Production technology for entomopathogenic nematodes and their bacterial symbionts.

Entomopathogenic nematodes (genera Steinernema and Heterorhabditis) kill insects with the aid of mutualistic bacteria. The nematode-bacteria complex is mass produced for use as biopesticides using in vivo or in vitro methods, i.e., solid or liquid fermentation. In vivo production (culture in live insect hosts) is low technology, has low startup costs, and resulting nematode quality is high, yet cost efficiency is low. In vitro solid culture, i.e., growing the nematodes and bacteria on crumbled polyurethane foam, offers an intermediate level of technology and costs. In vivo production and solid culture may be improved through innovations in mechanization and streamlining. In vitro liquid culture is the most cost-efficient production method but requires the largest startup capital and nematode quality may be reduced. Liquid culture may be improved through progress in media development, nematode recovery, and bioreactor design. A variety of formulations is available to facilitate nematode storage and application.