On top of COVID and the flu, we’re now in the heart of the West Nile season. So far this year, more than one-dozen Texas counties have reported a trace of West Nile. A new study done at Texas Tech shows that mitigation efforts are falling short. Steve Presley, who heads the institute of environmental and human health, tested to see if insecticides were working on mosquitoes. He says mosquitoes have been building up immunity to the insecticides because some Texas counties use the same ones, year after year. He says the study shows how important it is to switch it up from season to season.