Jamestown Vector Control Department
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Jamestown Vector Control Department
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COMMONLY FOUND SPECIES OF MOSQUITOS The Genus Aedes
The genus Aedes, contains more than 500 species distributed from the polar regions to the tropics. Almost one-half of all North American mosquitoes belong to this genus, which includes many of the major pest species as well as important disease vectors. There are some 70 species of Aedes known from the United States of which about 40 may be rather common, at least in certain regions. In general the Aedes mosquitoes assume greater importance as one goes from the tropics northward. In the northern United States, as well as in Canada and Alaska, many species of Aedes occur and are often present in astronomical numbers. All species of Aedes lay their eggs either singly on the ground or at, or above, the waterline in tree holes or containers. These eggs hatch after flooding and in some species they are able to survive long periods of drying. Many of the northern species have only one brood a year. Their eggs do not hatch until they have been subjected to periods of drying and cold. Other species are intermittent breeders and have several generations per year depending on rainfall or irrigation practices. All Aedes species occurring in regions with cold winters pass the winter in the egg stage. Breeding places for larvae of Aedes are extremely variable. In general, they breed in temporary pools formed by rains or melting snow. Some species breed in coastal salt marshes that are flooded at intervals by unusually high tides. Others have become adapted to irrigation practices. A few species breed in tree holes, rock pools, and artificial containers. Practically all species of Aedes are blood sucking in habit. Many species are vicious biters of great economic importance. Their biting habits are variable, but they most frequently attack during evening hours. Some species, however, bite only during the day, and others bite either by day or by night.
The Genus Anopheles Anopheline mosquitoes are distributed throughout the United States. One or more species is present in every state except Hawaii. Most Anophelines have spotted wings while most culicines have no wing spots. Female anophelines have the palpi about as long as the probiscis, whereas female culcines have the palpi much shorter than the probiscis. Anophelines rest with the head, thorax, and abdomen all in a straight line, held at an angle of 40 to 90° to the surface on which they are sitting. Culicenes usually rest with the thorax and abdomen somewhat parallel to the surface on which they are sitting. The eggs of anophelines are always laid singly on the water surface. They have lateral floats to keep them at the surface. The female lays her eggs in batches of 100 or more. Each female can lay several such batches in her lifetime--a total of 400 to 500 eggs or more. The eggs hatch in two to six days. Breeding is continuous during the warm seasons of the year. Anopheline larvae are found in many different types of water, but mainly in permanent bodies of fresh water. Two species, A. atropos and A. bradleyi breed in salt or brackish waters. All other anophelines in this country breed in fresh water. The larval stage lasts from 6 to 7 days to several weeks, depending upon the species and environmental conditions, especially water temperature. The larvae feed just beneath the water surface where they ingest microscopic animal and plant life. Most anophelines breed in water that contains aquatic plants. Anopheline larvae are often abundant where aquatic plants provide protection from fish and other predators. Most adult anophelines are active at night. They spend the daytime hours resting in dark, damp shelters. They are most active just after dark and again just before daylight. The flight range varies from less than one mile to several miles. Most anophelines need a blood meal before they can lay fertile eggs. The species in the United States feed more frequently on the blood of domestic animals than on man. The winter is usually passed as hibernating, fertilized females. A. walkeri overwinters in the egg stage.
The genus Culex The genus Culex includes about 300 species most of which occur in the tropical and subtropical regions of the world. Some 29 species have been reported in the United States although only 12 of these are at all common. The group includes several important pest species and disease vectors. Culex mosquitoes breed in quiet waters of almost all types from that in artificial containers to large bodies of permanent water. Water in which there is considerable organic material including sewage is often a favored breeding place. The eggs are deposited in rafts of 100 or more. They remain afloat on the water surface until hatching occurs some 2 or 3 days later. Breeding continues throughout the warm season with several generations a year in the Southern States. The adult females are generally inactive during the day, biting at night.
Aedes Dorsalis Aedes flavescens
Aedes nigromaculis Aedes trivittatus
Culiseta inornata Mansonia perturbans
Aedes vexans Anopheles punctipennis
Culex pipiens Culex restuans
Culex tarsalis
*Written material found above is quoted from MOSQUITOES OF PUBLIC HEALTH IMPORTANCE AND THEIR CONTROL, provided by the Dept. of Health, Education, and Welfare in Public Health Service's Center for Disease Control. *Illustrations provided by the Vector Control Program of Cass County. back to home |
