Mosquito season returns

82 percent rise in Healdsburg service calls
With the ongoing California drought and dry summer heat, water is a welcome respite for many. However, standing water also brings in mosquitoes, and there are many more emerging now than there were last summer.
As a result of the current climate, service request calls to the Vector Control District have skyrocketed. Service calls from Healdsburg have risen an alarming 82 percent.
“We’ve had an influx, the sheer number of calls we’ve been getting for tree hole mosquitoes has been astounding,” said Nizza Sequeira, public relations director for the Marin-Sonoma Mosquito and Vector Control District (MSMVCD). “We’re coming out of a drought, and so what has happened is a lot of areas that hadn’t been holding water in the past are now holding water, or even areas that generally don’t hold water are holding water… With warmer temperatures, mosquitoes go through their life cycle faster.”
Tree hole mosquitoes are one of the more aggressive and common types of mosquitoes in the area, and as their name says, they lay eggs in rotten holes of oak or bay trees. They emerge in the springtime, after the rot holes are filled with water. Another notable type is the salt marsh mosquito, though those are mainly reported in Marin.
Mosquitoes are more than just annoying pests. Besides the painful bites and itching, they are vectors, which means they can transmit diseases or parasites from one animal to another. Some can carry canine heartworm, which can be fatal to both dogs and cats. Others may transmit viruses that are dangerous or possibly deadly to humans, such as Zika virus or the West Nile virus.
“Our lab sets out trap lines in specific areas to monitor virus activity and abundance of mosquito in specific areas,” Sequeira said. “Trap lines are traps that are set in the same place every year. We have three trap lines in the vicinity of the Sebastopol-Santa Rosa border near the Laguna. The abundance of mosquitoes captured in those traps lines has increased 146 percent from 2015 year-to-date … The species of mosquitoes caught in those traps vary but do include vectors of West Nile virus and canine heartworm.”
The only California reports of the Zika virus are from those who got it while traveling outside of the country, or had sexual contact with an infected man who traveled outside of the country. According to the California Department of Public Health, the main vectors that carry it are the Aedes aegypti and Aedes albopictus mosquitoes. These mosquito types are not native to California, but have been detected in several California counties since 2011, the closest ones being Alameda and San Mateo counties.
Though just one case of the Zika virus has been reported in Sonoma County (a man who contracted it in Central America), just last week, MSMVCD sent out a press release reporting California’s first 2016 instance of the West Nile virus after a dead crow tested positive in San Rafael. For West Nile virus, the most common transmission is through mosquitoes, though there is a very small chance to get it through blood transfusions, organ transplants, exposure in a lab setting or from mother to baby.
The CDC reports that 70 to 80 percent of infected individuals have no symptoms. About one in five develop a fever along with body aches, headache, vomiting, diarrhea, joint pains or rash. Less than one percent of infected people develop a neurological illness like encephalitis or meningitis. Symptoms for these conditions include neck stiffness, high fever, paralysis, headache, seizures, disorientation, tremors or coma. Recovery may take several weeks or month, while some effects may be permanent. In rare cases, 10 percent of those one percent who develop a neurologic infection will die.
The MSMVCD had to downsize their staff due to budget cuts, meaning they’ve lost four employees. “Four positions – those duties have been absorbed by our technicians, who have had to take on an additional workload,” Sequeira said. This has led to a slowed response time for sending technicians out to mosquito-infested areas.
There are several ways to combat mosquitoes in your own backyard. The first thing is to tip over any pockets of standing water around the home, including water trapped on tarps, containers such as cans or barrels that may still have liquid inside, make sure that lids to rainwater catch basins or septic systems are tightly sealed and that vent pipes have screens installed.
Another method is to pick up free mosquitofish for a house pond or other permanent water feature from the MSMVCD office. Each day, mosquitofish may consume up to three times more than their body weight in mosquito larvae. Pick up at their office at 595 Helman Lane in Cotati Monday through Friday 7 – 11:30 a.m. or 12:30 – 3:30 p.m. Alternatively, request a free delivery online through 1-800-231-3236 or place a request online at www.msmosquito.com. They also have an online “Mosquito School” section for kids, including work sheets and coloring pages to study mosquitoes and their habits.
To protect yourself, you can wear long-sleeved shirts and long pants, as well as use a mosquito repellent. The MSMVCD suggests one with an active ingredient of oil of lemon eucalyptus, Picaridin, DEET or IR3535.
Finally, report mosquito problems or neglected swimming pools or spas where mosquitoes could spawn so they can be dealt with before it becomes a larger issue.