The objective of this project is first to identify a Bacillus thuringiensis (Bt) crystal toxin with basal toxicity against Asian citrus psyllid (ACP). The toxicity of the selected toxin will then be enhanced by addition of a peptide that binds to the gut of ACP. This peptide addition to the toxin is expected to enhance both binding and toxicity against ACP. The identification of Bacillus thuringiensis strains with basal toxicity against ACP was conducted by means of a series of bioassays using trypsin-activated toxin as described in previous reports. Seven isolates showed promise with ACP mortality at 500ug/ml relative to control treatments. A single strain was selected for further analysis and individual toxins expressed by this strain were identified by LC-MS/MS analysis. Two individual toxins were shown to have toxicity to ACP in bioassays. Electron micrographs of ACP fed on the wild type ACP-active toxins confirmed damage to the midgut epithelium associated with ACP mortality. Modification of one of the selected ACP-active toxins with gut binding peptide 18 has been completed. Work is now underway to identify the optimal expression strategy for the modified toxin constructs.