Published in Nature Communications, a study led by researchers at Liverpool School of Tropical Medicine (LSTM) in collaboration with the University of Crete identified a molecular pathway that mosquitoes could use to develop resistance while they are still fully susceptible.

Resistance is usually only detected in mosquitoes once it has become established, which is often too late to protect vector control tools that prevent the spread of diseases such as malaria.

LSTM’s researchers have developed a new technique called ‘predictive chemoproteomics’, which monitors the interactions between enzymes in mosquitoes and insecticides. Using special chemical probes as ‘bait’, they were able to identify the enzymes in one kind of mosquito, Anopheles gambiae, that could make it resistant to certain widely used insecticides in future.

In follow-up tests, scientists from LSTM and the University of Crete engineered mosquito strains that produced higher levels of one key enzyme that was identified as having the potential to cause resistance, known as Coeae6g. These experiments confirmed that this enzyme can indeed make mosquitoes resistant to many commonly used insecticides, including pirimiphos-methyl, malathion, bendiocarb, and permethrin. This helps explain why simply rotating insecticides may not prevent resistance.

Dr Hanafy Ismail, senior author, Lecturer in Vector Biology and head of the Chemical Biology Group at LSTM, said: “Until now, we’ve been reacting to resistance after it appears. Our work shows we can spot early warning signs and predict how mosquitoes might survive insecticides before resistance spreads. By spotting hidden risks early, malaria programmes can avoid using insecticides that mosquitoes are already poised to withstand. This is a shift toward smarter, proactive control.”