Integration of entomopathogenic nematodes with Bacillus thuringiensis or pesticidal soap for control of insect pests

Abstract The integration of entomopathogenic nematodes and Bacillus thuringiensis subspecies kurstaki or a pesticidal soap controlled insect pests inhabiting the soil and foliage in the greenhouse. The nematode Heterorhabditis bacteriophora controlled larvae of the masked chafer Cyclocephala hirta or the black vine weevil Otiorhynchus sulcatus in the soil and a commercial formulation of B. thuringiensis (Javelin) controlled larvae of the cabbage looper Trichoplusia ni on foliage. The combination of H. bacteriophora or Steinernema carpocapsae with a pesticidal soap (M-Pede) was effective against larvae of the spotted cucumber beetle Diabrotica undecimpunctata undecimpunctata in soil and all feeding stages of the cabbage aphid Breuicoryne brassicae on foliage. After combining and immediately applying both the nematode and B. thuringiensis or pesticidal soap, positive results were obtained against insects in the soil and on foliage. The combinations of nematode and B. thuringiensis or pesticidal soap were held for 4 days with or without aeration, and the fate of the nematodes was observed daily. Both nematode species survived well in the B. thuringiensis formulations with aeration. Without aeration, S. carpocapsae was unaffected by the B. thuringiensis formulations, but H. bacteriophora showed poor survival in the two commercial formulations (Javelin after 1 day and Biobit after 3 days). With or without aeration, both nematode species were adversely affected in the pesticidal soap, but H. bacteriophora showed a higher mortality rate than S. carpocapsae .