Efficacy of entomopathogenic nematodes against Spodoptera littoralis (Boisd.) and Agrotis ipsilon (H.) (Lepidoptera: Noctuidae)

The study aimed to evaluate the efficacy of the EPNs against the larvae of Egyptian cotton leaf worm Spodoptera littoralis (Boisduval) and the black cutworm Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae) in vitro before in vivo study. The susceptibility of both larval species to the entomopathogenic nematode species, Steinernema monticolum and Heterorhabditis bacteriophora , was evaluated under laboratory conditions. The concentration of 400 IJs/dish for S . monticolum achieved up to 97.77 and 95.55% mortality rates of the 5 larval instars from 2nd to 6th instars of S . littoralis and A . ipsilon , respectively after 72 h. The concentration of 800 IJs/dish recorded larval mortality rates of 41.86 to 100% against 2nd to 6th instars of A . ipsilon larvae, after 72 h. At the lowest concentration (50 IJs/dish), the larvae of S . littoralis were more susceptible to H . bacteriophora than the larvae of A . ipsilon . The data indicated that 200 IJs/dish was the most effective concentration for all larval stages of both insect pests because the mortality percentage was 100%.