Here's an article today in the San Francisco Chronicle about the mosquito fish
SD County needs more fish to fight West Nile virus
07-11) 10:44 PDT San Diego, CA (AP) --
Fish that munch on the larvae of mosquitoes that can carry the West Nile virus are in short supply in San Diego County.
The mosquito fish, a type of small freshwater fish, have been late to breed this year, said John Riggs, the county's supplier in Barstow.
Earlier this year, the county ordered 425 pounds of the fish for $15,000 to release in standing water, where female mosquitoes lay their eggs.
Riggs expects to fill the county's order by early August.
A total of 72 birds in the county have been infected with the West Nile virus, compared to six at this time last year, said county vector control program manager Kerry McNeill.
Mosquitoes can spread the disease to birds, horses and people.
McNeill said residents concerned about standing pools of water that attract mosquitoes should call vector control.
Members of the county's 21-person environmental health team will then visit the site and decide how many fish will be used.
The fish are especially in demand for ponds and abandoned swimming pools on foreclosed properties.
In previous years, county officials obtained enough mosquito fish to supply nurseries, pet stores and aquariums, which then distributed the fish to residents, McNeill said.