In the first part of the project, a contamination technique was developed to coat sterile male insects with biocide or biopesticide formulations in order to achieve the desired effect of transfer to females without reducing their survival/ quality. This technique is based on impregnating chilled insects with a powder formulation.
We then tested several formulations of pyriproxifen, strains of Densovirus and entomopathogenic fungi in the laboratory and in semi-field trials before selecting the best candidates for the field trials. Based on the laboratory results, models predicted that boosted SIT could reduce the number of sterile males required to reduce Aedes vector populations and control dengue epidemics by more than 95% compared to SIT. More complex models integrating a spatial component and meteorological data were developed to compare the efficiency of this control method with other methods in temperate and tropical climates.
We also optimized all mass-rearing and irradiation protocols for Aedes mosquitoes, and tested an aerial drone-release system in the field, allowing homogeneous releases of sterile male mosquitoes without reducing their quality. The release system has been patented worldwide and validated in the field in both rural and urban settings.
Genetic sexing systems based on fluorescent markers inserted into the sexual loci of Aedes mosquitoes have been developed. They allow sorting female from males at the L1 stage in both Ae. albopictus and Ae. aegypti. We investigated the potential of these strains as an operational sexing tool using a COPAS sorter at a small scale. Two sexing options were proposed, one based on the release of fluorescent transgenic males and the other of non transgenic males, using a crossbreeding scheme.
We have participated in several expert groups to implement risk analyses on genetic control of mosquitoes, including SIT, and have obtained all the authorisations to run pilot field trials of boosted SIT against Aedes albopictus and Ceratitis capitata (medflies) in the Valencia region, Spain, and against Aedes aegypti in Reunion island, France. The strategy was also transferred to an elimination project targeting Glossina palpalis gambiensis (tsetse) in the Dakar region of Senegal. All of these trials were successful in reducing target populations and the results are still being analysed.
Finally, an acceptability study has been conducted with the aim of reflecting, beyond the mere need for cutting edge research and development, the deep interweaving of technology, science and society.
The results were presented at 10 international conferences and 5 press releases were conducted.
