Exploring Genetic, Molecular, Mechanical and Behavioural Methods of Sex Separation in Mosquitoes

Requests from Member States for exploration of the potential of applying the Sterile Insect Technique (SIT) against mosquitoes in area-wide integrated vector management (AW-IVM) programmes continue to increase. However, because female mosquitoes, unlike male mosquitoes, can transmit disease, means to eliminate them from the mass production process are a critical pre-requisite. In addition, not releasing sterile females would increase SIT programme efficiency in view that sterile males can focus only on achieving matings with wild females. Thus mosquito SIT programme efficiency and safety would be considerably enhanced by the development of improved strains for mass-rearing and release. These include strains that: (a) produce only male insects for release and (b) carry easily identifiable markers to identify released males in the field. Although also assessing mechanical, behavioural and developmental approaches, this CRP will primarily explore classical genetic and modern biotechnology techniques, to accomplish female elimination in major mosquito vectors of disease. To the extent that it is possible, these methods will be created with a view to application to a wide spectrum of mosquito species. Major beneficiaries will be operational AW-IVM programmes in Member States that plan to apply the SIT against mosquitoes. By the end of the CRP, methods for developing sexing strains will have advanced and some strains will be available for evaluation. The development and evaluation of such methods through this CRP will have the following tangible benefits for SIT mosquito control programmes:1.) As only the males are needed for the SIT, the production, handling and release costs can be reduced significantly if sexing strains are used.2.) Male-only releases are several-fold more efficient than releases of both sexes. Consequently, when the genetic sexing technology is available SIT programmes are significantly more efficient and therefore more cost effective.3.) Safety of SIT mosquito programmes will be enhanced. Mosquito SIT implementation cannot include the release of sexually sterile biting females. Therefore mosquito SIT requires the exclusive release of sterile males, which is impossible on large scale without genetic sexing strains.