Now that the cold spring weather has broken and Memorial Day has passed, Minnesota's parks, lakes and campgrounds are abuzz with recreational activity. They are also abuzz with mosquitoes. Whether you live in the forests of the north or the plains of the south, these pests are ubiquitous in our state and can sometimes be shockingly abundant. The receding glaciers of the last ice age pocked the terrain and left the 10,000 lakes that provide our state's moniker. These pockmarks also result in widespread wetlands ideal for aquatic mosquito larvae. Of all the biting pests in Minnesota (and they are many), the mosquito is the most familiar to the extent that they even figure into an episode of the Paul Bunyan folklore. Although the bites of mosquitoes can range from annoying to maddening depending on the local mosquito density, the real health concern is from the transmission of mosquito-borne diseases. It was the absence of malaria that caused Dr. William Worall Mayo to move to Rochester and establish his medical clinic after he had recovered from multiple bouts of the disease back in Indiana. Although we were spared the worst of mosquito-borne diseases, mosquitoes in Minnesota have been known to transmit a variety of other pathogens. Since it arrived in the state in 2002, the most widespread mosquito-borne pathogen has been West Nile virus. In 2003, there were nearly 150 confirmed cases of West Nile fever. Since then, case numbers have declined with fewer than a dozen cases in several years. As recently as 2016, however, 83 cases were reported, indicating that West Nile virus will continue to be an issue in Minnesota. According to the Minnesota Department of Health, most people infected by West Nile virus don't get sick or only suffer from a relatively mild flu-like illness. About 20% develop West Nile fever characterized by high fever, headaches, back and joint pain, and rash. In the worst cases, 1 out of 150 people develop West Nile encephalitis. This is the life-threatening form of the disease. People with encephalitis are subject to confusion, vomiting, sensitivity to light and other neurological symptoms. West Nile encephalitis occurs most often in the elderly and has a death rate of 10%. There are several preventative measures that can be taken to reduce mosquito bites and the threat of disease. Wearing long sleeves and long pants will deter mosquitoes from biting exposed skin. Repellant chemicals approved by the EPA are highly effective at keeping mosquitoes away. The best known, most effective and longest lasting of these is DEET. Sprays containing up to 30% DEET are widely available and safe. If you are regularly visiting an area with a lot of mosquitoes, it may be worth purchasing a set of clothing treated with permethrin, a chemical that both repels mosquitoes (and ticks) and kills them on contact. Mosquito larvae thrive in human-created aquatic habitat. By cleaning up household debris that can hold pooled rainwater, we can reduce the amount of breeding habitat available. Car tires, birdbaths, buckets, pans and tarps can be covered, flipped, or stretched to eliminate puddled water. Take advantage of the long summer days while they last. But, bear a thought for what you can do to protect you and yours from Minnesota's favorite pest, the mosquito. Dr. Jonathan Oliver is an assistant professor at the University of Minnesota, Environmental Health Sciences.