Conventional insecticides, such as DDT, kill mosquitoes as soon as they are exposed to the chemical, but their indiscriminate action speeds up the evolution of the insect towards insecticide resistance.
In particular, because the insecticides act on female mosquitoes before they lay eggs, this causes intense selection pressure towards insecticide-resistant females who then pass on this resistance to their offspring.
The research team led by Stephen Gourley used mathematical models to predict the effect of an insecticide that only acts after a time delay, once the mosquitoes have laid their eggs.
Because this results in a much lessened selection pressure on resistant mosquitoes, the team discovered that resistance evolves much more slowly with this type of insecticide.
The strategy aims to exploit the fact that mosquitoes only become able to infect humans with malaria late in their lifetime, due to a relatively long latency stage.
This means that the delayed action insecticide does not result in increased infection rates while the younger insects remain alive.
The technique could result in improved malaria control in areas where resistance to current insecticides is rife amongst mosquitoes.
Gourley said there is a trade-off between effective prevention of malaria transmission by mosquitoes and having to live with mosquito bites involving no malarial transmission.