Biological control escalates mosquito battle

CLOVIS, Calif. (KFSN) -- Controlling the spread of a mosquito which can carry yellow fever and dengue has been very difficult. The mosquito can now be found in Fresno, Clovis and Madera, so the fight has escalated to a new level of biological control.

Those pesky mosquitoes won't let up. Denise Hensley and her husband always put on repellent when they go outside to keep the bugs away. Hensley said, "Last year and the year before it seems like it was a lot of mosquito bites."

Some 6,000 mosquitoes were unleashed into a Clovis neighborhood near Magnolia and Scott. An unpleasant thought until you consider they're all male. Only the females bite because they need your blood to produce eggs.

Consolidated Mosquito Abatement District Manager Steve Mulligan said, "This is new novel strategy. It hasn't been tried anywhere."

The fight against Aedes aegypti rides on cardboard tubes holding male mosquitoes seeking females. They were shipped from the University of Kentucky. Mulligan explained, "They're dusted with a very minute amount of insecticide that kills mosquito larvae, young mosquitoes."

The mosquito busters spread out in a neighborhood where the pest has been found. The male mosquitoes will transfer the insecticide to the females when they mate. Scientific Technical Services Director Jodi Holeman said, "When the female has it, she can then deposit it into these different water sources where she's laying her eggs. Thus, treating that particular water source and killing any immatures that might be in that water."

Yellow fever mosquitoes lay eggs in tiny containers and even drainage pipes. Mulligan pointed out, "A lot of these waters, containers or sources of water are difficult to find. They're hidden sources."

This method of biological control takes the fight straight to the breeding ground. Holeman said, "It's very frustrating to not see a reduction in those numbers, which is why we're trying something different. Something new. Something we hope will really make a difference."

Nationwide, all eyes are on Clovis to see if this method works, though it will take a few months to kill off the next generation.