Transposable elements such as P, hobo, Hermes, mariner and Mines have been successfully harnessed as gene vectors to achieve the transformation of several dipteran species including Drosophila melanogaster, Ceratitis capitata and Aedes aegypti, Plasmid-based excision and transposition assays have been useful indicators of an element's ability to be mobilized in vivo and thus potentially serve as a transforming vector, We report that the transposable element piggyBac is capable of precise excision and transposition in the pink bollworm (Pectinophora gossypiella), a worldwide pest of cultivated cotton. Combined with a suitable marker gene, the piggyBac element may serve as a vector for germline transformation in this and (potentially) other lepidopteran species.