PHYSICAL DETERRENTS TO INFECTION BY ENTOMOPATHOGENIC NEMATODES IN WIREWORMS (COLEOPTERA, ELATERIDAE) AND OTHER SOIL INSECTS

Many soil-inhabiting insects are susceptible to entomopathogenic nematodes but the degree of susceptibility ranges widely. Much is understood about the habitat of insect pests in relation to their susceptibility but little attention has been paid to the influence of physical deterrents. ''Physical deterrents'' is used here to include morphological barriers (passive deterrents) and behavioural responses to attack (active deterrents). The roles of both are reviewed and discussed, in particular with reference to wireworms (Elateridae), a group of insects generally resistant to the nematodes. Knowledge of insect morphology and behaviour as well as habitat is important in predicting susceptibility to entomopathogenic nematodes.