Bzzz. Bzzz.

What's that?

A mosquito in your ear.

Don't fear. This time of year, it's more of a pest.

The North Dakota Department of Health division of disease control began its mosquito monitoring for West Nile virus. The virus affects horses, birds and humans.

The health department started setting out traps over Memorial Day, and data will be tracked on the West Nile virus Web site this week.

"Numbers are low," health department microbiologist Mike Trythall said. "That's to be expected."

The mosquitoes being caught are species that are not disease carriers like the one that carries West Nile. There are about 100 different species of mosquitoes in North Dakota, and most are "nuisance mosquitoes," Trythall said. This means they bite but don't transmit diseases.

The species that has people taking precautions against West Nile is culex tarsalis. This mosquito tends to emerge when the weather gets hot, about mid- to late July and August, Trythall said.

The severity of mosquito season depends on the temperature and moisture. Cool, dry environments are less hospitable to mosquitoes than an environment with hot weather and standing water.

When disease-transmitting mosquitoes are out, people could be bit by one without any problems. About 80 percent of the time, people have West Nile without showing symptoms, according to a fact sheet from the department of health. For people who do show symptoms, they will have a fever, headache and nausea, which will last a few days. More severe symptoms, such as tremors, disorientation and muscle weakness, can occur. West Nile can be fatal.

In North Dakota last year, there were no deaths and 86 reported cases of West Nile in humans.

The state tracks the occurrrance of West Nile through mosquito counts and other approaches.

The state is doing its mosquito count with 102 traps set in the state. The traps are in cities, state parks and in each county, Trythall said.

The traps are 21/2 feet high cylinders, with a light bulb to attract the bugs, a fan to suck them into the cylinder, and a jar at the bottom of the cylinder with insect repellent to collect the bugs. Jar contents are put into collection bags once a week, and the mosquitoes are sorted from the other bugs in the lab.

Beside checking mosquitoes, the health department is checking sick horses and birds as part of its surveillance for West Nile. The birds included in the surveillance are crows, magpies, blue jays and ravens. Dead birds can be reported to the department of health through the Web site at www.ndwnv.com. In addition to contacting the department of health, people can contact the local public health department, an extension agent, North Dakota Game and Fish, the U.S. Fish and Wildlife Service and the USDA Wildlife Services. The virus is not spread by touching dead birds.

The easiest way for people to prevent West Nile is to not get bitten by a mosquito. This includes using insect repellent with DEET, removing stagnant water and keeping grass trimmed around the house.

"Install screens on windows and doors, and empty buckets and flower pots," health department epidemiologist Erin Fox said.

She also said she recommends people stay indoors when mosquitoes are at their height of activity - at dawn and dusk.

The precautions for mosquitoes also will help people from getting bitten by another of summer's blood-sucking insects: the tick.

With warmer weather comes tick season. The dog tick and deer tick are found in North Dakota, with the dog tick being the most common. It's about an eighth of an inch, and it likes to get its little head under some skin.

The best way to remove a tick is with tweezers, and pull from as close to the head as possible, she said.

Ticks are mostly seen in wooded areas and tall grasses. If people keep lawns mowed and trees trimmed back from their homes, they shouldn't have a problem with ticks around the house, she said.

"You might still see them, and they can be brought in with pets," she said.

Wearing light-colored clothing, long sleeves, insect repellent with DEET and tucking pant legs into socks can help deter the tick.

The ticks can spread tularemia, Rocky Mountain Spotted Fever and lyme disease. The number of cases in North Dakota are few. Since 2000, there have been two cases of Rocky Mountain Spotted Fever, four of lyme disease and two of tularemia, Fox said.

(Reach reporter Sara Kincaid at 250-8251 or sara.kincaid@;bismarcktribune.com.)