Sunday, April 19, 2015
YOLO COUNTY NEWS
99 CENTS

Mosquitofish form first line of defense against pests

MosquitoFish1w

Luz Rodriguez, a staffer at the Sacramento-Yolo Mosquito and Vector Control District, looks at thousands of mosquitofish swimming in a pool at the district's facility in Elk Grove, the biggest breeding ground in the world for the mosquito-loving fish. Sue Cockrell/Enterprise photo

By
From page A1 | June 20, 2014 |

The Sacramento-Yolo Mosquito and Vector Control District wages battle against mosquitoes, defending rural and urban populations from a long list of debilitating diseases. And its No. 1 weapon against the deadliest pest on Earth?

Fish.

Specifically, Gambusia, silver and pinky-finger-sized, that feast on mosquito larvae and other water-laying insects.

The district’s Elk Grove facility is the biggest breeding ground in the world for mosquitofish, as they have been aptly nicknamed; 2.7 million on average are born, grown and deployed each year. “Planting” the fish means fewer pesticides and less manpower are needed to control mosquito populations.

Every day from April to August, field agents load their pickups with 150-gallon fish tanks and deliver the mosquitofish free to rice paddies, abandoned swimming pools and backyard ponds.

A decade or so ago, they tried to drop Gambusia into flooded rice fields from a crop duster, usually used to spread pesticides or seed. It flew as close to the ground as it could, but at 180 miles per hour.

Seventy percent of the fish died, said Tom Hedley the fisheries supervisor.

So, no more airplanes. Technicians now scoop the fish up out of the tank in a net, kneel down and place them gently in the water.

“We try to traumatize them as little as possible,” Hedley said.

Elk Grove houses the biggest mosquito fishery in the world because of the high concentration of rice growers in the Sacramento Valley. The dual-county district was formed when scientists realized that many of the mosquitoes plaguing urban Sacramento were buzzing over from Yolo County.

Then, people were concerned about culix mosquitoes, said Robert Washino, a mosquito expert, professor emeritus at UC Davis and retired 38-year-old trustee of the vector control district. In 1952, the Central Valley suffered an encephalitis outbreak that killed 50 people. Now, folks worry about West Nile virus: So far this season, Yolo County has counted one infected mosquito and four infected birds — three of which were found in Davis.

“And in the last 10 years, we’ve seen the introduction of the aedes mosquitoes, much more urban mosquitoes,” Washino said.

Recently found in the Bay Area and Los Angeles, aedes aegypti mosquito worries public health officials because it can spread dengue and chikungunya viruses. Fish aren’t as effective in cities and neighborhoods, so vector control officers rely more heavily on traps set around the two counties.

Mosquitoes caught in the trap are taken back to the lab in Elk Grove, where they are examined and tallied on a colorful analog machine that resembles a two-tiered children’s xylophone. If the mosquito is a species known to carry West Nile, lab techs grind it into a paste and test for pathogens. Chemicals are deployed only when viruses are found.

Down the hall from the lab, the district raises mosquitoes in addition to fish. The insectary is a stifling, moist room, like summer in Georgia, with white rusting trays full of warm water and, terrifyingly, thousands of mosquito larvae. They look like little sticks, like little dandelion seeds wiggling around in the water, searching for bits to eat so they can grow big, pupate and suck your blood (or that of birds or horses or other animals). Researchers will use them to test pesticide resistance or as learning instruments in classrooms.

But with schools on break, the vector control technicians are in the field full time, delivering hungry fish to still water to gulp down mosquito larvae and keep disease at bay.

— Reach Elizabeth Case at [email protected] or 530-747-8052. Follow her on Twitter at @elizabeth_case

Comments

comments

Elizabeth Case

  • Recent Posts

  • Enter your email address to subscribe to this newspaper and receive notifications of new articles by email.

  • .

    News

    Aggie Pride on parade at UC Davis Picnic Day

    By Wayne Tilcock | From Page: A1 | Gallery

     
    City wants a study of sewer rates

    By Dave Ryan | From Page: A1

    Hard-of-hearing student needs community’s help

    By Anne Ternus-Bellamy | From Page: A1 | Gallery

     
    KDVS fund drive includes on-air pledging, plus parties and food

    By Jeff Hudson | From Page: A1 | Gallery

     
     
    Art helped sell California’s agriculture

    By Special to The Enterprise | From Page: A3 | Gallery

     
    Lawyers seek resolution to Davis molest case

    By Lauren Keene | From Page: A4

    Sign up now for Celebrate Davis!

    By Enterprise staff | From Page: A4Comments are off for this post

     
    Students, families can get after-hours Internet access

    By Enterprise staff | From Page: A4

    Garamendi hosts conference for women

    By Special to The Enterprise | From Page: A5

     
    ‘Invaluable public servant’ retires after 20 years

    By Tanya Perez | From Page: A5 | Gallery

    Your brain’s aging and a new report urges ways to stay sharp

    By The Associated Press | From Page: B5

     
    Injury-proof yourself for effective exercise

    By Special to The Enterprise | From Page: A6

    Understanding risks can help women prevent leading health threats

    By Special to The Enterprise | From Page: A7

     
    Get some advice at Connections Café

    By Enterprise staff | From Page: A8

    Eyewitness speaks about Israel’s election

    By Special to The Enterprise | From Page: A8

     
    Free gardening advice offered

    By Enterprise staff | From Page: A8

    Grad Night tickets on sale online

    By Enterprise staff | From Page: A8

     
    Schenker speaks about ‘Magical Mexico’

    By Enterprise staff | From Page: A8

     
    Yolo County DA honors crime victims at annual tribute

    By Special to The Enterprise | From Page: A8

    Holman offers Publishing 101 seminar

    By Enterprise staff | From Page: A8

     
    Radio-controlled airplanes will race April 25-26

    By Enterprise staff | From Page: A8

    Woodland bike rides set every Saturday

    By Enterprise staff | From Page: A8

     
    Join the 10,000-vegetable challenge!

    By Enterprise staff | From Page: A9Comments are off for this post

    NAMI group offers family support

    By Enterprise staff | From Page: A9

     
    Birding tour will benefit Putah Creek Council

    By Special to The Enterprise | From Page: A10 | Gallery

    Watershed Wonders activities return to Putah Creek

    By Special to The Enterprise | From Page: A10

     
    Yolo County Neighborhood Court seeks new volunteers

    By Special to The Enterprise | From Page: A10

    Two drought-preparedness water bills pass out of Senate committees

    By Special to The Enterprise | From Page: A11

     
    UCD looks at building a better brain as we age

    By Enterprise staff | From Page: A11

    ‘Vault’ highlights ‘Kathak’

    By Enterprise staff | From Page: A11

     
    Picnic Day favorites: dogs, bikes science

    By Wayne Tilcock | From Page: A13 | Gallery

    Strike up the band, and the bubbles!

    By Wayne Tilcock | From Page: A14 | Gallery

     
    .

    Forum

     
    Ready for the parting glass

    By Creators Syndicate | From Page: B5

     
    Leash your dogs; it’s the law

    By Letters to the Editor | From Page: B6

    John Cole cartoon

    By Debbie Davis | From Page: B6

     
    Yolo Crisis Nursery still needs help

    By Our View | From Page: B6

    Drink up, kids, but make your choice a healthy one

    By Special to The Enterprise | From Page: B6

     
    Speak out

    By Debbie Davis | From Page: B7

    Let’s not turn our backs on the Earth

    By Special to The Enterprise | From Page: B7

     
    This Earth Day, make a pledge to cool your home

    By Special to The Enterprise | From Page: B7

    .

    Sports

    Fast Aggie start negated by 14-0 USC lacrosse run

    By Bruce Gallaudet | From Page: B1 | Gallery

     
    Stagnant second-half offense sinks Devil girls

    By Thomas Oide | From Page: B1 | Gallery

    Over the hump? DHS baseball team wins late

    By Spencer Ault | From Page: B1 | Gallery

     
    Lambdin, Marshall lead Aggies at Mt. SAC

    By Enterprise staff | From Page: B1

    Republic FC gets another win at Bonney

    By Evan Ream | From Page: B2

     
    UCD roundup: Aggies sweep a water polo double dip

    By Enterprise staff | From Page: B2 | Gallery

    Busy Clancy, Hall spark Devil tracksters at Mt. SAC

    By Enterprise staff | From Page: B3 | Gallery

     
    Former DHS star Drexel returns to create havoc for Aggies

    By Bruce Gallaudet | From Page: B4 | Gallery

    Pro baseball roundup: Oakland blanks Kansas City

    By The Associated Press | From Page: B14

     
    Sports briefs: Blue Devils split a pair of tennis matches

    By Enterprise staff | From Page: B14 | Gallery

    .

    Features

    .

    Arts

    .

    Business

    Marrone Bio Innovations strengthens its sales team

    By Special to The Enterprise | From Page: A12

     
    New phase opens at Brookfield Cottages

    By Special to The Enterprise | From Page: A12

    Tucos closes; new Japanese, pizza, subs debut

    By Wendy Weitzel | From Page: A12 | Gallery

     
    WISH grant funds available to eligible homebuyers

    By Enterprise staff | From Page: A12

    .

    Obituaries

    Alice Catherine Micheltorena

    By Special to The Enterprise | From Page: A4

     
    Jody Zewe

    By Special to The Enterprise | From Page: A4

    Herman Timm

    By Special to The Enterprise | From Page: A4

     
    Ruth Rodenbeck Stumpf

    By Special to The Enterprise | From Page: A4

    Robert Leigh Cordrey

    By Special to The Enterprise | From Page: A4

     
    .

    Comics

    Comics: Sunday, April 19, 2015

    By Creator | From Page: B8