Mosquitoes are one of the most important insect pests
that affect the health and well being of humans and domestic
animals worldwide. If environmental conditions
are favorable, vast populations can occur in most of the United States.
Female mosquitoes require a blood meal for egg production,
and they produce a painful bite as they feed.
While feeding, they can transmit a number of disease causing
organisms to humans and animals. The diseases
these organisms cause include: encephalitis, dengue fever,
filariasis, yellow fever, and malaria. Encephalitis,
dengue, and West Nile virus (caused by different mosquito
born viruses) are potential threats in parts of the United States.
There are over 160 different species of mosquitoes in
North America. Most are only nuisance pests and do not
transmit disease, while other species exist without
affecting humans in any way. Four troublesome
mosquito species include Western
Encephalitis Mosquito (Culex tarsalis), Yellow Fever
Mosquito (Aedes aegypti), Malaria Mosquito( Anopheles
freeborni) and Southern House Mosquito (Culex
- Mosquitoes need water to complete their life cycle, so remove all possible water sources. Check flowerpots, birdbaths, pet watering bowls and other containers for excess water. Store boats, canoes and other objects so that they do not collect rainwater. Keep rain gutters free of leaves and other debris that prevent water from draining. Correct drainage problems in yards and playing fields to prevent rain and irrigation water from pooling for prolonged periods. Fill holes or depressions in trees with sand or mortar. Repair leaky pipes and outside faucets. Correct or report drainage problems in ditches along public or private roadways.
- For water, or structures that cannot be removed, mosquitoes can still be eliminated from them by careful maintenance. Replace water containers for pets, birdbaths and fountains every few days. Maintain swimming pools correctly. For ponds, Gambusia (mosquito-eating fish) can be introduced in some areas. Be sure you know about any ordinances that prohibit release of fish into outside water bodies.
- Pesticides can be used to kill adult mosquitoes. Applications of some pesticides sprayed on vegetation, tree trunks, building walls and catch basins will control certain adult mosquito species.
Bacillus thuringiensis israelensis, or Bti, and Bacillus sphaericus (Bs) are common soil-inhabiting bacterium that are commercially available. This bacterium kills mosquito larvae but will not harm fish, birds, pets or other wildlife.
- Some synthetic pesticides mimic the insect juvenile hormone. When this is present, the development of the mosquito larvae is disrupted, and they do not develop to the adult stage. Mosquito Control Districts use these pesticides in situations like cisterns and abandoned swimming pools. Some are toxic to fish.
- In some areas, bats and birds consume mosquitoes as part of their natural diet. Incorporating nesting boxes around your property will attract these natural predators to the area. However, the feeding activity of insect-eating bats and birds will not be sufficiently selective to cause complete reduction of mosquito populations, but every bit helps. Please monitor bird and bat boxes regularly as bees can invade the boxes and develop hives.
- Keep mosquitoes out of the home by installing and maintaining tight fitting window and door screens.
- Some personal protection from mosquitoes can be achieved using insect repellents. Repeated use of repellents over a short period (several days) is not recommended, especially for pregnant women and children. The consumption of certain natural substances including garlic and the vitamin B complex is reputed to reduce the number of bites. Nevertheless, there is no scientific evidence to confirm their effectiveness.
Heartworms in Dogs
Mosquitoes also transmit heartworm in dogs. Heartworm
can cause severe circulatory problems and produce
symptoms such as coughing, labored breathing
and general loss of vitality in advanced stages. Because
of the impracticality of protecting dogs from
mosquito feeding, the most effective means of controlling
heartworm is to prevent worms from reaching
the adult stage inside the dog. Veterinarians can
prescribe excellent drug treatment to protect pets from
Because some mosquito species fly long distances from
breeding sites, a community-wide effort may be
needed to reduce mosquitoes to tolerable levels. This
requires the formation of a local mosquito control program
to organize community-wide management.
Local pest abatement districts can be set up using
property tax dollars to employ a local pest management
professional team to coordinate control strategies.