Promotes colloidosmotic lysis by binding to the midgut epithelial cells of Coleoptera. This protein is not toxic in its natural form. It is highly toxic to Colorado potato beetle larvae after an in vitro solubilization and trypsin activation step. The crystal protein is produced during sporulation and is accumulated both as an inclusion and as part of the spore coat. Toxic segment of the protein is located in the N-terminus. Belongs to the delta endotoxin family.