Entomopathogenic Nematodes as Biopesticides

Abstract

Entomopathogenic nematodes (EPNs) are microbial control agents which have become important in biological control or integrated pest management of insect pests as biopesticides. EPNs are widespread all over the world and are found in almost all places where there is agricultural land and forests, and in the desert where there are desert plants. Where insects are present in the environment, they may help the spread of EPNs of a number of species of the genera Steinernema (more than 61 species) and Heterorhabditis (more than 14 species). The factors responsible for aggregated distribution of EPNs may include behavior and the spatial and temporal variability of the nematodes’ natural enemies, such as nematode trapping fungus. Nematodes also have limited dispersal ability. Many infective juveniles are produced from a single host, which can also produce aggregates. Patchy EPN distributions may also reflect the uneven distribution of the host and nutrients in the soil. The metapopulation as a whole can persist as long as the rate of colonization is greater than or equal to the rate of population extinction.