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Are invasive Aedes mosquitoes in my neighborhood? 

Invasive Aedes mosquitoes have now been identified in all of the cities within the District's boundaries

Are Repellents Safe? 

DEET is the most widely available and tested repellent. Products containing DEET are very safe when used according to the directions. Because DEET is so widely used, a great deal of testing has been done. To read more information about DEET safety see the National Pesticide Information Center (NPIC).

DEET (N,N-diethyl-m-toluamide) (

Are there different kinds of mosquitoes? 

Yes! There are 53 species in California and we regularly trap 13 in the Coachella Valley. However, the three species of greatest public health concern in the valley are the Culex tarsalisCulex quinquefasciatus and the Aedes aegypti. These species are capable of transmitting disease to people.

Are there precautions I should take if spraying will occur in my area? 

Although mosquito control pesticides and the techniques pose low risk to people, to ensure the maximum impact of the operation the District recommends that residents stay inside during and for 30 minutes following the application. The product should have no adverse effects on people, pets, birds, mammals, or fish, when applied according the label instructions.

Can adulticides harm insects or wildlife? 

The products we use are targeted to control flying adult mosquitoes. Adult mosquitoes are most active at night whereas beneficial insects - such as bees - are active during the day. That is why when applying adulticides, we treat at night. The products are applied at very low dosages that kill a flying mosquito on contact, then degrades. When the product is exposed to sunlight, the ingredients become inactive. 

The US Environmental Protection Agency (EPA) has evaluated pesticides for their safety and has determined that they do not pose an unreasonable risk to birds or mammals, if used according to the product label directions.

Residents may choose to stay indoors during and for 30 minutes following the application as a best practice to reduce exposure. After going back outside, residents should not see any visual signs of the treatment on their property.

Can mosquitoes transmit coronavirus (COVID-19)? 

No. According to the World Health Organization, there is no evidence to suggest this new virus can be transmitted by mosquitoes. COVID-19 is a respuratory virus which spreads primarily through droplets generated when an infected person shares saliva or discharge from the nose, such as coughs or sneezes. Mosquitoes transmit differents diseases - such as West Nile virus (WNV).

Mosquitoes become infected when they feed on infected birds, which circulate the virus in their blood for a few days. The virus eventually gets into the mosquito's salivary glands. During later blood meals (when mosquitoes bite), the virus may be injected into humans and animals, where it can multiply and possibly cause illness. 

Do bats serve as an effective mosquito control? 

Bats in temperate areas of the world are almost exclusively insectivorous. Food items identified in their diet are primarily beetles, wasps, and moths. Mosquitoes have comprised less than 1% of gut contents of wild-caught bats in all studies to date.

During the 1920's several bat towers were constructed near San Antonio, Texas, in order to help control malarial mosquitoes. Mosquito populations were not affected and the project was discontinued.

Bats tend to be opportunistic feeders. They do not appear to specialize in particular types of insects but will feed on whatever food source presents itself.

There is no question that bats eat mosquitoes, but to utilize them as the sole measure of control would be folly indeed, particularly considering the capacity of both mosquitoes and bats to transmit diseases. 

Do birds show symptoms of West Nile virus? 

Research indicates birds have somewhat similar symptoms to people. Studies done with crows indicate that when crows are infected they have difficulty with balance and are lethargic sleepy, problems with the nervous system.

The University of Minnesota

Does the district remove bee hives from private properties? 

No. Hives or swarms found on residential property are the responsibility of the homeowner. If a bee hive is found in or on a private structure, we encourage residents to contact a licensed bee keeper or private pest control company licensed for bee removal. Private pest control operators licensed by the State can be found at

The District may carry out bee removal in cases where hives or swarms are located in a non-structural and accessible location, such as trees and bushes, in a public place where the bees pose an imminent threat to the public.

If I am a beekeeper, should I take special precautions to protect the bees before or after aerial spraying? 

We do not anticipate negative impacts on honey bee colonies since the aerial spraying takes place at night. If bees are congregating outside the hive box(es), consider applying a cover to the hive entrance or over the entire hive box(es) using a loose wet cloth (burlap, sheet, etc.) to prevent bees from exiting, thus not allowing for direct contact during the application. Remove covers and additional boxes placed on hives as soon as possible the morning following application.

The products used breaks down rapidly in sunlight. Similar Districts monitor honey bee hives during similar applications and has not witnessed any negative effects on honey bees from the use of these products.

How do I know if that ant is RIFA? 

RIFA can be only distinguished from other southern ants by professionals using magnifying equipment. Adult RIFA are reddish to dark brown and range from 1/8 to 1/2 inches long.Fire ant mounds vary in size but are usually in direct proportion to the size of the colony. For example, a mound that is 2 feet in diameter and 18 inches high may contain 100,000 workers, several hundred winged adults and one queen.One of the identifying characteristics of a RIFA colony is the earthen nest or mound, with a hard rain-resistant crust.RIFA respond rapidly and aggressively to any disturbance of the colony. A single fire ant can sting repeatedly and will continue to do so even after their venom sac has been depleted. Initially, the stings result in a localized intense burning sensation followed by the formation of a white pustule at the sting site within 24 - 48 hours.Fire ants prefer oily and greasy foods and forage for sweets, proteins, and fats. They also feed on many other insects, as well as earthworms and carrion. Workers forage around their mound often in underground tunnels that radiate from the mound.

How do I request a free presentation or tour? 

The District is eager to provide information on mosquito and other vector threats to the Coachella Valley. We can go to you or you can come to us. Take advantage of our free educational opportunities:

  • Presentations! City Council, community, or school presentations about vectors, their biology and habitats, and diseases they transmit.
  • Educational booths! Live mosquito life cycle displays, information materials, free repellent, fly swatters, and other useful, mosquito-combatting stuff.
  • Interactive programs! Tailored for classrooms, events, Girl and Boy Scout troops, camps, community centers, and neighborhood associations, includes a presentation, a life-sized backyard display, mosquito-eating fish, and other age-appropriate activities. 
  • Job shadows! Spend a day or a morning each week learning how we use science to best achieve our mission of reducing vectors to protect public health.
  • Internships! We work with Health Career Connections to provide a college student a paid summer internship to practice what they are learning in university.
  • District tours! See firsthand the District's state of the art laboratory, mosquito fish ponds, and operations, information technology, fleet services, and public outreach departments. 

Contact Tammy Gordon at (760) 342-8287 or submit a request via email to schedule a presentation, invite us to set up a booth, or schedule a tour.


    How do mosquito control districts control mosquitoes? 
    • Integrated mosquito management methods currently employed by organized control districts are endorsed by the CDC and EPA.  They employ comprehensive and specifically tailored control methods for each stage of the mosquito life cycle.  Larval control through water management and source reduction is a prudent pest management practice, as is the use of the environmentally friendly EPA approved larvicides.  When source elimination and larval control measures are unattainable or in the case of imminent disease, the EPA and CDC have emphasized in a published joint statement the need for considered application of adulticides.  A successful mosquito management program includes the following elements:
    • Larval and adult mosquito sampling (surveillance and trapping)
    • Source reduction
    • Larviciding and adulticiding when indicated by surveillance
    • Resistance monitoring
    • Disease surveillance in mosquitoes
    •  And public education
    How do mosquitoes get into my house? 

    Mosquitoes can get into any space through any tiny portal available; broken windows, screens, bathroom vents and garages.

    How does a mosquito find an animal or human to bite? 

    Female mosquitoes are attracted to the gas (carbon dioxide) that humans and other animals breathe out. Mosquitoes can follow a stream of carbon dioxide from as far as 50 feet away. Mosquitoes are also attracted to substances like lactic acid on your skin, which your body produces in greater amounts when exercising. Mosquitoes may also be attracted to certain scents or fragrances and are more attracted to dark colors than light colors.

    How far and high do mosquitoes fly? 

    Depends on the species. Native Culex mosquito species can fly as far away as a mile. The invasive mosquito's habitat is in urban areas and they prefer to stay close to their food source so they only fly a few hundred feet from where they emerged from their egg.

    In general, mosquitoes that bite humans prefer to fly at heights of less than 25 feet.

    How is aerial spraying conducted? 

    Ultra-low volume (ULV) adult mosquito treatments by helicopter are applied in areas with strong virus activity that has been detected multiple times.

    The District’s Mosquito-Borne Virus Surveillance and Emergency Response Plan helps target control applications where risk of WNV transmission is greatest. Despite control efforts, surveillance in some areas may indicate unidentified sources of standing water maintaining ideal breeding conditions for mosquitoes.

    Larval mosquito control targets immature mosquitoes in the water using a naturally occurring bacterium to kill mosquito larvae before they can develop into biting adults. The product is environmentally friendly, approved for application on organic crops, and has no effect on people or pets at the amounts used for mosquito control. It is registered with the U.S. Environmental Protection Agency and the California Department of Pesticide Regulation.

    Adult control is only a small part of our overall program but a critical component to reduce disease transmission and protect the public from mosquito-borne disease. Ultra-low volume (ULV) treatments are carried out when the adult population of mosquitoes or infected mosquitoes passes a threshold and poses a risk to people.

    How long do I have to wait for another mosquito treatment? 

    Time lapses between services rely heavily on the product used. In general, we can reapply barriers after 30 days.

    How long do mosquitoes live? 

    Most female mosquitoes live for less than 2 weeks and most male mosquitoes live for less than a week. However, when the conditions are right, some mosquitoes will live up to 8 weeks. The life cycle of all mosquitoes includes four different stages: egg, larva, pupa, and adult. It takes about a week for the mosquito to go from and egg to a biting adult.

    How long should a person or pet wait before going into an area recently treated? 

    For liquid applications, no person or pet should be in the vicinity during the application. The District recommends you wait about 30 minutes before entering a sprayed area to give the product time to dry.

    For a granular treatment, such as a product targeting RIFA, the District recommends avoiding the area while ants are harvesting the bait to avoid being bitten.

    How much do your services cost? 

    There are no charges for inspections or services. The District is funded by property taxes and is a Special District separate from cities and counties. Services are your tax dollars at work.

    Traveling overseas? 

    Avoid bringing mosquito-borne viruses home!
    If chikungunya, dengue, or Zika is present in a country you will be visiting, you and your family are at risk of getting sick from mosquito bites when you visit. Follow these steps to prevent mosquito bites and prevent potentially starting local transmission of these viruses in the Coachella Valley:

    • Cover exposed skin by wearing long-sleeved shirts and long pants.
    • Use insect repellents that are registered with the Environmental Protection Agency (EPA) and contain DEET, IR3535, picaridin, oil of lemon eucalyptus (OLE) or para-menthane-diol, or 2-undecanone (methyl nonyl ketone). Always use as directed.
    • Pregnant and breastfeeding women can use all EPA-registered insect repellents, including DEET, according to the product label.
    • Most repellents, including DEET, can be used on children older than 2 months of age. To apply, adults should spray insect repellent onto hands and then apply to a child’s face.
    • If it might be difficult to find recommended repellent at your destination. Pack enough to last the entire trip.
    • Use permethrin-treated clothing and gear (boots, pants, socks, tents). You can buy pre-treated items or treat them yourself.
    • Stay and sleep in screened-in and air-conditioned rooms whenever possible or sleep under a mosquito bed net if air conditioned or screened rooms are not available or if sleeping outdoors.
    • Mosquito netting can be used to cover babies younger than 2 months old in carriers, strollers, or cribs to protect them from mosquito bites.
    There are different percentages of DEET available for sale out there, which one do you recommend? 

    The Center for Disease Control (CDC) recommends 30%

    What can be done to reduce risk of viruses in the Coachella Valley? 

    The best line of defense is to protect yourself from being bitten (e.g., using repellents, ensuring window and door screens have no holes, and wearing clothing that covers your skin while outdoors).

    Removing standing water (e.g., removing potential breeding sites, such as garbage cans, flower pots, bird baths, discarded auto-tires or other containers that hold water) is most useful for decreasing virus risk.

    If there is a high risk of human disease, control activities may take place. That may include reducing populations of mosquitoes while they are still in their immature (larval) state and reducing populations of adult, flying mosquitoes using truck-based ground spraying.  

    What can I do to avoid being bitten? 

    If possible, avoid scheduling outdoor activities during dawn and dusk.  Wear light, loose fitting clothing. Wear mosquito repellent.

    What do I need to know about repellents? 

    Use Environmental Protection Agency (EPA)-registered insect repellents with one of these active ingredients:

    • DEET
    • Picaridin 
    • IR3535
    • Oil of lemon eucalyptus (OLE)

    When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women. Find the right insect repellent for you by using the EPA’s search tool.

    What does a field Technician do? 

    State certified Technicians survey an assigned portion of the valley for mosquito breeding in various sources like, neglected pools, drains, street gutters, channels, neglected fountains, or anything else holding water when it comes to controlling mosquitos in the field. We also work on eliminating red imported fire ants (RIFA) from parks, residences, and other areas where they are present.

    What do I do if I find a dead bird? 

    When a bird dies, there is a short window to test for WNV. The virus immediately starts to break down after death which makes birds that are dead for more than 24 hours not good candidates for testing.

    To report a dead bird, you can call the hotline – 1-877-WNV-BIRD (1-877-968-2473) or and click Report a Dead Bird. The hotline is staffed by people who can answer questions about West Nile and about other mosquito-borne diseases.

    What does it mean to be a virus? 

    Viruses are distinct from all other biological entities on Earth because they lack one key feature of all living organisms: the ability to reproduce on their own.Like living cells, viruses are comprised of genetic material protected by proteins, and sometimes membranes, but their genomes are vastly smaller than their bacterial counterparts — up to 100s of times smaller! With limited genomic capacity, a virus cannot reproduce on its own. Instead, viruses require a host cell to supply the building materials and machinery needed to make more viruses while the virus provides the genetic blueprint.Because viruses are completely dependent on their hosts to replicate, they have evolved a vast arsenal of tricks for getting into host cells, co-opting those cells to make more viruses, and then escaping to infect more cells. Viruses have developed these tricks through millions of years of evolutionary battle with their hosts — the host evolves to avoid the virus and the virus evolves countermeasures to evade host defenses and gain access to its cellular machinery. After so much back and forth, most host-virus interactions are very species specific and indeed, many viruses only infect specific kinds of cells within their hosts. Each virus has evolved a life cycle strategy to overcome its inability to reproduce on its own, and that strategy affects when and where disease outbreaks occur.After figuring out how to invade and replicate in host cells, viruses also have to get from host to host. Some viruses are spread via biting (rabies), sex (HIV), sneezing or coughing (influenza), or fecal contamination of drinking water (polio). WNV uses mosquitoes to carry it from bird to bird, birds being the hosts that it uses for amplification within the environment.

    What does it mean to find a positive mosquito samples? 

    The District regularly traps and tests mosquitoes throughout the Coachella Valley.

    There are two types of mosquitoes in our valley that can be found with - and transmit - viruses such as West Nile Virus (WNV), Saint Louis Encephalitis Virus (SLEV), and Western equine encephalitis (WEE). When virus is found in mammal-biting mosquitoes, the risk for human disease increases because these mosquitoes are much more likely to bite people. Wet, warm weather make optimal conditions for abundant mosquito breeding and a high risk of occurrence of human cases.

    What does the CV Mosquito and Vector Control District do? 

    The District’s mission is to protect the public health by using scientifically-driven integrated vector management techniques (IVM). IVM is a rational decision-making process which seeks to improve the efficacy, cost-effectiveness, ecological soundness and sustainability of disease-vector control. The ultimate goal is to prevent the transmission of vector-borne diseases.

    The District is staffed with highly experienced staff to help you with vector services. To find out what happens when a service is requested, check out this video.

    What if I think that I am experiencing an adverse reaction to pesticide spraying? 

    If you believe you may be experiencing any health effects from pesticides, call your health care provider. If symptoms are severe, call 911 for assistance. 

    What is a safe age I can start using mosquito repellent on my baby? 

    Always read the label before applying any repellent.

    • Do not use insect repellent on babies younger than 2 months old.
    • Instead, dress your child in clothing that covers arms and legs.
    • Cover strollers and baby carriers with mosquito netting.
    • Do not use products containing oil of lemon eucalyptus (OLE) or para-menthane-diol (PMD) on children under 3 years old.
    • Do not apply insect repellent to a child’s hands, eyes, mouth, cuts, or irritated skin. Spray insect repellent onto your hands and then apply to a child’s face.
    What is a vector? 

    A vector is “Any animal capable of transmitting the causative agent of human disease or capable of producing human discomfort or injury, including but not limited to: mosquitoes, flies, mites, ticks, other arthropods, and rodents and other vertebrates”. (California Health and Safety Code Section 2002(k)).The District’s objectives are to keep vector populations below levels where they become a serious public health problem, leading to an outbreak of disease.By monitoring environmental conditions that can increase risks for vector-borne disease, the Coachella Valley Mosquito and Vector Control District can help protect the overall health of the public.

    What species of birds can be tested? 

    American Crows and California Scrub-jays have a high mortality rate once infected. However, all species of birds may be tested except chickens, doves, pigeons, and quail. These species are not tested because they are not known to die of WNV.

    To report a dead bird, please call the WNV and dead bird call center (toll free number: 1-877-968-2473; 1-877-WNV-BIRD) at the Vector-Borne Disease Section, California Department of Public Health (CDPH). Open five days a week during the WNV season (approximately mid-April to mid-October). Hours are 8 am t 4:30 pm, M-F, with Sundays added during peak season. The public can also report dead birds online:

    When are spraying insecticides considered? 

    Our mission is to protect the community from mosquito-borne diseases. When mosquito populations increase, the risk of local transmission is higher. Control applications are assessed based on the "Mosquito-Borne Virus Surveillance and Emergency Response Plan." This ensures that we treat when there is increased disease risk but not when the risk is low.

    Truck-mounted ultra-low volume (ULV) mosquito control applications involve emitting a fine mist to target flying adult mosquitoes.

    Aerial control is an important tool for mosquito control. It helps reduce mosquito populations in areas that are hard to reach and allows us to knock down new generations of the mosquito quickly to prevent additional spikes in the mosquito population.

    All control products used by the District are registered by the Environmental Protection Agency for the purpose of controlling mosquitoes and protecting public health. The products are applied according to label instructions by trained and certified technicians.

    When Should I Use Mosquito Repellent? 

    Apply repellents when you are going to be outdoors and will be at risk for being bitten by mosquitoes, especially around dawn and dusk when mosquitoes are most active. If you're outside during these hours pay special attention to using repellent. The safest decision is to use repellent whenever you are outdoors, even if it is only for a few minutes.

    When treating a property, are the products you use safe? 

    Pesticides when used according to the label are safe. The majority of our pesticides we use are a category 3 class of pesticide with the signal word “Caution”. The toxicity of this category of pesticides is equivalent to that in common house hold cleaning items which has the signal word “Caution”.

    District Technicians are State certified and trained to handle pesticides in a safe manner following label directions to target a specific pest.

    Where are mosquitoes usually found? 

    Most adults spend the day in damp, shady areas where they can find protection from the sun; some of them will even hide in your house. Mosquitoes need water to lay their eggs in and plants to hide in so they are usually found around water and plants. Mosquito eggs are laid on water or damp soil where the young mosquitoes grow and develop.Different mosquitoes prefer different kinds of water. Some like swamps or ponds and others prefer water in swimming and wading pools, old tires, watering cans, flower pots, trash cans, etc. When the young mosquito turns into an adult, it leaves the water and flies away.

    Which mosquitoes transmit West Nile Virus? 

    Culex species is usually the primary vector.

    Which repellent works best? 

    N,N-diethyl-3-methylbenzamide (DEET) remains the standard and most effective.  There are a variety of mosquito repellents on the market both chemical and natural.  There is some experimentation to find which works the best for your body.  Also, rotating between several types helps.  Follow the manufacturer’s directions.  Product with Picaridin, and Oil of lemon-eucalyptus are also very effective.

    Why are mosquitoes attracted to me? 

    Carbon dioxide is the most universally recognized mosquito attractant and draws mosquitoes from up to 50 feet away.  As we breathe, we exhale Carbon dioxide.  Other cues include body odors, such as sweat, lactic acid, perfumes, and body movement.  

    Why dead birds? 

    Birds play a central role in the WNV transmission cycle. If an infected mosquito feeds on a bird and transmits WNV, the infected bird can then serve as a reservoir of WNV to other mosquitoes. Many bird species are susceptible to WNV and die as a result of infection; for example, American Crows and California Scrub-jays have a high mortality rate once infected. A positive dead bird is often the first indication that WNV is present in an area.

    To report a dead bird, please call the WNV and dead bird call center (toll free number: 1-877-968-2473; 1-877-WNV-BIRD) at the Vector-Borne Disease Section, California Department of Public Health (CDPH). Open five days a week during the WNV season (approximately mid-April to mid-October). Hours are 8 am t 4:30 pm, M-F, with Sundays added during peak season. The public can also report dead birds online:


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