Bug Busters : Mosquitoes: A tiny fish that feeds on the bloodsuckers will soon be available free of charge to Valley residents. The annual war against the insects begins next month.

This is the desert, not the bayou.

But even in arid Southern California, mosquitoes can be pests. And with the extraordinary rainfall of recent months, it’s a fair bet to expect to see--and feel--even more of the whining little bloodsuckers this spring and summer.

So officials from Los Angeles County’s largest mosquito abatement district are gearing up for their annual war against the area’s 11 varieties. On Thursday, they began trapping hundreds of the tiny green-and-silver fish that actually like mosquitoes.

For breakfast.

The gambusia affinis, or mosquito fish, is one of the most effective weapons used by the Southeast Mosquito Abatement District, and it is available at no charge to San Fernando Valley residents bugged by the menacing drone of the insects.

Later this month, the fish will be available at the abatement district’s North Hollywood office at 12741 Saticoy St.

Mosquitoes like to breed in standing water--the very environment the gambusia affinis also favors, making places such as horse troughs and drainage basins watery lunch counters for the ravenous fish. On warm days, which give gambusia the munchies, a hungry fish can devour several hundred mosquito larvae.

The fish, which grow to a maximum size of about two inches, are a low-maintenance, organic pest-control measure. Related to guppies, they tolerate murky pond water and need no special care, said LuAnn Munns of the abatement district.

When there are no mosquito larvae around, the fish snack on other things, including each other. “These fish are cannibalistic,” Munns said. “But I don’t know if you want to mention that because it kind of turns people off.”

If enough males and females survive, they can reproduce and increase their numbers.

The mosquito season in Southern California runs from April to November. Aside from being downright pesky, the mosquitoes can carry St. Louis encephalitis, which can cause headaches, flu-like symptoms and, in extreme cases, coma and death.

The worst year for St. Louis encephalitis in recent times was 1984, when 16 people came down with the disease in Los Angeles County and one died. Since 1986, only two cases have been reported, but each year county health officials, to reduce the disease threat, warn residents to eliminate stagnant pools of water--such as in old tires and trash cans--where mosquitoes can breed.

Over the next several weeks, mosquito abatement workers will dump thousands of the fish into ponds at Hansen Dam and the Sepulveda Basin. During the rest of the year, the fish live unmolested in golf course ponds around the county.

“They just sit there and happily reproduce until we need them, when we just go out and scoop them up,” Munns said.