Peri-domestic vector control interventions using attractive targeted sugar baits and push-pull strategies

Great challenges to sustained malaria and arbovirus control remain, including transmission by vectors that occur outdoors or outside of sleeping hours, the enormous scale of larval breeding in urban centres and the failure of people to comply with vector control. Furthermore, developing insecticide resistance, shifts in vector dominance and behaviour emphasises the need for new integrated vector management strategies. Behavioural aspects of the mosquitoes' lifecycle, such as mating, oviposition, sugar- and host-seeking, are influenced by olfactory cues in the environment. This chapter focuses on two new technologies that are in development for targeted vector control in and around the home that require minimal compliance from users. Both technologies exploit specific olfactory mechanisms in mosquito genera that could unlock the potential for highly targeted vector control interventions. Attractive targeted sugar baits (ATSB) exploit mosquito sugar-feeding behaviour to deploy insecticides. They use an attractive scent as an olfaction stimulant and a sugar solution as a feeding stimulant mixed with an oral insecticide to induce mosquito mortality upon ingestion. ATSB methods may be deployed as a stand-alone method or integrated with other interventions. They are technologically and operationally simple, low-cost and effective across all major mosquito genera. A major benefit of ATSB is that it targets and kills male and female mosquitoes on emergence from breeding sites and multiple contact points throughout the mosquito's lifetime, increasing the likelihood of reducing the mosquito's lifespan, and thus, its probability of transmitting disease. Push-pull systems exploit mosquito host-seeking behaviour using a combination of spatial repellents and lure and kill strategies to push mosquitoes away from the home or the peridomestic space and into traps that mimic vertebrate hosts. At the moment, the greatest limitation to push-pull systems is the need for CO2 to attract mosquitoes. Most of the current trials have shown that efficacy of the push-pull strategy is primarily reliant upon the push unit, with only marginally improved efficacy with the addition of the pull unit. This finding could potentially be due to the size of these studies, because community-level protection from malaria using removal trapping has been demonstrated.