Compositions and methods for controlling plant pests are disclosed. Inparticular, novel nucleic acid sequences encoding modified Cry3A toxins havingincreased toxicity to corn rootworm are provided. By inserting a proteaserecognition site, such as cathepsin G, that is recognized by a gut protease ofa target insect in at least one position of a Cry3A toxin a modified Cry3Atoxin having significantly greater toxicity, particularly to western andnorthern corn rootworm is designed. Further, a method of making the modifiedCry3A toxins and methods of using the modified Cry3Anucleic acid sequences,for example in microorganisms to control insects or in transgenic plants toconfer protection from insect damage, and a method of using the modified Cry3Atoxins, and compositions andformulations comprising the modified Cry3A toxins,for example applying the modified Cry3A toxins or compositions or formulationsto insect-infested areas, or to prophylactically treat insect-susceptibleareas or plants to confer protection against the insect pests are disclosed.
