Genetically ‘sterile’ insects in pest control programmes for public health and agriculture: Current status and future prospects

Abstract: New tools are urgently needed to help control insect pests of economic importance inthe fields of both agriculture and human health. Building on the well understood Sterile InsectTechnique (SIT), which has been used successfully for agricultural insect pest control for over 50years, recent advances in insect genetic engineering can now provide novel solutions for effectivepest control in both agriculture and public health. SIT uses repeated releases of sterile maleinsects to mate with a target female population but no progeny survive from these matings,thereby causing the population of the wild insects to decline, hopefully to either below aneconomic or disease transmission threshold or to local elimination.Oxitec Ltd, a British SME is pioneering the use of genetic sterility in insect species and hasdeveloped strains of insects that express dominant lethal genes and are genetically “sterile”,unless supplied with a repressor molecule in the diet. Insect strains have been developed for usein public health (Aedes aegypti and Aedes albopictus) and agricultural pest control programmes(Pectinophora gossypiella, Plutella xylostella, and the Tephritid fruit flies Bactrocera oleae,Ceratitis capitata, and Anastrepha ludens). Future projects include extending the techniques totomato leaf miner (Tuta absoluta) and the Anopheline mosquito malaria vectors.The phased testing of GM insects is on-going with several insect strains tested byindependent collaborators in a variety of conditions, ranging from the laboratory, semi-field testsand open field releases. The regulatory pathway for these insects will be described, along withneed for context specific community engagement. Consideration will also be given as to howthese “sterile” insect strains might be used in an Integrated Vector Management (IVM) orIntegrated Pest management (IPM) system.