FRIDAY, Jan. 23, 2004 (HealthDayNews) -- A species of mosquito that spreads the West Nile virus has shown the first signs of resistance to pyrethroid insecticides, says a California study in the current online issue of Pest Management Science.
The resistance was detected in a population of Culex pipiens complex mosquitoes breeding in pools of water below ground, beneath an apartment. The researchers couldn't determine whether these below-ground mosquitoes breed with above-ground mosquito populations.
If they do, that raises the possibility they might spread their pyrethroid resistance.
This kind of resistance has been detected among mosquitoes of the same species in Africa and Asia. But this is the first time it's been reported in North America.
Pyrethroids are commonly used agricultural pesticides.
Here's where you can learn more about West Nile virus.