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Mosquito Information

How many kinds of mosquitoes are there?

There are about 3,500 different kinds of mosquitoes worldwide. About 36 of these mosquito species live in North Dakota.

What is the life cycle of a mosquito?

There are four distinct stages in the mosquito life cycle: egg, larva, pupa and adult. The first three stages are aquatic and last 5-14 days, depending on the species and the ambient temperature. Mosquito eggs are laid either near or on water. Eggs laid near water do not hatch until they are covered with water. Eggs laid on water start hatching soon after they are placed. Click here for more information on the mosquito life cycle.

What do mosquitoes feed on?

Only adult female mosquitoes feed on blood and transmit diseases, including West Nile virus. Female mosquitoes require a blood meal to provide necessary nutrition to produce eggs during their breeding season. They also may feed on nectar and other sources of moisture. Male mosquitoes are not blood feeders, rather they feed on nectar and other sources of moisture.

What types of mosquitoes are known to transmit West Nile virus?

West Nile virus has been detected in more than 30 kinds of mosquitoes. Only a few of these species are believed to be important in West Nile virus transmission. Of the 36 mosquito species in North Dakota, 12 are known carriers of West Nile virus. The most important vector in North Dakota is the Culex tarsalis.

How do mosquitoes transmit West Nile virus?

West Nile virus occurs mostly in birds. Mosquitoes pick up the virus when they feed on infected birds and transmit it when they feed on uninfected birds. When the number of infected birds and mosquitoes reaches a certain level then transmission to other animals, including humans and horses, occurs.

West Nile virus does not build up in sufficient amounts in the blood of humans or horses to be acquired by a mosquito for subsequent transmission. The virus occurs in much higher concentrations in the blood of certain birds, which is why they are so important in the transmission cycle.

What does the North Dakota Department of Health do for mosquito surveillance?

There are approximately 50 sites throughout North Dakota that are designated as mosquito trapping sites. New Jersey mosquito traps are located in 41 counties. The New Jersey mosquito traps are collected each week and sent to the North Dakota Department of Health's Division of Laboratory Services where the number of mosquitoes is calculated. The numbers of female Culex, Aedes, Anopheles, and other species trapped in each area of the state are recorded. Click here to view weekly mosquito counts. CDC light traps are located in nine counties throughout the state for live trapping of mosquitoes. The mosquitoes are sent to the Division of Laboratory Services weekly and tested for West Nile virus, Western equine encephalitis virus, Eastern equine encephalitis virus, La Crosse virus, Jamestown Canyon virus, Saint Louis encephalitis virus, and Zika virus.

What can be done to prevent mosquito bites and/or control mosquitoes?

  • Use insect repellents registered with the U.S. Environmental Protection Agency (EPA) that contain ingredients such as DEET, picaridin, IR3535, oil of lemon eucalyptus (or PMD), or permetherin. Always follow the directions on the manufacturer's label for safe and effective use.
  • Wear light colored, loose fitting clothing. Studies have shown that some species of mosquitoes are more attracted to dark clothing and most can readily bite through tight-fitting clothing. When practical, wear long-sleeved shirts, long pants, and socks.
  • Limit outdoor activities between dusk and dawn when mosquitoes are most likely to bite.
  • Eliminate areas where mosquitoes may lay eggs by draining any standing water around your house.
    • Dispose of any tires.
    • Clear roof gutters of debris.
    • Check and empty children's toys.
    • Change the water in bird baths at least once a week.
    • Canoes and other boats should be turned over or covered.
    • Empty water collected in tarps around the yard or on woodpiles.
    • Even the smallest of containers that can collect water can breed many mosquitoes. Examples include bottles, flower pots, buckets, overturned garbage can lids, etc. Do not let these items lay around the yard. Mosquitoes do not need much water to lay their eggs.
  • For information on mosquito control in the United States, please read this joint statement from the EPA and CDC.
  • For information on Integrated Pest Management (IPM), please visit the National Park Service's IPM Manual website.