LA County to release sterilized mosquitoes to fight against invasive species
Los Angeles County has launched its latest plan to fight an invasive mosquito species by using what may seem like a counter-intuitive strategy.
"We are targeting a species that's responsible for transmitting some really nasty diseases," Greater Los Angeles County Vector Control District director Steve Vetrone said. "So we're looking for a novel way to aid us in our fight."
The target is the invasive Aedes aegypti mosquito, which is also known as the yellow fever mosquito. The district said the species rapidly spread across L.A. County in the last decade. Scientists hope to stem the growth with their new strategy called sterile insect technique or SIT.
"We use X-ray technology to sterilize male mosquitoes which don't bite and then those will be released out to mate with wild females and this particular species," Vetrone said.
Scientists decided to use this method since the mosquitoes are resilient to common pesticides. They also law their eggs in small hidden water sources in people's front yards, backyards, patios and in other areas where mosquito control agencies can't easily access.
SIT will help reduce the population of these mosquitoes and reduce the possible threat of tropical diseases like dengue fever, chikungunya, zika and others.
"We're looking to try to achieve a ratio of sterile male to wild males in the area of right around seven to ten to one," Vetrone said.
West Valley Mosquito and Vector Control executed this plan in the Inland Empire. The males were raised and sterilized in a lab with X-ray machines like the ones in L.A. County.
The released male mosquitoes cannot bite or spread diseases but can achieve the plan's goals.
"Once that happens, then those males will die," Vetrone said. "Those females mate with one of our sterile males; any sperm she collects, she will then store for all of her batches of eggs. But, if she's mated with one of our sterile males, any sperm that she collects, she will then store for all of her batches of eggs. If she's mated with one of our males, then any of those eggs that she lays will not be viable."
The male mosquitoes will be released within several areas, including neighborhoods like Alpine Village and Sevenhills in Sunland-Tujunga. It's not meant to be an overnight solution but one that vector control has high confidence in moving forward.
"While they may see a few extra mosquitoes flying around, we're not going to be adding to the biting pressure that they're experiencing," Vetrone said. "Hopefully, in the next couple of months, we're going to be reducing that bite. It's going to look worse before it gets better."
The first sterilized male mosquitoes will be released on Thursday. Scientists will continue to release mosquitoes weekly until the end of October. Based on the program's success, the district hopes to expand it to other areas.