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Zika Virus & Container Breeding Mosquito Control
in the United States . It is also capable of vectoring other viruses including dengue fever and Eastern equine encephalitis virus . The Asian tiger mosquito has adapted to survive in a broader temperature range and at cooler temperatures than the yellow fever mosquito . As a result , the Asian tiger mosquito can tolerate more temperate climates and has a broader distribution in the United States than the yellow fever mosquito ( Figure 2 ).
The yellow fever and Asian tiger mosquito live in close association with humans , largely due to their preferences in breeding sites . Both species seek out natural and artificial water-holding containers such as tree holes , bird baths , or plastic containers to lay their eggs . They can complete their lifecycle in as little as one half inch of water , making nearly any sized container a potential breeding site . After taking a blood meal , the female lays 100 – 200 black eggs ( 0.5 mm in length ) in small batches , across multiple sites . Each egg is glued to the inner wall of a container , just above the waterline . Following a rain event , the water level rises , submerging the eggs , triggering them to hatch . If the container dries out , the eggs can survive desiccation for eight months or more . Larval development is temperature dependent , but both species can reach adulthood in as little as seven days under ideal conditions .
MANAGEMENT
The basic approach to controlling container-breeding mosquitoes involves a three-step process : inspection and surveillance , source reduction , and chemical control . When executed properly , this integrated strategy can provide effective and continuous management of mosquitoes in a given area by eliminating breeding sites and reducing adult populations . The following information will provide direction on conducting this three-step process when managing yellow fever and Asian tiger mosquitoes . These two mosquito species are particularly well suited for local control on properties serviced by pest management professionals because of
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Both species seek out natural and artificial water-holding containers such as tree holes , bird baths , or plastic containers to lay their eggs .
the mosquitoes ’ propensity to breed in areas associated with humans and their limited dispersal range , rarely flying further than 100 meters from their larval development site .
The best indication that a site is producing mosquitoes is to confirm the presence of mosquito larvae .
Begin by identifying water-holding containers that could serve as potential breeding sites such as empty pots , children ’ s toys , bird baths , pets ’ water bowls and tree holes . Once found , containers can be visually inspected for larvae . If containers are hard to reach or too dark to inspect , a clear turkey baster can be used to siphon out water samples . Ovitraps are another effective surveillance tool that can be used to confirm the presence of mosquitoes in an area . Ovitraps are small water-holding containers designed to mimic the mosquito ’ s preferred breeding sites in order to attract egg-laying females . This type of trap can easily be constructed by placing a wooden tongue depressor in a small plastic jar or cup that is partially filled with water . A hole should be punched or drilled in the container to prevent the water level from rising too high . The tongue depressor should be inspected every few days for the presence of eggs . It is important to note that if ovitraps are left unattended they can become ideal breeding sites for mosquitoes , and therefore their locations should
be mapped and they should be removed if not inspected every few days .
Source reduction focuses on eliminating mosquito breeding sites . For these container breeding mosquitoes , primary breeding sites can include many items that are commonly found in residential backyards . If water is present in a container for more than seven days in a row , mosquitoes can complete development and the container has the potential to breed mosquitoes . Inspect the property frequently for items such as bottles , barrels , old tires , or other vessels that may hold water and remove them if possible . Tipping over any water containing items regularly that cannot be removed will prevent larvae from making it to adulthood .
Chemical control of container-breeding mosquitoes plays an important role in reducing both larval and adult populations in an area . Products intended to control the immature stages of mosquitoes are known as larvicides , while products used to control adults are known as adulticides . Larvicides such as methoprene or Bacillus thuringiensis israelensis ( Bti ) can be applied directly into water-holding containers . Methoprene , an insect growth regulator , does not kill mosquito larvae , but prevents them from developing into adults . Bti is bacterium that produces a toxin that is lethal to larvae upon ingestion . Adulticides can be applied using a gas-powered backpack mist blower to treat adult mosquito resting places such as shrubbery and other vegetation with an appropriately labeled residual insecticide . Mist blower applications allow for the deposition of insecticide onto the underside of leaves and interior architecture of shrubs more effectively than compressed air sprayers . Use caution to avoid treating plants that are in bloom and attractive to pollinators . Foundation walls and the undersides of decks may also be treated , as adult yellow fever and Asian tiger mosquitoes ( as well as others ), may rest there as well . Always carefully read and follow all label instructions .
PERSONAL PROTECTION
Managing mosquitoes requires pest management professionals to spend time in areas where mosquitoes are active , which can increase the risk of mosquito bites . While the risk of Zika virus and other viruses transmitted by these mosquitoes is low , to prevent mosquito bites in general , the U . S . Centers for Disease Control recommends applying EPA registered insect repellents containing the active ingredients DEET , picardin , oil of lemon eucalyptus ( OLE ), or IR3535 to exposed skin according to label instructions . When also using sunscreen , apply it before the repellent .
ADDITIONAL INFORMATION
For the latest information on the distribution of the yellow fever and Asian tiger mosquitoes in the United States , visit : http :// www . cdc . gov / chikungunya / resources / vector-control . html
• For more information on the health effects of Zika virus , visit : http :// www . cdc . gov / zika / symptoms / index . html
• For the latest information on the global spread of Zika virus , visit : http :// www . cdc . gov / zika / geo / index . html
• For more information on insect repellents , visit : http :// www . cdc . gov / westnile / faq / repellent . html