Delayed effects of juvenile hormone on insect metamorphosis are mediated by the corpus allatum

EXPOSURE of insect embryos to juvenile hormone or to any of its analogues can result in delayed effects which are realized later at metamorphosis1–5. These have been attributed to: (1) persistence of the applied hormone through larval life2; (2) interference with the overall programming of the embryo for postembryonic development1,3; and (3) the selective interference with the embryonic programming of the corpus allatum3,5,6. This study presents evidence that juvenile hormone disrupts the embryonic programming of the corpus allatum such that it does not cease secretion of the hormone as a prelude to metamorphosis.