Date of this Version
In laboratory studies, infective juveniles of Steinernema feltiae Filipjev (=Neoaplectana carpocapsae Weiser) (All strain) and Heterorhabditis heliothidis (Khan, Brooks & Hirschmann) were tested for their ability to control third-instar European chafer (EC), Rhizotrogus majalis (Razoumowsky), in soil at rates from 19.4-310.0 nematodes per cm2 of soil surface. H. heliothidis provided better control of EC larvae than S. feltiae over the range of rates tested. After 25 d, treatment with H. heliothidis provided 94% control of larvae at the lowest rate tested (19.4 per cm2). In a field test in turf against a mixed population of Japanese beetle, Popillia japonica Newman, and EC larvae, H. heliothidis (310 per cm2) provided >60% control (47 d after treatment), which was equivalent to the control achieved with the labeled rates of chlorpyrifos, trichlorfon, and isofenphos against this combination of white grubs.