I was distressed to read that Science News thinks there are no steroid hormone receptors in insects. Granted, their reproduction is not regulated by steroids, but ecdysone, the molting hormone, is certainly a steroid. There is some evidence that juvenile hormone, the hormone that regulates development and sometimes reproduction, acts through a steroidlike-receptor pathway. Other developmental regulators like retinoic acid and thyroid hormone also work through steroidlike receptors. Perhaps the early evolutionary steps the article seeks are in the invertebrates after all. Elaine Roberts
Colorado State University
Fort Collins, Colo.