Studies on the virulence of different isolates of Beauveria bassiana (Balsamo) Vuillemin and Metarhizium anisopliae (Metcsn.) Sorokin against Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

摘要

Virulence of ten fungal isolates of entomopathogenic fungi,?Beauveria bassiana?(Balsamo) Vuillemin andMetarhizium anisopliae?(Metcsn.) Sorokin against third instar larvae of Mediterranean flour moth,?Ephestia kuehniella?Zeller, was tested under laboratory conditions. These isolates were originated from soil by usingGalleria mellonella?(L.) (Lepidoptera: Pyralidae) as a live insect bait. All isolates were inoculated by immersing the insects in 10 ml of a fungal suspension for 5 s. The experiments carried out with 3 replications and 10 larvae were used for each replication.Cumulative mortality after treatment varied from 11 to 92% in?M. anisopliae?and in?B. bassiana?from 17 to 88%. The increase of dose and exposure interval increased mortality. LC50?values ranged from 8.3 × 105?to 6.5 × 106?for?B. bassiana?and from 5.4×107?to 3.4×108?for?M. anisopliae. Among the isolates evaluated in the study, C-IIA7 isolate of?B. bassiana?had the lowest LC50.The LT50?values for these isolates varied from 107 to 154 h for?B. bassiana?and from 93 to 162 h for?M. anisopliae, whereas, B-VM1 isolate of?M. anisopliae, recorded the least LT50?of 93 h. Our results demonstrated that the entomopathogenic fungi could be used as an alternative for the control of stored products pests in IPM programs.