Effects of some insecticides on the neutral lipid percentage, survival and infectivity of Steinernema carpocapsae ALL and Heterorhabditis amazonensis JPM 4

Abstract

Lipids are an important energy source for entomopathogenic nematodes (EPNs) and directly influence their infectivity in the host. Some insecticides reduce the infectivity of infective juveniles (IJs) while keeping them viable after exposure. Thus, the objective of this study was to correlate the amounts of lipid reserves in the EPN Heterorhabditis amazonensis JPM 4 and Steinernema carpocapsae ALL with their survival and infectivity when exposed to insecticides that keep the nematodes viable but reduced their infective capacity against Galleria mellonella . Among the tested insecticides, Vertimec(R) and Klorpan(R) were incompatible (class 2) with the two EPN species because they reduced infectivity. The insecticides Vertimec(R) and Klorpan(R) maintained the viability of the IJs but reduced their infectivity and their lipid amounts after insecticide exposure.