LUBBOCK, Texas — Mosquitoes across Texas are getting more resistant to the common insecticides used by authorities to keep pest populations down, according to a new study from Texas Tech.
“If you have resistance that means [the mosquitoes] are not dying when you do spray for them. You’re applying this chemical, and it’s not effective,” Bianca Rendon, head graduate researcher, said.
The study started four years ago in the Institute of Environmental and Human Health, looked at the mosquito populations in 50 counties across Texas, including Lubbock County.
Of the more than 1,000 mosquitoes they studied, researchers found that over 2/3 of them were resisting the insecticides, indicating that insecticides are becoming less effective in keeping the pests at bay.
More resistance means more mosquitoes that survive. Rendon emphasized that the mosquitoes’ growing ability to overcome the chemicals could lead to an outbreak of more diseases spread by the insect, including the West Nile Virus, St. Louis Encephalitis, the Zika Virus and more.
“You have all these public health diseases that are vectored by mosquitoes … and so you have cases of these [diseases], vector control programs will go out and spray, but the problem is sometimes … it leads to resistance,” Rendon said.
Researchers are still looking for why the pests are learning to resist the chemicals, citing evolution or over spraying as possibilities.
Local experts said they try to switch up insecticides to avoid this issue. Steven Boston with Lubbock’s vector control emphasized that mosquitoes are still a major issue this year, but September’s sudden cold front helped keep the pests at bay for a while.
“We have noticed that our mosquito population has declined, but there’s still that potential of West Nile Virus that could build-up or is out in that population,” Boston said.
However, overall, he said this year, numbers haven’t been lower than years past, but due to the drought, Lubbock has had a “suppressed population” of mosquitoes.
In August, Lubbock County saw its first mosquito test positive for the West Nile Virus and St. Louis Encephalitis. The Health Department said that there had not been a case of the viruses in people in the city, but several other mosquitoes have tested positive since then.
Vector control will continue to spray for mosquitoes in the county regularly until temperatures drop in a few weeks. Both Boston and Rendon urged people to stay alert but not alarmed about mosquitoes and to keep using safety precautions, especially repellant, against the pests who like to breed in containers and standing water.
“Please continue to wear your mosquito repellant. If you have any standing water, if you have any type of water features in your backyard, dump them, clean them. You could actually be helping grow the mosquitoes that your next-door neighbor is concerned about,” Boston said.
“If you have a flowerpot or a bucket in the backyard, you get rain or water, and it fills up, and it just stays there, stagnant, you’re going to see more mosquito populations. If you help control it at the homefront, then vector control doesn’t have to spray as much, and the resistance doesn’t develop,” Rendon said.