“Letting thousands of mosquitoes go isn’t something we typically do,” said Jodi Holeman, the scientific-technical services director with the Consolidated Mosquito Abatement District.
But that’s exactly what she and her team have been doing for the past month.
In what district manager Steve Mulligan calls “a novel strategy,” the mosquito abatement workers have released about 10,000 male mosquitos per week in a Clovis neighborhood.
I am in 100 percent support of this project.”
Abel Pangan, Clovis resident
“All other ways we’ve tried to control this invasive species of mosquito, aedes aegypti, have failed, so we are collaborating with the University of Kentucky in this project,” Mulligan said. “We are using the mosquito against themselves. The objective is to release the males, which are dusted with insecticide, so that they will go and mate with the female mosquitoes in this neighborhood and deposit that insecticide into containers of water where the eggs are laid.”
Residents in the test neighborhood are happy to have the mosquitoes released in their side yards — male mosquitoes don’t bite.
“I am in 100 percent support of this project,” said Abel Pangan, who was watering plants in his front yard while the mosquito abatement team released the insects outside nearby houses. “This will be very helpful to the community. Every summer we have (mosquitoes) and I have to be really careful if I come outside in the late afternoon.
“Mosquitoes, they love me! I think my blood is very tasty for them because when we are outside I am the one who gets bit first.”
Pangan’s neighborhood — just north of Shaw Avenue and west of Temperance Avenue — was chosen because abatement personnel detected Clovis’s first aedes aegypti population there in 2013.
“This is the third year that residents have been dealing with aedes aegypti,” Holeman said. “A lot of people can’t even enjoy going out into their backyards. We work to eradicate the mosquito population, at least to bring the level down to one that’s tolerable for residents.”
The team collects eggs from the insect’s population in that specific neighborhood and sends them to the University of Kentucky where they are reared and dusted with insecticide and dye.
Aedes aegypti can grow from an egg to an adult in approximately seven days, and they can survive as adults for several weeks, Holeman said.
The adult males are then shipped back to Clovis in tubes. Along with 1,000 insects, a tube holds a cotton ball soaked in sugar water for the mosquitoes to feed off of while travelling.
“Only female mosquitoes need blood to breed, that’s why they are the only ones to bite us,” Holeman said.
Twice a week for four weeks, the team has released six tubes worth, or about 12,000 mosquitoes. They gently tap and blow on the tubes to encourage the males to fly out, then let the tubes rest upright in a cup for several minutes to allow reluctant mosquitoes to venture off.
It prevents the next generation — prevents the immatures from reaching the adult stage — but it doesn’t do anything to the adults that are currently flying.”
Jodi Holeman, Consolidated Mosquito Abatement District
Any that remain in the tube, because they don’t want to leave or because they’re dead, are transferred to a petri dish and taken back to the lab to be counted.
“So we release 12,000, but with the mortality rate, we’re actually releasing closer to 10,000 per week,” Holeman said.
Water sources have been placed around the homes as well, and the team tests the water weekly for insecticide, which would indicate that the males are infecting the next generation of their breed with poison.
Water dishes in a nearby “control” neighborhood are also being tested.
The team hopes that data collected over the next week or two will show that their eradication method is working.
“It’s a delayed observation… it prevents the next generation — prevents the immatures from reaching the adult stage — but it doesn’t do anything to the adults that are currently flying,” Holeman said.
Neighboring mosquito abatement agencies have sent team members to watch the releases each week “out of sheer interest,” Holeman said. “Usually we’re trying to capture and kill. We don’t release mosquitoes.”
If the Consolidated Mosquito Abatement District’s novel strategy works, it would be a big win for humans against the invasive insect.
And it would be a huge benefit to Clovis residents.
“They just want some relief from this mosquito,” Holeman said.
Aedes aegypti, also known as the yellow fever mosquito, originated in Africa but has spread to other parts of the world, including California. The mosquito can be recognized by white markings on its legs and a marking in the form of a lyre on the thorax.
Aedes aegypti is a vector for spreading tropical fevers and other diseases.
The Consolidated Mosquito Abatement District is working to control the aedes aegypti mosquito population through a partnership with MosquitoMate, the University of Kentucky, and University of California, Davis. Residents with questions can visit www.mosquitobuzz.net or call the district office at (559) 896-1085.