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

Closed for proposals

Project Type

Coordinated Research Project

Project Code




Approved Date

12 December 2012

Start Date

4 June 2013

Expected End Date

3 June 2018

Completed Date

22 January 2019


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. 


To explore genetic, molecular, behavioural and mechanical methods of sex separation in mosquitoes

Specific objectives

To continue encouraging and attracting participants to the CRP in the field of classical genetics

To explore irradiation and classical genetic approaches for sex separation in mosquitoes

To explore mechanical, behavioral, developmental and symbiont-based approaches for sex separation in mosquitoes

To explore molecular approaches for sex separation in mosquitoes


All specific objectives of this CRP were achieved including the development of genetic sexing stains, using irradiation and classical genetics or molecular approaches, as well as novel sex separation methods (such as the laser-based pupal size sorter). Some of the genetic sexing strains and novel sex separation tools developed were tested under small scale rearing (laboratory) or semi-field conditions. These strains and tools will significantly contribute to the development and implementation of sterile insect technique (SIT) as a component of integrated pest management strategies. The next step is their refinement, if needed, and validation under mass rearing conditions and pilot trials prior to their deployment in large-scale operational programs.


Member States continue to suffer due to dengue, chikungunya, Zika, yellow fever and malaria outbreaks. Conventional methods are neither efficient nor sustainable to control vector mosquito populations, and efficient and cost-effective vaccines and drugs are still lacking. Member States continue requesting the development of SIT-based strategies as component of integrated vector management approaches for the population suppression of mosquito vector species transmitting dengue, chikungunya, Zika, malaria and other major diseases.

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