The IAL-PID2 cells derived from imaginal wing discs of the last larval instar of Plodia interpunctellawere responsive to 20-hydroxyecdysone (20E). These imaginal cells respond to 20E by proliferative arrest followed by a morphological differentiation. These 20E-induced late responses were inhibited in presence of juvenile hormone (JH II). From these imaginal wing cells, we have cloned a cDNA sequence encoding aP. interpunctellaecdysone receptor-B1 isoform (PIEcR-B1).