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

Abstract

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.

Operational Parameters for the Aerial Release of Sterile Codling Moths Using an Uncrewed Aircraft System

“…The results presented here support this finding. Bouyer et al [41] found decreased recapture when insects were released at 100 m compared to 50 m. The difference between Bouyer et al's [41] findings and those presented here may be because a smaller insect, with a lower terminal velocity, was released from a greater altitude and, consequently, may have experienced greater influence due to wind and/or drifting outside the study area.…”

“…This study is not the first comparison of aerial and moving ground release methods, but it contributes to our understanding of aerial and moving ground release for sterile, adult Lepidoptera. Other studies have described aerial release methods [23,32,[39][40][41][42][43] and ground release methods [18,44] and have compared the releases of different life stages concurrently with different release methods [45,46]. Static ground release, moving ground release, and aerial release have all been examined to release sterile adult codling moths in BC, Canada [28,31,47], though moving ground release has been the method employed by the OKSIR program since 1994 [8].…”

“…One might expect that insects released from high altitudes would experience greater damage when they impact the ground. Though the terminal velocity of C. pomonella is unknown, terminal velocities of smaller (Aedes aegypti = 2.5 m/s) and larger (Ceratitis capitata = 3-4 m/s) sterile insects have been reported [41,55]. At the range of fall speeds reported, a terminal velocity of falling codling moths would be reached in the first 10 m of descent from aerial release [46], and it is unlikely that release from any altitude above 10 m would have an increased effect on moth quality when they reached the ground.…”

Irradiation induced inversions suppress recombination between the M locus and morphological markers in Aedes aegypti

“…and b) the linkage of the phenotypic marker to the sex-determining genetic locus [28]. There is a renewed interest in revival and application of SIT for mosquitos [24,[29][30][31], as evidenced also by recent advances in refinement of irradiation doses and drone-mediated releases in the field as well as the recently published guidance framework and phased conditional approach for testing the SIT against Aedes mosquitoes [32][33][34]. Such strategies will be greatly facilitated by the availability of GSS developed through classical genetics, since there is documented efficiency through time and wide public acceptance [35].…”

Assessment of a Novel Adult Mass-Rearing Cage for Aedes albopictus (Skuse) and Anopheles arabiensis (Patton)

“…Successful implementation of such projects relies on ensuring high levels of mosquito production and repeated releases of sterile males in overflooding numbers [25] that outcompete their wild counterparts within the target area [11,19]. To meet these requirements, novel methods and equipment including automatization of processes for the mass-rearing, sex separation, and release of mosquitoes are under development for deployment in the field [26]. Optimization of the mass-rearing conditions to produce eggs requires continuous efforts to achieve economic efficiency and high production rates.…”