A biological control is disclosed for termites, including subterranean termites such as C. formosanus, comprising a mixture of a chitin synthesis inhibitor such as lufenuron with a pathogen or opportunistic pathogen. The combination greatly enhances the effectiveness above that of the individual components. For example, P. aeruginosa is commonly found in association with termites, but it is not normally harmful to termites. However, in the presence of lufenuron, P. aeruginosa becomes an opportunistic pathogen that kills termites. As another example, B. thuringiensis, which otherwise has shown only limited effectiveness against termites, has greatly enhanced lethality in combination with lufenuron. In another aspect a termite toxicant is administered to termites in a clay-based bait. Clay acts as an attractant for subterranean termites such as C. formosanus, and a clay bait can increase a colonys consumption of a toxicant.
