Bacterial entomopathogens have not been adequately investigated as potential microbial agents for control of the citrus root weevil, Diaprepes abbreviatus. The bacterium, Bacillus thuringiensis is known to be pathogenic to many insect pests but relatively few strains are active against coleoptera. Endotoxins produced by the bacterium are activated in the gut of susceptible hosts upon ingestion, and can cause feeding inhibition, infection of host tissues, and eventual death. Researchers at the U.S. Horticultural Research Laboratory have assembled two collections of B. thuringiensis isolates that are plausibly active against D. abbreviatus. One collection contains patented isolates that demonstrate activity against coleoptera. The other collection is comprised of isolates obtained from diseased larvae of D. abbreviatus collected in Florida citrus groves. Isolates from both collections are being screened for activity against neonatal and 3-4 week old larvae of D. abbreviatus. Effective rates are determined for isolates that demonstrate activity in initial screening experiments. Application strategies developed for particularly promising isolates may include transgenic approaches as deemed appropriate.