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WINTER MARSH
MOSQUITO
GENERAL INFORMATION
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The
Winter Marsh Mosquito (Culiseta
inornata) is one of 53 types of mosquitoes that occur in
California. One of California's largest mosquitoes, it reaches a size of
10 mm or almost 1/2". Adults are a light brown or reddish-brown in
color with no unusual or distinctive markings. Populations of this
mosquito have been found in most California counties. Total
developmental time from egg to adult varies from two to seven weeks
depending on water temperature and weather conditions.
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Daily Activity:
Adults are present fall, winter and spring entering
diapause (a form of hibernation) in the summer as a means of surviving
California's dry weather. Aestivating females are thought to emerge
from mammalian burrows and shelters in the fall following decreased
temperatures and the first fall rains. Both males and females are
strongly attracted to lights. The average life expectancy for adult
females varies from 90 to 145 days depending on temperature, humidity and
availability of nutrients. Adults usually do not swarm and females
freshly emerged from their pupal case are mated by waiting males.
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Flight Range:
Adults of San Francisco Bay area populations tend to stay
close to their breeding sites, usually traveling less than two miles for a
blood meal. The maximum recorded flight range is 14 miles.
Optimal flight activity occurs on overcast, cool days and an hour before to
an hour after dark.
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Feeding:
Adult female mosquitoes feed primarily on large domestic
mammals although San Francisco Bay area populations associated with brackish
marshes have been significantly pestiferous to humans.
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Eggs and Larvae:
Clusters of glued together eggs, also known as egg rafts, are laid directly
on the water with a typical egg raft containing 150-200 eggs. Studies
have shown that the eggs of this mosquito can tolerate temperatures as low
as 17 degrees Fahrenheit, with 50% of the eggs surviving after a 48 hour exposure.
Larval emergence usually occurs within two to three days. Total larval
developmental time varies from one to six weeks depending on temperature,
weather conditions, competition for space and available nutrients.
Larvae are tolerant of moderate organic pollution and have been found
developing in water with a salinity of 26 ppt (72% that of seawater). |
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DISEASES TRANSMITTED
Winter Marsh Mosquitoes do occasionally create domestic, industrial and
agricultural pest problems when they are present in large numbers. No
known mosquito-borne diseases have been linked to this mosquito
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WINTER MARSH
MOSQUITO LIFE
CYCLE |
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Winter Marsh Mosquitoes have four life stages: egg,
larva, pupa, and adult. The immature stages need standing water to
complete their life cycle.
After an adult female lays her eggs they hatch into
larvae (wrigglers), which feed on small organic particles and microorganisms
in the water. Feeding occurs when they hang from the water's surface by
the tip of their tail (siphon) or by browsing along the bottom of their
habitat. Because they are air breathing organisms they must return to
the water's surface to breathe. About one to six weeks 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. Under optimum
conditions, development from egg to adult takes about two weeks.
However, all mosquito developmental times are dependent on the temperature
and nutrients of the water in which they mature.
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CONTROL METHODS |
| Where possible, the best approach is to prevent mosquitoes from
breeding by modifying their breeding sites. Careful planning
and coordinated efforts with landowners, regulatory agencies and
concerned citizens is essential for any wetlands restoration or
enhancement project. |
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RESIDENTS SHOULD |
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If you have a mosquito problem call your
local Mosquito Abatement District to identify the problem. That
is the first step in identifying what type of mosquito is being
dealt with. |
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Use insect repellents if it is necessary
when in an area where this mosquito is found. Read and follow
the directions carefully! |
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PERSONAL PROTECTION FROM MOSQUITOES |
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FIRST AID FOR MOSQUITO BITES |
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Reduce
outdoor activities during peak feeding periods. |
q
Wash
bite with soap and water. |
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q
Wear
long pants and long sleeved shirts. |
q
Apply
anti-itch medication. |
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q
Apply
insect repellent. |
q
Apply
cold cloth for swelling. |
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q
Watch
for secondary infections. |
For more information on
Winter Marsh
Mosquitoes contact:
Napa County Mosquito Abatement District
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