The invention relates to identification and characterization of recombinant DNA and polypeptides for specific Bt toxin receptors. In particular, the Bt toxin receptors of the invention include those derived from the Lepidopteran super family including the species Trichoplusiani ni, Pseudoplusia includens, Helicoverpa zea, and Spodoptera frugiperda. The receptors of the invention further include those derived from the Coleopteran super family and particularly from the species Diabrotica virgifera virgifera. The recombinant DNA and polypeptides so provided are useful in the identification and design of novel Bt toxin receptor ligands including novel or improved insecticidal toxins for use in a variety of agricultural applications. Materials and methods for identifying novel toxins are also disclosed herein. The invention also provides methods for selecting toxins to combine to control insect populations by manipulating Bt toxin receptor.