Southern California officials on Thursday launched an initiative aimed at curbing an invasive mosquito species that has spread rapidly in the greater Los Angeles area during the past 10 years.
The effort includes releasing tens of thousands of sterilized male mosquitoes into the wild to mate with female mosquitoes, according to an April release from the Greater Los Angeles County Vector Control District. The process is called the Sterile Insect Technique, or SIT, and was used by the California Department of Food and Agriculture to control the population of Mediterranean fruit flies in the state. The Orange County Mosquito and Vector Control District is also partnering on the move.
“SIT offers a sustainable and environmentally friendly solution to reduce mosquito populations and ultimately minimize the transmission of diseases,” Steven Vetrone, Vector Control District director of scientific-technical services, said in the release.
The male mosquitoes have been sterilized using X-ray technology, officials said, and the eggs laid by female mosquitoes who mate with the released insects will not hatch, “decreasing the overall mosquito population over time.”
Vetrone told Newsweek over email on Friday that the first batch of sterilized male mosquitoes was released Thursday. The mosquitoes will be released “at a ratio between 7:1 and 10:1 sterile to wild males,” Vertrone added, and the releases will continue weekly until the end of October.
“At the height of the mosquito season, as many as 60,000 males a week might be released depending on wild population estimates in surveillance traps in the pilot area,” Vetrone said.
The mosquito species that scientists are hoping to curb is the invasive Aedes, which is able to transmit diseases including dengue, chikungunya and Zika. Over two dozen counties in California reported the presence of Aedes aegypti, also known as the yellow fever mosquito, as of May 3, according to the state Department of Public Health. Los Angeles and Orange counties also contend with the Aedes albopictus, or the Asian tiger mosquito.
According to officials, cited by KCAL, the Aedes mosquitoes are resistant to common pesticides and often lay their eggs in small hidden water sources in residential yards and patio areas, which are hard to reach by control agencies.
The sterilized mosquitoes are being released into two Sunland-Tujunga neighborhoods under the SIT program. Vetrone said in the April release: “While the introduction of male mosquitoes may lead to an increase in noticeable overall insect presence, residents should be able to notice a reduction in biting activity,” as male mosquitoes do not bite.