Disclosed are novel synthetically-modified B. thuringiensis chimeric crystal proteins having improved insecticidal activity against coleopteran, dipteran and lepidopteran insects. Also disclosed are the nucleic acid segments encoding these novel peptides. Methods of making and using these genes and proteins are disclosed as well as methods for the recombinant expression, and transformation of suitable host cells. Transformed host cells and transgenic plants expressing the modified endotoxin are also aspects of the invention.