Mosquitoes - Coachella Valley Mosquito and Vector Control District

potential blood meal that contrast with their background.
use control products to kill adult mosquitoes, but only
The ability is enhanced when the potential host is mov-
when populations become so large as to cause extreme
ing.
annoyance or when the threat of an outbreak of disease-
Heat sensors - Mosquitoes can detect heat from warm
blooded animals from short distances.
causing pathogen is high.
Public Outreach And Detection
Programs
Mosquito Control
The Coachella Valley Mosquito and Vector Control District’s objectives are to keep mosquito populations below
levels where they become a nuisance or serious public
health problem, leading to an outbreak of disease.
fish farms, duck clubs, school districts, and homeowner
quito season.
•
Wear long pants and long sleeved shirts when outside.
•
Use approved mosquito repellent such as DEET, Pidirections.
water, where mosquitoes tend to
sources and prevents new ones so that Coachella Valley
residents and visitors may enjoy full use of their backyards and recreational facilities. Mosquito abatement
control
Avoid outside activity at dawn and dusk during mos-
ter management to prevent accumulation of standing
In partnership with the University
Vector
•
caridin or Oil of Lemon Eucalyptus and follow label
ods, the District minimizes existing mosquito breeding
and personal comfort.
How to Protect Yourself and Family
associations to promote proper soil, vegetation and wa-
breed.
industrial working conditions, and protect public health
Stock ornamental ponds with mosquito fish and remove excess vegetation.
The District works with date, citrus and row crop growers,
Applying the latest integrated vector management meth-
measures also promote mosquito free agricultural and
•
First Aid for Mosquito Bites
•
Wash bite area with soap and water
of California and the California
•
Apply anti-itch medication
Department of Public Health Ser-
•
Apply cold cloth for swelling
•
Guard against secondary infections
vices, on-going early disease detection and warning programs encompass routine adult
What you
should know
about
Mosquitoes
mosquito sampling for virus detection, and bi-weekly serological blood samples from sentinel chicken flocks to
test for viral activity.
technicians
search for mosquito breed-
Who Should You Contact
When encephalitis virus activity is detected, the District
ing habitats and use ap-
intensifies control measures to reduce both the adult and
propriate control measures
larval mosquito populations to prevent transmission of
that are cost-effective and
environmentally friendly. Control measures include reducing aquatic habitats, applying mosquito-specific control agents, and stocking mosquitofish that feed on the
larvae. Many materials are biological in origin, highly
the virus to humans, domestic animals and livestock.
How Can You Help Control
Mosquitoes
Coachella Valley Mosquito and
Vector Control District
43-420 Trader Place
Indio, CA 92201
(760) 342-8287 or (888) 343-9399
Eliminate Backyard Mosquito
specific for mosquitoe larvae and minimal effect on other
organisms.
Breeding Sources
Controlling irrigation water
in agricultural areas to avoid
excess runoff is an important
mosquito
control
method.
Occasionally, the District may
•
Filter, clean and chlorinate swimming pools and
spas regularly.
•
Empty all containers that may hold water, including
bird baths, weekly.
Coachella Valley Mosquito and Vector Control District
43-420 Trader Place
Indio, CA 92201
(760) 342-8287 * (888) 343-9399
www.cvmvcd.org
Introduction
The oldest known mosquito with a modern anatomy was
found in 79-million-year-old Canadian amber from the
Cretaceous. An older sister species with more primitive
features was found in amber that is 90 to 100 million
nia the most important consequence of mosquito blood
Larvae also called wigglers, hatch
peaks: In March/April and in late September/October.
feeding is the potential transmission of micro organisms
from the eggs in stagnant or nearly
Culex tarsalis prefers to feed on birds, but readily attacks
that cause disease in humans such as western equine
still water found in surface pools,
humans, horses, and cattle.
encephalomyelitis (WEE), St. Louis encephalitis, (SLE)
tree holes, and man-made contain-
and West Nile virus (WNv).
ers. Culex and Aedes larvae have
years old. There are approximately 3,500 species with
These viruses can cause serious, sometimes fatal neu-
the majority belonging to 3 major genera: Aedes (eggs
rological ailments in people. WNv infections can range
are laid on moist soil land that will receive water at cer-
from no detectable symptoms to severe neuro-invasive
tain point), Anopheles and Culex (eggs are laid in quiet,
diseases. WNv and WEE can also affect horses, oc-
standing water).
casionally other livestock and domestic animals. Even
Mosquito is Spanish for “little fly.” Adult mosquitoes are
small, delicate, two-winged flies that have, small scales
covering their long, slender wings and long legs.
Female mosquitoes have a slender proboscis, a tubular feeding organ adapted for piercing skin and sucking
ed swimming pools. Birds are its principal blood meal
source; however they will attack humans and invade
and do not feed. Adult mosquitoes
cephalitis virus (eg., SLE, WEE, and WNv) in California,
quito bites can result in secondary infections, allergic re-
emerge from the pupae stage in 2
but its role in the natural transmission of these viruses is
actions, pain, irritation, redness, and itching.
to 3 days; male mosquitoes usually
considered to be secondary to that of Culex tarsalis in
emerge first.
rural situations. However, in urban environments, Culex
Western encephalitis mosquito
Culex tarsalis
Accidental Dead End Hosts;
Humans and Animals
ranging from deserts to mountain meadows of 10,000
Resevoir Host
Birds
While many species seldom pose a threat to humans,
Adult mosquitoes mate soon after
quinquefasciatus may be the primary WNv vector.
emergence; females will then seek
Psorophora columbiae, breeds in irrigated fields, pas-
a blood meal. Females require the
tures, flooded date gardens, and citrus groves. A female
extra nutrition to mature the large
lays about 100 eggs scattered on moist soil, particularly
number of eggs they will lay during each egg laying cycle.
where there is growth of grass. In mid-summer Ps. co-
On average the female usually deposits from 100 to 150
lumbiae can develop from an egg to an adult in just four
eggs at a time. Over the life course the female mosquito
days. A fierce day and night biter, the female feeds pri-
may deposit 3 to 4 batches of eggs.
marily on cattle and horses, but dogs, pigs, rabbits and
humans may also be bitten. In California, Psorophora
several species readily attack people and animals and
can transmit pathogens that cause human diseases such
Valley, are the western encephalitis mosquito (Culex tar-
become pupae
tanks, catch basins, waste treatment ponds, and neglect-
can be a serious nuisance and health problem as mos-
More than 50 species occur in California with habitats
Mosquitoes of public health concern, in the Coachella
larger after each molt. The fourth instar of larvae molt to
waters, typically in artificial containers, fish ponds, septic
homes. This mosquito has been found infected with en-
only for sucking plant juices and other sources of sugar.
Nile virus and others.
organic materials in the water, molt three times, growing
to the Salton Sea. Larvae breed in foul or highly polluted
Pupae, or tumblers, are aquatic,
to produce eggs. Male mosquitoes use their proboscises
as encephalitis, malaria, yellow fever, dengue fever, West
lacking in Anopheles. Larvae feed on microorganisms and
a nuisance to residential communities from Palm Springs
when mosquitoes don’t transmit infectious diseases, they
blood. The female mosquito needs the protein in blood
feet or more.
a siphon or air tube at the rear of their bodies, which is
The southern house mosquito, Culex quinquefasciatus, is
Southern house mosquito
Culex quinquefasciatus
Life Cycle
Problem Species And Their Habitats
in the Coachella Valley
Habitats in the Coachella Valley suitable for breeding
mosquitoes range from marshes around the Salton Sea,
columbiae is not a vector of human diseases, only is a
major pest species.
How Can Mosquitoes Find You?
Mosquitoes have a battery of sensors to track their prey.
In the summer, the life cycle from egg to adult can be
agricultural areas in the east valley to bird baths, ponds,
completed in less than a week, depending on water tem-
neglected pools, hot tubs or any artificial containers in
Chemical sensors - Mosquitoes can
perature and the species of mosquito.
backyards.
sense carbon dioxide and volatile
Eggs deposited on water surfaces
The western encephalitis mosquito, Culex tarsalis, is the
usually hatch within a day or so,
most important indigenous species in the valley and the
while those deposited in soil can
primary vector of the St. Louis encephalitis (SLE), west-
Female mosquitoes require blood from vertebrates such
hatch months or even years later
ern equine encephalomyelitis (WEE) and West Nile virus
as people, pets, livestock, and birds. Currently in Califor-
depending on water availability.
(WNv). This mosquito breeds year round with two distinct
salis), southern house mosquito (Culex quinquefasciatus)
and flood irrigation mosquito (Psorophora columbiae).
Public Health and Veterinary
Importance
compounds up to 100 feet. Mammals and birds give off these gases
as part of their normal breathing. Certain chemicals in
sweat also attract mosquitoes.
Visual sensors - Mosquitoes can see and orient towards