Efficacy of Entomopathogenic Nematodes Against Three Species of Stored Product Insects

Abstract

Two specis of entomopathogenic nematodes (EPNs), Steinernema riobravi, symbolized by Sr, and Heterorabditisbacterophora, symbolized by Hb,were tested by using five concentrations: 125, 250, 500, 1000, and 2000 an infectiousphase, ml of the type Sr and four concentrations of 500, 1000, 2000 and 3000infectious phase/mlof the type Hb against Cowpea weevil, Callosobruchus maculates,Khapra beetle, Trogoderma granarium, and Rust red flour beetle Triboliumcastaneum, using three exposure times of 24, 48, and 72 h. The mortalityrate increased withincreasing in concentrations and the exposure period. The results showed that the highest mortality rate was 16.67 whole insects recorded for the 2000 infectious phase/ml with Sr nematodes after 72 hours post- treatment ofC. maculatus. The results showed that the highest rate mortality,which is 20 larvae, was recorded for the infectious phase dose of the genus nematode (Hb), all of which are 500, 1000, 2000 and 3000 gastricphase/ml, and for all exposure periods used between 24 hours and up to 72 hours against the larvae of the T. granarium. The results showed that the highest rate of mortality 10.00 whole insects was recorded for the dose of 3000 Infectious stage/ml and at the exposure time 72 hours, while the lowest rate for this mortality of 1.33 adult insects for rusty flour beetle was recorded for the dose of 500 infectious stage/ml and for the exposure time only 24 hours. The resultsindicated that mortality rate was increasing against any increase in both the exposure time and the dose of nematodes of the genus Hb.