Our research looked at whether releasing Oxitec flies, which are genetically engineered so that only male fly offspring survive, could provide a better alternative. The genetically engineered flies are not sterile, but they are only capable of producing male offspring after mating with local pest females - which rapidly reduces the number of crop-damaging females in the population. Using this method means that the males do not have to be sterilized by radiation before release, and we have shown they are healthier than the flies traditionally used for SIT.