The development of juvenile hormone (JH) analogues for insect control, and their laboratory and field testing, are now being carried out on an industrial scale. Studies of the hormone action at the cellular level, and of the many implications of JH applications on various stages of the insect life-cycle, are lagging because such studies require long-term scientific involvement. Although many analogues have little specificity for particular insects, the ultimate effects may be very different. Various considerations that may influence the commercial development of JH are discussed.