Warmer weather’s onset in Nebraska marks the arrival of the deadliest animal, the mosquito, which is responsible for malaria, dengue fever, and the West Nile virus. There are 50 species of mosquitoes in Nebraska, and they are both a nuisance pest and a health pest, with half of them feeding on human blood. Only females bite because they require blood to produce eggs. Both male and female mosquitoes obtain nutrients from plant nectar.
In Nebraska, mosquitoes are often equated with the West Nile virus, which is prevalent, manifesting itself with no symptoms at times to flu-like symptoms and fever, severe neurological damage, and death.
Mosquitoes transmit diseases by injecting saliva and anticoagulants with their piercing mouth parts to aid in attaining a blood meal from the host. Pathogens are acquired from infected hosts, replicating in the mosquito’s body and are then transmitted to others, all without harming the mosquito. This can be person to person, bird to bird, or in the case of West Nile virus, bird to human.
Mosquito bites become itchy as that is the body’s response to the mosquito’s saliva. The human immune system releases histamines that cause the itching, swelling and redness at the bite site. It is important to refrain from scratching, in order to avoid secondary bacterial infections. Everyone reacts differently, and sometimes, the use of over-the-counter anti-itch treatments may help to relieve discomfort.
Because mosquitoes are aquatic in the egg, larval and pupal stages, it is important to dispose of any stagnant water. Mosquitoes will breed in the smallest amount of water, so dumping water out of containers, dog bowls, planters, saucers, tires, children’s pools and toys will remove potential breeding sites. Get rid of standing water at least once a week to break up the mosquito life cycle.
When water cannot be dumped, special solutions can be dissolved in troughs, fishponds, rain barrels, and birdbaths. These products contain the active ingredient bacterium Bacillus thurengiensis israelensis (Bti), which is toxic to mosquito larvae when consumed, but is non-toxic to humans, pets, pollinators, fish, and other wildlife. They are effective immediately and last for up to one month.
Fix and repair window and door screens to keep mosquitoes out of the house. Other preventative measures include avoiding the outdoors during peak mosquito times, such as dawn and dusk. Wear light-colored, loose-fitting clothing because mosquitoes prefer dark colors and can bite through fabric. Use effective insect repellents.
Mosquitoes are attracted to the carbon dioxide we expel. Insect repellents that contain DEET change the receptors of mosquitoes, which prevent the insect from detecting humans. The pests may still land, but they will not bite if coverage is thorough and applied properly. DEET repellents with a 25-30% concentration are effective at deterring mosquitoes for eight hours. Higher percentages allow for longer protection, but it is suggested to only apply to the skin the percentage that is needed. High percentages of DEET (98%) will dissolve plastics, so apply with care when using around watches, cameras, sunglasses, and other plastic objects.
Caution is needed when spraying aerosols near eyes and faces. Creams and liquids may provide better application coverage. Use lower percentages on children; do not apply to children’s hands and reapply as necessary. If also applying sunscreen, apply the sunscreen first, then the insect repellent. Apply to skin, but not to skin covered by clothing.
Another method that helps repel mosquitos involves using battery-operated devices outdoors. Some devices use a butane cartridge that heats a chemically treated repellent mat. The device keeps mosquitoes out of the area for a number of hours and relies on allethrin as the active ingredient. Consumer reviews suggest that such devices are effective, especially for prolonged outdoor use. Users should be aware that allethrin is an insecticide and should be used according to directions.
Finally, permethrin sprays (which are pesticides) are sold specifically to treat clothing. These sprays can remain effective through multiple wears and four to six washes. Follow the instructions and allow all clothing to dry before wearing. Some clothing lines are factory-pretreated with permethrin, which remains effective against mosquitoes and ticks for up to 70 washes.
At present, no single product or device is available to homeowners that is both economical and effective. Some professional companies use fogging, misting, and blowing equipment, which apply insecticides to places where adult mosquitoes rest, but they may contain a lethal dose of insecticide. Professionals should make applications to non-flowering vegetation, tree canopies, bushes, underside of leaves, sidewalks, decks, crawlspaces, under decks and other cool, dark locations. Chemical treatments alone only offer temporary relief and are best combined with other preventive measures.