Mosquitoes
Mosquitoes are insects that
belong to the order Diptera, the True Flies. Mosquitoes
differ from other flies in that mosquito wings have scales. Female
mosquitoes' mouthparts form a long antennae (proboscis) for piercing and
sucking. Males differ from females by having feathery antennae and
mouthparts not suitable for piercing skin. Blood-feeding females usually
must ingest a blood meal in order to develop eggs. Saliva injected by females
while engorging on blood causes itching. Males, as well
as females, sip nectar, honeydew and fruit juices. There are over 2500
different species of mosquitoes throughout the world; about 200 species
occur in the United States with about 55 species of mosquitoes occurring
in Texas and 77 species in Florida.
The Name "Mosquito"
"Mosquito" is a Spanish
word meaning "little fly". The Spanish originally called
mosquitoes "musketas," and native Hispanic Americans
called them "zancudos" meaning "long-legged". The two
words apparently combined to form "mosquito" in Spanish
North America and dates back to the late 1500's.
What is the correct plural form of the word mosquito?
In Spanish it would be "mosquitos," but in English
"mosquitoes" (with the "e") is correct.
Mosquitoes can be an annoying pest or a very serious
problem. They interfere with work and spoil hours of
leisure time. Their attacks on farm animals can cause
sickness and decreased production. We best know
mosquitoes for their role in the transmission of
diseases, such as malaria, yellow fever, dengue fever,
encephalitis and West Nile virus. Of these, malaria is
by far the most important. According to recent data
released by the World Health Organization and the
Centers for Disease Control, mosquitoes infect a minimum
of 500 MILLION people with the disease each year, and
more than two million -- mostly children in sub-Saharan
Africa -- die of it.
The mosquito goes through
four separate and distinct stages of its life cycle:
Egg, Larva, Pupa, and Adult. Each stage is easily
recognized by its special appearance. The egg, larva and
pupa stages depend on temperature and species
characteristics to determine how long they take for
development.
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Egg: |
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Eggs are laid one at a time
or more commonly attached together to form
"rafts" where they float on the surface of
the water. The more commonly known Culex
species, lays its eggs together in rafts of
up to 200 eggs or more. Other species lay
their eggs singly. Some lay their eggs on
the surface of the water while others lay
their eggs on damp soil later to be flooded
by water. Most eggs hatch into larvae within
48 hours. Water is necessary to their
habitat. |
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Larva: |
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Once hatched, the larva
(plural - larvae) lives in the water and
comes to the surface to breathe. Most larvae
hang upside down from the surface of the
water and use siphon tubes for breathing
while some attach to plants for oxygen.
Larvae shed their skins, referred to as
molting, four times during this stage and
grow larger after each molt. Larvae depend
on microorganisms and organic matter in the
water for a food sources. It is during the
fourth molt that the larva transforms into a
pupa. Larvae live in water from 4 to 14 days
depending on water temperature. |
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Pupa: |
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The pupal stage is a resting,
non-feeding developmental stage. During this
stage, pupae are mobile and respond to
changes in light. They move by flipping or
wagging their tails to move towards
protected areas. This is the stage in which
the mosquito changes into an adult. This
process is similar to a caterpillar
developing into an adult butterfly while in
the cocoon. This takes about two days for
the Culex species. The adult mosquito
emerges after development is complete. Pupae
may live in water 1 to 10 days depending on
species and water temperature. |
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Adult: |
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The newly emerged adult rests
on the surface of the water for a short time
to allow itself to dry and all its body
parts to harden. It cannot fly unless its
wings are spread and dried properly. Blood
feeding and mating will not occur until a
couple of days after it has emerged. Mating
usually occurs near the emergence site, and
the male dies shortly after. |
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Only female mosquitoes
require a blood meal (protein) and bite
animals - warm or cold blooded - and birds.
Male mosquitoes do not bite, but feed on the
nectar of flowers or other sources of liquid
carbohydrates. Both male and female
mosquitoes are primarily nectar feeders.
Horses, cattle, smaller mammals and/or birds
are the preferred blood sources for those
female mosquitoes that are capable of blood
feeding; humans are secondary. Some adult
mosquitoes may live a few weeks or longer. |
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