Development of genetic control in the tomato leafminer, Tuta absoluta

Abstract: Since the arrival in 2006 of a new tomato pest moth, the tomato leafminer (Tutaabsoluta), European tomato growers have suffered significant losses. Furthermore, restrictions totheir choice of pesticides have made control of this moth extremely difficult. Pesticide-freecontrol methods, including natural predators and pheromone, are increasingly sought-after. Anew chemical-free pest control method is being developed in T. absoluta, with the aim ofproviding another control option available to growers. This technique, called RIDL, is a variantof the sterile insect technique, in which a pest insect is mass-reared, sterilised by irradiation, andmass-released over an area infested by their wild counterparts. RIDL improves on this concept byavoiding the requirement for irradiation, so insects are likely to be more competitive in the field.Improved insect performance translates to improved efficiency of pest control. Avoidance ofirradiation also means that the scale and location of a control programme is not restricted to thosethat would justify investment in a costly irradiation facility. This extends to protected crops,which would benefit from this more flexible technology. SIT and RIDL work best in settingswhere immigration and emigration of a pest is low. Protected cultivation, especially ingreenhouses, inherently provides this by restricting movement of the pest. Here, we describeRIDL and how we plan to apply it to T. absoluta and other pests, with particular reference toprotected crops.