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. A new logistic regression analysis indicated that 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 shown to have toxicity to ACP in bioassays were selected for modification with gut binding peptide 18. These modifications are now underway. Honeydew production data collected during the course of ACP bioassays both with toxin mixtures from Bt strains and with individual toxins, were analyzed to determine whether ACP died from starvation. Toxin-mediated damage to the gut epithelium can result in an anti-feedant effect. Honeydew excretion was monitored on the third, seventh and eleventh day of ACP feeding with the relative quantity of ACP excretions present in each feeding chamber recorded. Based on these data, toxin mixtures derived from four of the Bt strains had an anti-feedant effect on ACP, resulting in mortality from starvation.