Monday, May. 17, 2010
Officials: Perfect year for mosquitoes
By Charles Guest / Special to The Enterprise
Allan Inman, a Manager-Entomologist with the Merced County Mosquito Abatement District, is looking for help from the public.
"This year it looks like it's shaping up to be a bad year," said Inman. "Typically when we have a wet spring that means it's going to be a bad mosquito year and it could be a bad year for mosquito borne disease, specifically West Nile Virus. We've had a very wet spring and I would estimate that just about everybody has some kind of a container or something around their house that's holding water. Those are potential breeding sites for mosquitoes."
The Merced County Mosquito Abatement District, along with similar agencies throughout California, is gearing up for a battle that will be fought during the next several months. To be effective, the mosquito abatement teams will be utilizing aircraft, specially outfitted pickups, and hopefully the direct involvement of citizens to mitigate the danger caused by the insects.
Mosquitoes can carry (or vector) numerous diseases including the potentially fatal West Nile Virus. Inman makes particular note of the fact that these pests also vector Western equine encephalitis, St. Louis encephalitis, and canine heartworm.
In speaking about the wet spring we have had, Inman suggests the possibility of a mosquito population explosion.
"What this does is it kind of produces a 'seed crop' and the population explodes based on the size of that seed crop," he said. Helping to thin the 'first wave' should help to curb the mosquito population later in the year.
Because three of the four life stages of mosquitoes are spent in standing water, members of the public can have a direct affect on the mosquito population around their homes and neighborhoods. By simply taking a few minutes to inspect their property for items capable of holding water and dealing with them citizens can significantly reduce potential breeding areas.
Residents are encouraged to look for obvious containers such as buckets, tires, seldom used bird baths, bottles, cans, clogged drainage systems, wheelbarrows, flowerpots, and children's toys including hollow climbers, and playhouses. Mosquitoes have been known to breed in items as small as a bottle cap. Almost anything that can collect water could be a potential breeding area and should be drained.
Inman also suggests checking a few not-so-obvious places.
"Something you might want to check are your gutters above the house. They might be stopped up and (mosquitoes) might be breeding up there," he said.
He also mentioned that the condensation from a swamp cooler or air conditioning unit, particularly those under a home, could also produce breeding areas.
Propagation of the West Nile Virus could become yet another consequence of the economic crisis that brought foreclosures by the thousands to this valley. Poorly maintained swimming pools on foreclosed properties are particularly troublesome.
"On a bigger scale what we need to look at is that a lot of houses have been foreclosed," said Inman who encourages the public to report swimming pools that are not being kept up properly. "Unfortunately the mosquitoes we are finding in swimming pools are Culex pipiens and Culex tarsalis the two primary vectors of West Nile Virus in Merced County which thrive in the swimming pools. Not only is it a nuisance but it's a public health threat.
"If you've got that bad swimming pool you can infect two or three blocks radius around you. You can be infecting your entire neighborhood."
The reporting of 'green pools' need not be limited only to abandoned homes.
"We can drive by and see what's in somebody's front yard but we don't know there's an abandoned swimming pool in the back, so we really rely on the citizens to call us and let us know," Inman said. "It can be completely anonymous."
In addition to reporting abandoned pools and ameliorating sources of standing water on their own property, Inman also wants the public to keep their eyes open for fresh avian carcasses, particularly crows, scrub-jays, and magpies which are extremely susceptible to West Nile Virus.
Inman asks that people who come across dead birds report them to the state's Dead Bird Program.
"If you see a dead bird that shows no signs of trauma, no obvious reason why the bird died, and it's within the first 24 hours, call the state," said Inman, who indicated that the bird may be picked up for testing.
Even if the bird is not picked up, Inman says it is still important to call it in because the state can work up a predictive model for the risk of West Nile transmission in humans based on the reports alone. The West Nile Virus and Dead Bird Hotline number is 1-877-968-2473.
Inman remains circumspect and is aware of the challenges that the district faces in the coming months.
"West Nile Virus is here to stay. We really need the public's help," he said. "Merced County is ground-zero for West Nile Virus. We've got more wetlands here than anyplace else. We've got over 300 dairies and 180 thousand plus acres of wetlands. We are the perfect storm right here in Merced County.
"2005 was our worst year, but last year we had our very first death from West Nile Virus in Merced County."
For more information on West Nile Virus, mosquitoes, and an online reporting tool for dead birds or squirrels go to The California Department of Public Health's website at: http://westnile.ca.gov/
