|Medical Services ●Disease Control|
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 and 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. However, only a very few species are expected 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. West Nile 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?
In North Dakota there are appoximately 100 sites statewide that are designated as mosquito trapping sites with New Jersey mosquito traps covering all 53 counties (click here to see the map of the sites). The New Jersey mosquito traps are collected every week and sent to the North Dakota Department of Health's Division of Laboratory Services where the number of mosquitoes is counted. The numbers of total mosquitoes are determined, as well as the number of female Culex, Aedes and Anopheles and other species trapped in each area of the state. Click here to view weekly mosquito counts.
What can be done to prevent mosquitoes?
Copyright � 2007 North Dakota Department of Health