Mosquitoes are the most important insect pests that affect the health and well-being of humans and domestic animals worldwide. They can cause a variety of health problems due to their ability to transfer (vector) viruses and other disease-causing pathogens, even in the arid Southwest U.S.
Mosquito-vectored diseases of humans include: arboviral encephalitis (brain inflammation), Dengue fever, Chikungunya, Zika, Yellow Fever, Malaria and Filariasis. Mosquitoes are not known to transmit blood-borne pathogens such as hepatitis or HIV. Different mosquitoes vector specific diseases, and many mosquito species are not vectors of any human disease.
The most susceptible to the effects of these mosquitoborne pathogens are children and the elderly. However, in some instances life-threatening illness and/or permanent debilitation can occur in infected human hosts of any age.
Understanding the basics of mosquito biology will help you manage mosquitoes and related disease risks. All mosquitoes must have water to complete their life cycle, although some species require very little water and can develop in a thin moisture film. The mosquito life cycle is an example of complete metamorphosis. There are four distinct stages in the life of a mosquito: egg, larva (aquatic feeders), pupa (aquatic non-feeders) and adult (Fig. 1). Like most insects with complete metamorphosis, mosquitoes have developmental stages that look very different from one another.
1. Eliminate standing water in plant pots, birdbaths, fountains, tires, tarpaulins covering boats or other objects, and backyard trampolines and other items. Check for standing water after every rain or at least once per week, twice per week is ideal.
2. Remove unnecessary clutter. Keep rain gutters free of leaves and other debris that prevent water from draining. Store boats, canoes and other objects so they do not collect rainwater. Saucers placed under potted plants are a favorite breeding site for Aedes aegypti. They should be drained after watering or removed entirely. If eggs are suspected, they need to be scrubbed away, otherwise they remain viable for months, and will hatch later.
3. Repair water leaks (leaky pipes, sprinkler systems, and outside faucets). Correct drainage problems in yards and playing fields. Report drainage problems in ditches, etc.
4. Empty water containers for pets regularly and check livestock watering troughs and tanks. Mosquito eating fish can be added to large (undrainable) water troughs for livestock and horses.
5. Cover rain-collection barrels with insect exclusion netting.
6. Merchant (2016) offers tips on eliminating tree-hole breeding sites:
▪ Do not fill tree holes with concrete, gravel or sand. Gravel and sand may hold water in the tree and promote decay. Gravel and concrete pose a real safety hazard for arborists or tree owners if the tree eventually must be cut down.
▪Drilling drain holes to keep water from accumulating is no longer recommended, as it may open the tree up to infection.
▪ Not all tree cavities need to be filled. However, if a tree hole is retaining water, expanding foam may be a good solution. Use a foam with a lower expansion ratio and inject the foam slowly to protect the tree. It is not necessary to clean out decay from the cavity before filling with polyurethane foam (e.g., Great Stuff ProTM Gaps & Cracks Foam, Foam & Fill® Expanding Poly Sealant, or similar product).
For more information view our Biology and Integrated Mosquito Management Publication Here
Avoid Mosquito Bites
When outdoors, consider the following safety tips:
1. Wear light colored clothing with loose fitting long-sleeves, long pants and socks. Use protective clothing when exposure to mosquitoes cannot be avoided.
2. Properly apply insect repellent even if you are outside for just a short period of time, and share your insect repellent with those around you. For additional help selecting which repellent is right for you, go to the EPA search page: http://cfpub.epa.gov/oppref/insect/#searchform.
3. Use a DEET-containing product or a good non-DEET alternative http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4667684/pdf/iev125.pdf and, if you are outside for more than a few hours, reapply repellent frequently.