Entomopathogenic nematodes for the biological control of insects.

Nematode parasites of insects have been known since the 17th century (33), but it was only in the 1930s, that serious consideration was given to using a nematode to Control an insect. In 1929, Glaser and Fox (19) found a nematode infecting grubs of the Japanese beetle, PopilIiajaponica, at the Tavistock Golf Course near Haddonfield, New Jersey. Steiner (44) described the nematode that same year as Neoaplectana (= Steinernema) glaseri. We now know that these nematodes carry a symbiotic bacterium which provides essential food for the nematodes whether they are infecting a host or in culture. Glaser was not aware of the symbiotic bacterium (5); nonetheless, the methods that he devised to culture the nematode in vitro were suitable for the bacterium to multiple (16,17). Glaser and colleagues produced sufficient numbers of the nematode for field trials and in the 1930s applied it to 73 different field plots in New Jersey to control the Japanese beetle (17,20). Parasitized grubs were recovered from 72 of the 73 plots two weeks after application. Parasitism of the grub population by the nema-