The goals of this project were to 1) identify toxins derived from Bacillus thuringiensis (Bt) with toxicity against Asian citrus psyllid (ACP), 2) isolate a peptide that binds to the gut of ACP, and 3) modify the selected Bt toxin with the gut binding peptide to provide an artificial anchor for the toxin resulting in enhanced toxicity. We screened toxin mixtures derived from 35 strains of Bt with diverse insect toxicities and toxin profiles for toxicity against ACP. The bioassay protocol was optimized to avoid toxin precipitation, but control mortality was high in some of the bioassays. Of the 35 strains screened, statistical analysis could only be conducted on data generated for 18 strains. Of these, toxin mixtures derived from a total of six Bt strains showed toxicity to adult ACP at 500 �g/mL of proteolytically activated toxin. Individual toxins from one of these strains were identified by LC-MS/MS, cloned, expressed, and tested against adult ACP. Of four individual toxins tested, one showed significant toxicity against adult ACP at 500 ug / ml. Given the smaller size of nymphs and large volumes of phloem ingested, it is expected that toxin efficacy will be greater against nymphs than against adult ACP. ACP mortality was associated with severe disruption of the midgut epithelium for the individual toxin and toxin mixture. The microvilli that line the gut epithelium were disorganized or lost, consistent with the mode of action of Bt-derived toxins. Toxicity also correlated with a drop in honeydew secretion indicative of reduced feeding which is also consistent with Bt toxin effects. We screened a phage display library to identify short amino acid peptide sequences that bind to the gut epithelium of ACP. This screen resulted in identification of four candidate peptides. Of these, two were shown to bind to the ACP gut when fused to the reporter enzyme, mCherry but only one, peptide 15, was found to bind specifically to the gut in competition assays. Peptide 15 was shown to bind to a 50 kDa gut protein. Having identified specific insertion sites in the ACP-active Bt toxin, we constructed a set of modified toxins by addition to- or replacement of- amino acid sequences at four different sites in the toxin, with peptide 15. Some of the modified toxins did not express well using standard expression in E. coli. Expression of these modified toxins using different expression strategies is now underway. Once the expression protocol has been optimized, modified toxins will be purified and tested against ACP. It is expected that peptide 15 will provide a peptide anchor for increased toxin binding to the ACP gut epithelium, resulting in enhanced toxicity against ACP.