Abstract: The present invention relates generally to modified Bacillus thuringiensis (Bt) insecticidal crystal proteins, also referred to as mutant toxins, with enhanced toxicity against a variety of insect genera, particularly mosquitos. The invention provides modified Bt Cry4Ba proteins, or mutant toxins, which have toxicity-enhancing sequence modifications at one or more positions within the amino acid sequence of the protein. The invention also provides polynucleotides encoding modified Cry4Ba proteins. The invention also provides insecticidal compositions comprising mutant toxins with a new or broadened insecticidal spectrum, and insecticidal compositions comprising polynucleotides encoding the modified Cry4Ba proteins.

Abstract: The subject invention pertains to the use of peptide fragments of cadherins (including cadherin-like proteins). The subject invention includes a cell (and use thereof) comprising a polynucleotide that expresses the peptide fragment. The subject invention includes methods of feeding the peptides to insects. In preferred embodiments, the peptides are fed to target insects together with one or more insecticidal proteins, preferably (but not limited to) B.t. Cry proteins. When used in this manner, the peptide fragment can not only enhance the apparent toxin activity of the Cry protein against the insect species that was the source of the receptor but also against other insect species. Preferably, the cadherin is a Bacillus thuringiensis (B.t.) insecticidal crystal protein (Cry) toxin receptor. Preferably, the peptide fragment is a binding domain of the receptor. In some preferred embodiments, the peptide is the binding domain nearest to the membrane proximal ectodomain.