Nematodes

Abstract

This chapter focuses on a group in the Family Rhabditidae that are called entomopathogenic nematodes (EPNs), which occupy the lethal extreme of this continuum. It includes short descriptions of nematodes in the families Mermithidae and Neotylenchidae. These three groups of nematodes have very different life-history characteristics, and stand to illustrate the diversity of parasitic relationships between nematodes and insects, although some characteristics are common to all species. The chapter also focuses on the Heterorhabditidae and Steinernematidae, because the other rhabditids that are considered EPNs are not as well characterized ecologically and are not used in biological control applications. Transmission of EPNs is horizontal. Horizontal transmission occurs primarily from soil to insect, although transfer may also occur via other substrates or from infected insect to live host. Selective breeding of EPNs or genetically engineered volatile emissions improves pest control efficacy, which can result in pest-control efficacy similar to that of chemical insecticides.