Cathleen Allison/Nevada Appeal
With nearly two straight weeks of spring rain, Carson City's mosquito "Swat Team" had to move in on their targets earlier than ever this year, officials said.
"Teresa started in April looking around, but depending on how much water we get, we could be done by July," said Dustin Booth, supervisor for the city's Division of Environmental Health.
Teresa Hayes, lead environmental health specialist during mosquito season, works for months to keep one step ahead of mosquito colonies in the capital city.
"We have water every year in certain areas, but with two weeks of rain, it filled up all our storm drains," Hayes said. "We're seeing a lot more activity in those areas. The first two weeks of June, we got a flood of calls about mosquitoes."
Hayes tiptoed over rocks and poked among reeds and grasses of the Linear Ditch near Governor's Field Tuesday morning, submerging her dipping cup into the shallow water to scoop out a sample.
"Here's one," she called out, touching a larva near the top of the water in the cup. It quickly dove to the bottom.
"He's angry," she said, pointing out that mosquito larvae are brown and furry worm-like creatures.
Once they enter the pupa stage, they turn black and look like commas before emerging as adult mosquitoes, she said.
"There isn't much here," Booth said as he watched. "We've come across areas where there were so many that the water was just black or you could actually see the water moving."
Carson City uses an insect growth regulator to treat areas where mosquitoes breed. The black sand-like granules dissolve in water and are specific to mosquitoes. They work by shutting down the hormones so that if the adult does emerge, it doesn't have wings or legs and it quickly becomes bird food, Hayes said.
"There are so many species that depend on them for lunch," she said.
Helicopter treatments are used in some of the city's large areas every 3-4 weeks. Those include the Anderson Ranch, the Silver Saddle Ranch, along the Carson River corridor and at the Empire Ranch Golf Course, Booth said.
Other areas are so small, Hayes treats them by hand as needed.
"Most of town is spot specific," she said.
And no mosquito season is ever the same, Hayes said, adding, "Every year I learn something new."
A new challenge this year was the seepage that occurred along the embankments of the Mexican Ditch at Riverview Park.
Moles excavating holes in the embankments to escape high water, along with the steady downpours this spring, caused the banks to become saturated and muddy.
"They were growing mosquitoes there like there was no tomorrow," Hayes said. "It just started to dry out yesterday."
Booth suggests that next time you swat that mosquito on your arm, you might want to take a closer look at what is making a meal out of you.
There are two types of mosquito in this area and they each possess their own endearing qualities.
The flood water types, from the aedes genus, are far more aggressive and they don't need a water surface to breed - they can lay their eggs in the mud. Nor do they believe in waiting until dusk or dawn to dine. They can bite at any time of the day, Hayes said.
The permanent types, from the culex genus, while known for being more discriminate eaters, are the ones most likely to carry disease such as the West Nile virus, equine encephalitis and St. Louis encephalitis, Booth said.
"There have been no reports of West Nile virus so far this year in this area, but Clark County had its first report recently," he said.
Another distinction amongst mosquitoes is between male and female.
Females are the only ones that bite because they need the blood to lay their eggs. They live long lives, sometimes over the winter and can fly as far as 18 miles. Males, on the other hand, live only about 45 days. They breed with the female, but otherwise go about their business pollinating miniscule flowers that birds and bees can't get to.
"They are very misunderstood," Hayes said.
Booth said the best prevention is a product that contains DEET.
"DEET is still the proven best, but in concentration it can remove paint," he said, laughing.