small, long-legged
insect of the order Diptera, the true flies . The females of most species
have piercing and sucking mouth parts and apparently they must feed
at least once upon mammalian blood before their eggs can develop properly.
The males may have beaks, or probosces, but cannot pierce, and they
feed upon fruit and plant juices. The female produces the characteristic
whining sound by vibrating thin horny membranes on the thorax. The eggs
are laid singly or glued together to form rafts, usually in stagnant
water in ponds, pools, open containers, and other aquatic habitats-the
particular type of habitat depending on the species. The aquatic larvae,
or wrigglers, pass through four larval stages, feeding on microscopic
animal and plant life. Except in the genus Anopheles, the wriggler has
an air tube near the end of the abdomen and makes frequent trips to
the surface to use it as a supplement to the gills. The pupa, or tumbler,
shaped like a question mark, takes no food but surfaces often to breathe
through air tubes on its thorax. In summer the life cycle may take only
two weeks, resulting in several generations a year in some species.
Mosquitoes have become adapted to extremes of climate and are found
far north of the Arctic Circle, where they winter as larvae frozen in
the ice. Dragonflies, damselflies, and several insectivorous birds are
the natural enemies of the adults; the wrigglers are eaten in large
quantities by small fishes and aquatic insects. Mosquitoes are classified
in the phylum Arthropoda , class Insecta, order Diptera, family Culicidae
DAMAGE AND CONCERN
During the blood
meals the females may either acquire or transmit various disease organisms.
Many species of Anopheles mosquitoes, recognizable by their tilted resting
position, carry the protozoan parasites that cause malaria ; species
of the genus Aedes transmit the viruses responsible for yellow fever,
jungle yellow fever, and dengue fever ; and in the S United States and
in the tropics, members of the genus Culex, to which the common house
mosquito belongs, are vectors of filariasis, the infection by a filarial
worm that causes elephantiasis , and human encephalitis .
CONTROL
One method of
mosquito control is the spreading of oily substances on infested water,
which prevents access to air and suffocates the pupae.
Control of these major insect pests by other than natural means poses
many problems; the long-range harmful effects of many insecticides are
very serious, and swamp drainage tends to upset the balance of nature
in addition to eliminating the mosquito.
Bibliography:
See bulletins of the U.S. Dept. of Agriculture; study by A. Spielman
and M. D'Antonio (2001).
Columbia Encyclopedia,
Sixth Edition, Copyright (c) 2003.

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Pest Control, Inc.