 × 105 conidia ml-1 followed by M. anisopliae 18.05 x 105 conidia ml-1 and 2.70 × 105 conidia/ml and B. bassiana (27.13 × 105 conidia ml-1 and 4.80 × 105 conidia ml-1) for immature and adults, respectively. However the efficacy of the fungal pathogens evaluated clearly differs from that of the controls. These entomopathogenic fungi could be considered as an environmentally friendly alternative for biocontrol of R. indica.