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Mosquitoes: A Rogue's Gallery
Family Culicidae
Mosquitoes are vector agents that carry disease-causing viruses,
bacteria, and parasites from person to person without catching
the disease themselves.
Here are different species of live adult mosquitoes
photographed at various locations as noted.
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Asian Tiger Mosquito,
Aedes albopictus Vero
Beach, Florida
Photos by Sean McCann used with
permission |
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Ochlerotatus infirmatus
Mosquitoes have four distinct life stages, with the
first three stages of Culiseta (egg-larva-pupa) being spent
in the water. An adult female lays about 150-200 eggs in
clusters called rafts, which float on the surface of the
water until they hatch in about two days. The eggs hatch
into larvae (wigglers), which then feed on small organic
particles and microorganisms in the water. About 10 days are
required for larval development. At the end of the larval
stage, the mosquito molts and becomes the aquatic pupa
(tumbler). The pupa is active only if disturbed, for this is
the "resting" stage where the larval form is transformed
into the adult. This takes about two days during which time
feeding does not occur. When the transformation is
completed, the new adult splits the pupal skin and emerges.
Larvae are found in a wide variety of standing water sources
including creeks, fish ponds, abandoned swimming pools,
stagnant and polluted waters, log ponds, reservoirs, snow
pools, brackish water, horse troughs, artificial containers,
and even discarded automobile tires. Under optimum
conditions development from egg to adult takes about two to
three weeks. However, all mosquito developmental times are
dependent on the temperature and food values of the water in
which they develop.
Females feed primarily on fowl and domestic animals but on
occasion will bite humans. Due to the limited flight range
of this mosquito, most breeding sites are located near the
area of complaints. Males do not bite, but feed on nectar
and plant juices. Culiseta incidens is primarily a
domestic nuisance and in some regions is considered
relatively unimportant as a human pest. Successful
laboratory experimental transmission of St. Louis
Encephalitis (SLE), Western Equine Encephalitis (WEE) and
Japanese B Encephalitis (JBE) virus does indicate a
potential medical importance for this mosquito.
Where breeding sites exist in standing or slow moving water,
corrective action to permanently eliminate them by such
means as filling, pumping, ditching or draining is
recommended. Ornamental ponds and watering troughs are
common sources. Often the cool weather mosquito may be
controlled in a source by stocking mosquito fish (Gambusia
affinis).
Due to the often delicate environmental interrelationships
of some ponds, chemical control should only be practiced by
trained mosquito abatement or health department personnel.
These officials have knowledge of the proper compounds and
application techniques to assure minimal environmental side
effects. Public health agencies generally are able to
provide information and assistance where organized mosquito
control programs are unavailable. It is important to
remember that chemical control provides only temporary
relief and is used by public agencies until other measures
can be implemented. Commonly available insect repellents may
be useful if it is necessary to be in an area where large
numbers of this species exist. --excerpts from
Marin / Sonoma Mosquito & Vector Control District |
Aedes taeniorhynchus
A mosquito's proboscis consists
of six parts: two pairs of sharp,
flexible serrated blades and
sharp-tipped knives, used to cut the
hole in skin into which the whole
apparatus is inserted, and two very
fine tubes; one for injecting an
anticoagulant into the wound, and
the other for sucking blood into the
mosquito's body. You can see an
excellent electron micrograph of the
proboscis tip
HERE.
Mosquitoes
are a vector agent that carries
disease-causing viruses and
parasites from person to person
without catching the disease
themselves. Female mosquitoes
suck blood from people and other
animals as part of their eating
and reproductive habits. The
female mosquito that bites an
infected person and then bites
an uninfected person might leave
traces of virus or parasite from
the infected person's blood. The
infected blood is injected
through, or on, the "dirty"
proboscis into the uninfected
person's blood and the disease
is thus spread from person to
person. When a mosquito bites,
she also injects saliva and
anti-coagulants into the blood
which may also contain
disease-causing viruses or other
parasites. This cycle can be
interrupted by killing the
mosquitoes (actually, it's more
efficient to kill their larvae
before they become airborne),
isolating infected people from
all mosquitoes while they are
infectious or vaccinating the
exposed population. All three
techniques have been used, often
in combination, to control
mosquito transmitted diseases.
Window screens, introduced in
the 1880s, were called "the most
humane contribution the 19th
century made to the preservation
of sanity and good temper."
Mosquitoes are estimated to
transmit disease to more than 70
million people annually in
Africa, South America, Central
America, Mexico and much of Asia
with millions of resulting
deaths. In Europe, Russia,
Greenland, Canada, the United
States, Australia, New Zealand,
Japan and other temperate and
developed countries, mosquito
bites are now mostly an
irritating nuisance; but still
cause some deaths each year.
Historically, before mosquito
transmitted diseases were
brought under control, they
caused tens of thousands of
deaths in these countries and
hundreds of thousands of
infections.[16] Mosquitoes were
shown to be the method by which
yellow fever and malaria were
transmitted from person to
person by Walter Reed, William
C. Gorgas and associates in the
U.S. Army Medical Corps first in
Cuba and then around the Panama
Canal in the early 1900s. Since
then other diseases have been
shown to be transmitted the same
way.
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Cool Weather Mosquito, Culisseta incidens
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Mosquitos have killed more humans than
all other insects combined
In much of the world, mosquitoes are a
major public health problem; they are estimated to transmit
disease to more than 69 million people annually. In the
United States, Australia, New Zealand, the UK, Scandinavia,
and other temperate countries, mosquito bites are mostly
just a nuisance. However, global warming is increasing the
range of mosquitos worldwide, resulting in increased
frequency of dengue fever, Ross River fever, malaria and
other mosquito borne diseases.
The mosquito genus Anopheles carries the malaria parasite,
Plasmodium. Worldwide, malaria is a leading cause of
premature mortality, particularly in children under the age
of five, with around 5.3 million deaths annually, according
to Center for Disease Control. Most species of mosquito can
carry the filariasis worm, a parasite that causes a
disfiguring condition (often referred to as elephantiasis)
characterized by a great swelling of several parts of the
body; worldwide, around 40 million people are living with a
filariasis disability. Most species of mosquito can carry
the viral diseases yellow fever, dengue fever, epidemic
polyarthritis, Rift Valley fever, Ross River Fever, and West
Nile virus. Mosquitoes do not transmit HIV. Viruses carried
by arthropods such as mosquitoes or ticks are known
collectively as arboviruses. West Nile virus was
accidentally introduced into the United States in 1999 and
by 2003 had spread to almost every state.
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Aedes cinerus - Burnaby, British Columbia, Canada
Yup, the little bastard bit him:
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