A community can best handle mosquito problems when an organized abatement district (tax-supported) is established. Qualified personnel with adequate funds can then be hired to conduct an effective mosquito-control program.
Under Illinois law, the Mosquito Abatement Districts Act (70 ICCS 1005/et. seq.) enables voters, by referendum, to organize tax-supported mosquito abatement districts.
In an area without a mosquito abatement district, local community leaders must direct and implement the program themselves; successful programs must have persons who are qualified to direct effective mosquito-control operations.
This fact sheet is intended to assist communities that are not part of an established abatement district.
Mosquito Facts:
Mosquitoes are among the most common pests of people. Their biting is an annoyance and an irritation. They can carry numerous diseases that affect humans and their pets or livestock.
In Illinois, although disease transmission is extremely rare, there are 3 kinds of encephalitis (St Louis Encephalitis, La Crosse Encephalitis and Western Equine Encephalitis) which mosquitoes can transmit to humans, as well as a nematode affecting dogs (dog heartworm).
Although, disease transmission is the most commonly cited reason for considering mosquitoes to be a public health problem, the presence of large numbers of biting pests will influence the physical and mental wellbeing of most people. Mosquitoes also cause economic loss to livestock as a result of blood loss and irritation.
In addition, mosquitoes can reduce recreation activities which will result in a loss of tourist income, and they can depress property values on land adjacent to areas where they are produced. Immature mosquitoes are worm-like creatures called larvae that need to live in water while they feed on the microbes or decaying organic matter.
Depending on the species, the adult female lays her eggs on standing water or in places that later become flooded. Larvae are rarely found in lakes and ponds with deep water and clean margins (without excessive vegetation and stagnant pools) or in flowing water such as streams and rivers.
Mosquitoes can be classified by where the larvae are found:
- floodwater or temporary pool
- tree holes and artificial containers
- standing water
Knowing which type of habitat a mosquito species prefers will help in providing effective control.
Generally, the peak biting periods of mosquitoes occur just before and after dark, and again just before dawn. However, each species has its own peak period of biting activity. Male mosquitoes do not bite, but feed on the nectar of flowers and plant juices.
At other times, outside the biting periods, adult mosquitoes can be found resting in grass, shrubbery, or other foliage. A Synopsis of the Mosquitoes of Illinois by H.R. Ross and W. R. Horsfall published in 1965 as “Illinois Natural History Survey Biological Notes No. 52″ is still used by many mosquito control districts as an aid to developing their own key.
No keys are perfect. In general, it is best to acquire some training in mosquito identification from someone trained in Medical or Veterinary Entomology before attempting to identify mosquitoes. Most trained entomologists develop their own keys and rely on mosquito taxonomists for further help.
Floodwater and temporary pool mosquitoes common to Illinois include the inland floodwater mosquito (Aedes vexans), the saltmarsh mosquito (Aedes sollicitans), and the dark rice-field mosquito (Psorophora columbiae).
The eggs of these mosquitoes, which are laid singly on damp soil, require a drying period and may remain dormant for months, hatching within minutes after being covered by shallow water.
The inland floodwater mosquito breeds in areas subject to flooding, such as marshy areas, low wetlands, or poorly drained areas, and is the most important pest mosquito in the state. The saltmarsh mosquito is found chiefly in southern Illinois in association with improper handling of sulfuretted wastes from strip mines and salt water from oil-field operations.
The dark rice-field mosquito and other closely related species will develop in temporary pools, roadside ditches, shallow depressions, and even wheel and animal tracks that fill up during rains.
Floodwater and temporary-pool mosquitoes:
will complete their development from egg to adult in 8 to 14 days. There can be several generations a season if there is adequate rainfall to flood or inundate their egg-laying sites. Heavy populations occur in 10 days to two weeks after the egg-laying sites are flooded. The adults are persistent biters and will bite throughout the day if disturbed.
Most floodwater mosquito species are strong flyers. Over a period of days, they may migrate several miles from their breeding sites. These factors make the floodwater mosquitoes very serious pests in Illinois.
The tree-hole mosquito Aedes triseriatus:
can be a serious pest near wooded areas, as the females are easily disturbed and will bite throughout the day. Eggs are laid singly just above the water line in tree holes and hollow stumps or artificial containers like old tires.
As rainfall fills these cavities and covers the eggs, the larvae hatch and develop. The tree hole mosquito is a carrier (vector) of LaCrosse Encephalitis.
The Asian tiger mosquito (Aedes albopictus):
is another species which can be found associated with artificial containers, especially old tires. In Asian countries this recent immigrant carries encephalitis or other viruses to humans. It is an aggressive species which feeds throughout the day.
Standing-water mosquitoes:
such as the northern house mosquito (Culex pipiens) and related species, develop in overgrown ponds, stagnant and shaded pools, poorly managed waste-effluent lagoons, catch basins, puddles in drainage ditches, as well as in artificial containers such as old tires, tin cans, children’s toys, bird baths, and roof gutters. These mosquitoes lay their eggs on the surface of the water in groups (rafts).
The mosquito larvae become full grown in about 7 to 10 days and feed on bits of organic matter in the water. The pupae transform into adults in 3 to 4 days. The adult female is ready to bite in another day or two, remaining near the larval development site in order to feed. The northern house mosquito is an important vector of St. Louis encephalitis.
The larvae of Anopheles quadrimaculatus, which was the primary vector of malaria in the eastern United States, are primarily found in permanent fresh water pools, ponds, and swamps that contain aquatic vegetation or floating debris.
The females lay their eggs singly on the surface of the water. Although malaria no longer is a threat in Illinois, the malaria mosquito can be a serious pest near wetlands.
Information Sourced From:
