A transgenic alternative to the sterile insect technique for pest control has been proposed by a collaboration of researchers in the UK. The conventional insect control method, developed in the 1950s, involves the breeding of a large population of sterile males, which are then released into the wild to compete with fertile males for mates, thus depleting populations. Unfortunately, the process of rearing huge numbers of insects and separating them by sex has restricted the utility of the approach. Using transgenic techniques to address these problems, Luke Alphey and his colleagues have created a tetracycline-inducible transgene system that reliably kills Drosophila females unless the insects are fed the antibiotic. In the absence of tetracycline, expression of a gene controlled by a female-specific enhancer leads to the induction of a toxin gene. The flies can be raised and bred normally on medium containing tetracycline, but are unable to produce viable offspring in the absence of the antibiotic. As the system does not require raising the flies to adulthood for sexing, it should significantly simplify the sterile insect technique. Having proved the concept in Drosophila, Alphey is working to adapt the system to “the medfly and the yellow fever mosquito.” The findings are described in Science (287, 2476–2478, 2000).