Laboratory evaluation of the entomopathogenic fungi, Iranian isolates of Beauveria bassiana (Balsamo) Vuillemin and Metarhizium anisopliae (Metsch) Sorokin against the control of the cowpea weevil, Callosobruchus maculatus F. (Coleoptera: Bruchidae)

摘要

In this study, the pathogenicity of five Iranian isolates of?Beauveria bassiana?andMetarhizium?anisopliae?was?evaluated against adults of?Callosobruchus maculatus?adults by immersion bioassay method at 27 ± 1°C and 60 ± 5% R.H. under laboratory conditions.Cumulative mortality of the cowpea weevil at day 11 after treatment with?B. bassianaisolates IRAN 187C, IRAN 429C, IRAN 441C and?M. anisopliae?isolates IRAN 715C and DEM I001 by conidial suspensions at low and high concentration ranged between 29.4?to86.2, 9?to?88.3, 21.1?to?96.3, 24.8?to?84.4 and 20.9?to?80.9%, respectively.?The LC50?and LT50?values for IRAN 187C, IRAN 429C,?IRAN 441C,?DEMI001 and IRAN 715C?were 1.9×107, 9.8×106,?2.4×107,?2.6×108?and?1.2×108?conidia/ml and?7.8, 6.7,?7.2, 7.7 and 7.8 day, respectively.?IRAN 441C of?B. bassiana?had?the?highest virulence against adult cowpea weevil because it had lower?LC50?and?LT50?and caused?the?highest mortality (76%) in?treatment by suspensions containing?1×108?conidia/ml.?B. bassiana?had higher virulence than?M. anisopliae?against adult of cowpea weevil.?Key word:?Biological control, immersion bioassay,?virulence, cowpea weevil.