Entomogenous Nematodes as Biological Control Organisms for Ligyrus subtropicus (Coleoptera: Scarabaeidae) in Sugarcane

Five entomogenous nematodes, Steinernema feltia Filipjev (= Neoaplectana carpocapsae Weiser) (All, Mexican, and Breton strains), S. glaseri (Steiner), and Heterorhabditis heliothidis (Khan, Brooks, and Hirschmann) were evaluated in the laboratory against the white grub Ligyrus subtropicus (Blatchley), a serious pest of sugarcane in Florida. When applied in lots of 5,000 nematodes per larva, S. glaseri caused significantly higher mortality to third-instar white grub larvae than the other nematode species tested. Mortality of white grub larvae exposed to 250 S. glaseri nematodes per larva was not significantly different from mortality of larvae with 4,000 nematodes per larva. L. subtropicus appears to be an excellent host for S. glaseri , yielding a mean of 139,576 nematodes per larva when inoculated with 1,000 nematodes per larva. S. glaseri might be used for biological control of L. subtropicus in Florida sugarcane.