Field performance of sterile male mosquitoes released from an uncrewed aerial vehicle

Genetic control methods of mosquito vectors of malaria, dengue, yellow fever, and Zika are becoming increasingly popular due to the limitations of other techniques such as the use of insecticides. The sterile insect technique is an effective genetic control method to manage insect populations. However, it is crucial to release sterile mosquitoes by air to ensure homogeneous coverage, especially in large areas. Here, we report a fully automated adult mosquito release system operated from an uncrewed aerial vehicle or drone. Our system, developed and tested in Brazil, enabled a homogeneous dispersal of sterile male Aedes aegypti while maintaining their quality, leading to a homogeneous sterile-to-wild male ratio due to their aggregation in the same sites. Our results indicate that the released sterile males were able to compete with the wild males in mating with the wild females; thus, the sterile males were able to induce sterility in the native female population. The use of drones to implement the sterile insect technique will lead to improvements in areal coverage and savings in operational costs due to the requirement of fewer release sites and field staff.

Importance of vector-borne infections in different production systems: bovine trypanosomosis and the innovation dynamics of livestock producers in Senegal

In Senegal, a project has been undertaken to eradicate a population of tsetse flies (Glossina palpalis gambiensis) from a prime area for intensifying livestock production--the coastal region of Niayes. The project is intended to remove the constraint of trypanosomosis and allow the ecological intensification of cattle production. A cross-sectional analysis of ten case studies was the inductive phase of an assessment to gauge the impact of removing trypanosomosis on livestock production strategies. The methodology used was comprehensive analysis, with participatory epidemiology tools to understand farmers' rationales. The authors analysed the strategies of three main types of livestock producer (agro-pastoralists, mixed crop/livestock farmers and intensive dairy farmers). The strategies were in line with the farmers' goals and their ability to mobilise the socio-technical network. The risk management of trypanosomosis has been incorporated into livestock management practices through the use of trypanotolerant breeds, medical prophylaxis or placing livestock in low-risk areas. Removing the risk of disease would therefore have a major impact on decisions about the composition and strategic direction of herds. This change in the animal health environment would steer livestock production along different routes of intensification in a highly competitive environment. The indicators of innovation capacity revealed by this study will be used to quantitatively monitor various change scenarios, taking livestock producers' reasoning into account, in order to assess the socio-economic impact of eradicating the tsetse fly population in this area. The methodology presented in the study can be used to understand the impact of controlling other vector-borne infections on the innovation dynamics of livestock producers.