Mauritius: The Ministry of Health and Wellness proceeded to launch 200 autodissemination lethal ovitraps in the context of the prevention against Dengue Fever this morning in Roche Bois. The traps will be set up in the yards of householders and private and public institutions in Roche Bois in the coming days.
This prevention method, evaluated by the Vector Biology and Control Division in 2020, was very effective in suppressing the Tiger mosquito population. This initiative is an additional vector control measure aimed at further decreasing the incidence of the Tiger Mosquito in areas where several dengue cases have been detected. These traps will also be deployed in other dengue-hit localities in the ensuing weeks.
The trap consists of a black container with a solution of pyriproxyfen, an insect growth regulator. It will help control the Tiger mosquito population in several ways, namely: imbibing female mosquitoes coming to lay eggs in the trap with the pyriproxyfen solution, which will shorten her lifespan from one month to one week, and eggs laid by mosquitoes in the pyriproxyfen solution will not develop into an adult mosquito.
Moreover, this method will considerably reduce the proliferation of Tiger mosquitoes before dying; female mosquitoes will lay eggs in other places, including stagnant water in closed yards and other inaccessible or undetectable places. While laying her eggs, the females will contaminate those stagnant waters with the pyriproxyfen solution from her body, preventing mosquito eggs and larvae present from developing into adult mosquitoes.
An autodissemination lethal ovitrap consists of a container with a solution of larvicide or an Insect Growth Regulator that will impregnate female mosquitoes coming to lay eggs in it. The contaminated female will not die immediately but will visit and disperse the product to other breeding sites before dying.
According to research, autodissemination lethal ovitraps can overcome the limitations of traditional control methods by targeting cryptic or logistically inaccessible larval habitats.
Autodissemination is, in fact, a vector control method that uses a ‘pull’ (attraction and transfer) and ‘push’ (dispersal and transfer to target habitats) technology. It involves the contamination of insects with a biological or chemical insecticide and the subsequent horizontal or vertical transfer of lethal concentration of the product to other insects via mating, oviposition, aggregation, and other behaviours.