Widespread
conversion of ag land to habitat and the state’s budget shortfall are
combining to clobber mosquito control efforts. One result could be increased
health hazards.
Widespread
conversion of ag land to habitat and the state’s budget shortfall are
combining to clobber mosquito control efforts. One result could be increased
health hazards.
Dave Whitesell, manager of the Colusa Mosquito Abatement District, said the conversion of farmland to wetlands and other forms of habitat is producing vastly larger numbers of mosquitoes.
At the same time, the district expects to lose 22 percent of its $238,000 annual budget from a state shift of funds to education. Whitesell said the budget cut would simply mean a reduction in control work at a time when mosquito populations are mushrooming.
Aside from the discomfort that results from more mosquitoes and less control is the potential for outbreaks of vector borne diseases such as encephalitis and malaria.
Kenneth R. Townzen, supervising public health biologist for the State Department of Health Services, said there is an additional threat on the horizon. "We are concerned about the possible migration of the West Nile virus, which arrived in New York in 1999 and has now reached Louisiana," he said. "It has been pretty devastating on the East Coast during the last three years," he added. Townzen noted that all three of the mosquito borne diseases can be fatal. Victims of the West Nile disease include people, horses, blue jays, crows, mallards and Canada geese. "One indication of the presence of West Nile disease is discovering large numbers of dead crows," Townsend said.
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| Kenneth R. Townzen, above left, and Dave Whitesell see increased health risks from conversion of ag land to wetlands and other habitat. |
The health official said the steadily increasing amount of wetlands in the last 10 years has been reflected in a corresponding explosion of mosquito population. A contributing factor also is the conversion of land inside the levees to wooded habitat. "Last year was the worst for mosquito production that I’ve seen," he said.
Townzen said that wetlands produce "day biters," which cause problems for workers in orchards and tomato fields. "Some workers are afraid to go into the fields because there are so many mosquitoes." Rice fields produce mosquitoes that bite in the evening and at nighttime, but they produce much fewer of the insects than wetlands, he said. Dip tests show about 1 mosquito larva in every five samples in rice fields, compared to more than 100 larvae per sample from wetlands. "I am confident that the increase in wetlands acreage is the reason we are seeing more mosquito production," he said. "The proposal for transitory storage, or temporary storage of flood waters on farm lands, also could be a major mosquito producer."
The Abatement District covers 140 square miles of Colusa County and 20 square miles of Sutter County’s Butte Sink. In an effort to help reduce mosquito populations, the district is asking duck clubs to help pay to reduce the problem. "As a last resort, the district’s Board of Directors could use authority given under the State Health and Safety Code to impose mandatory payment of abatement costs," Whitesell said.
"It is illegal to produce large numbers of mosquitoes," he said. "The code enables the district to call producers in to determine if they are causing a public nuisance. They can be charged abatement costs, plus $500 a day. We hope to avoid that approach."
The creation of habitat and wetlands introduces the public safety and public health risks that are unacceptable. Rural communities continue to carry the larger burden for habitat and wetlands creation.