Due to environmental and regulatory concerns, research and development of nonchemical alternatives for pest suppression is necessary. Entomopathogenic nematodes are environmentally friendly biocontrol agents that can suppress a wide variety of economically important insect pests including the black vine weevil, the Japanese beetle, Diaprepes root weevil, and fungus gnats. Commercialization of these nematodes, however, has not reached its potential. Two critical hindrances to wider usage of entomopathogenic nematodes are inconsistent efficacy in field applications, and cost. Our challenge is to overcome these barriers. Prior research indicates nematodes applied in their infected-hosts may be more efficacious than nematodes applied through conventional means (i.e., aqueous suspension). Additionally, application of nematodes in infected-hosts is likely to reduce production costs. Our objective is to determine the feasibility of applying entomopathogenic nematodes in infected hosts. We will develop a novel in vivo system to produce nematode-infected-hosts, compare the efficacy of nematodes applied in infected-hosts with those applied in a conventional manner, and test various methods of formulation and storage for nematode-infected-hosts. Research will focus on Heterorhabditis bacteriophora. Once the technology is developed with this nematode, it will be easily transferable to other species. ANTICIPATED RESULTS & POTENTIAL COMMERCIAL APPLICATIONS OF RESEARCH This research will lead to development of a powerful biocontrol technology for suppression of arthropod pests. The cost of entomopathogenic nematode production will decrease and field efficacy will increase. The resulting biocontrol product will be initially targeted for control of major pests of ornamental and nursery plants (e.g., the black vine weevil, and white grubs). Once proven successful, markets can be expanded to various other commodities such as orchards, field, and even urban systems; the potential is vast. Substantial previous research, and