Mosquito-borne diseases represent a major threat to humankind. Recently, the incidence of malaria has stopped decreasing while that of dengue is increasing exponentially. Alternative mosquito-control methods are urgently needed. The sterile insect technique (SIT) has seen significant developments recently and may play an important role. However, testing and implementing SIT for vector control is challenging, and a phased conditional approach (PCA) is recommended, that is, advancement to the next phase depends on completion of activities in the previous one. We herewith present a PCA to test the SIT against mosquitoes within an area-wide-integrated pest-management programme, taking into account the experience gained with plant and livestock pests and the recent developments of the technique against mosquitoes.The Need for a PCA to Manage Mosquito Populations Using SIT According to the World Health Organization (WHO), 17% of infectious diseases are vectorborne, leading to more than 700 000 deaths annually [1]. Mosquitoes account for a large part of these diseases of which malaria, dengue, and Zika are the most devastating. After a period of success in global malaria control in the past decades, no significant progress was made in the period 2015-2017, with an estimated 219 million cases in 2017, due to various threats including the spread of insecticide resistance of the mosquitoes hampering current control strategies [1]. In addition, dengue incidence has increased dramatically, with yearly new infections estimated at 390 million. Zika epidemics in 2015-2016 had dramatic effects in Latin America, and this disease still poses a major threat to human health [2]. Increased concerns about the impact of insecticides on living organisms and ecosystems is driving a growing number of countries to reduce the number of approved active chemicals and overall broad-spectrum insecticide outdoor applications. The resistance of mosquitoes to pyrethroids, the most commonly used class of insecticides, continues to increase. The WHO expresses the urgent need for alternative mosquito-control methods that should be added to existing tools, particularly against Aedes spp. [3].Many alternative methods are being tested [4][5][6]. Among those methods, the sterile insect technique (SIT) (see Glossary) is an environment-friendly control method which has been used with great success against other insect pests; for example, the New World screwworm, Cochliomyia hominivorax, has been eradicated from Northern and Central America [7]; the tsetse fly Glossina austeni from Unguja Island, Zanzibar since 1997 [8]; the Mediterranean fruit fly, Ceratitis capitata, from Mexico and the programme is still ongoing to contain its reinvasion from Guatemala [9]; and the codling moth, Cydia pomonella, has been suppressed using SIT in British Columbia, Canada, for more than 25 years [10]. The development of SIT against mosquitoes has progressed rapidly in recent years with significant advances made with the development of genetic sexing strains [11-13], mass-re...