Welcome to the South Lake Mosquito Abatement District (SLMAD) Website. Here you will find information about mosquitoes, the dangers they pose, and how to help prevent them. If you have questions or comments regarding this website, please contact us.
This is the worst year for West Nile virus infections in the U.S. since 2002. As of Aug. 24, 2012 the Illinois Health Department has recorded 41 cases of West Nile virus, with 2 deaths. About 80% of people bitten by West Nile-carrying mosquitoes have no symptoms, the 20% who do develop symptoms have fever, nausea, muscle aches, and other flu-like symptoms. At least 19 neuroinvasive cases have been reported, mainly in the 6 county area around Chicago ("neuroinvasive" means that the virus has caused paralysis, or encephalitis or meningitis, all with the probability of leaving the person with long-lasting or permanent nerve damage or memory loss).
There is no vaccine to protect against West Nile virus, and anti-viral medicines are ineffective. The best way to keep from being infected is to avoid getting bitten by mosquitoes. Current preventive measures in South Lake Mosquito Abatement District include frequent and on-going surveillance, larvaciding and adultciding.
Preventive strategies include (click Read More below to see them):
Many mosquitoes, such as Culex quinquefasciatus, lay their eggs on the surface of fresh or stagnant water. The water may be in tin cans, barrels, horse troughs, ornamental ponds, swimming pools, puddles, creeks, ditches, catch basins or marshy areas. Mosquitoes prefer water sheltered from the wind by grass and weeds.
Culex mosquitoes usually lay their eggs at night over a period of time sticking them together to form a raft of from 100 to 300 eggs. A raft of eggs looks like a speck of soot floating on the water and is about 1/4 inch long and 1/8 inch wide. A female mosquito may lay a raft of eggs every third night during its life span.
Anopheles and many other mosquitoes lay their eggs singly on the water surface. Aedes and Ochlerotatus mosquitoes lay their eggs singly, usually on damp soil. Aedes and Ochlerotatus eggs are more resistant to drying out (some require complete drying out before the eggs will hatch) and hatch only when flooded with water (salt water high tides, irrigated pastures, treeholes flooded by rains, flooded stream bottoms). Anopheles , Culex and Mansonia eggs are susceptible to long periods of drying out.
Tiny mosquito larvae (1st instar) emerge from the eggs within 24 - 48 hours almost in unison.
Mosquito larvae, commonly called "wigglers," live in water from 4 to 14 days depending on water temperature.
Larvae must come to the surface at frequent intervals to obtain oxygen through a breathing tube called a siphon. They are constantly feeding since maturation requires a huge amount of energy and food. They hang with their heads down and the brushes by their mouths filtering anything small enough to be eaten toward their mouths to nourish the growing larvae. They feed on algae, plankton, fungi and bacteria and other microorganisms. They breath at the water surface with the breathing tube up breaking the water surface tension. One mosquito species larva feeds on larvae of other mosquitoes: Toxorhynchites, the largest mosquito known, are predators of other mosquito larvae sharing their habitat. Their larvae are much larger than other mosquito larvae.
Mosquito control can be divided into two areas of responsibility: individual and public. Most often it's performed following the Integrated Mosquito Management (IMM) concept. IMM is based on ecological, economic and social criteria and integrates multidisciplinary methodologies into pest management strategies that are practical and effective to protect public health and the environment and improve the quality of life. IMM strategies are employed in concert with insecticide. These include source reduction, which incorporates physical control (digging ditches and ponds in the target marsh) and biological control [placing live mosquito fish (Gambusia) in the ditches and ponds to eat mosquito larvae]. Other non-chemical control methods include invertebrate predators, parasites and diseases to control mosquito larvae. Adult mosquito biological control by means of birds, bats, dragonflies and frogs has been employed by various agencies. However, supportive data is anecdotal and there is no documented study to show that bats, purple martins, or other predators consume enough adult mosquitoes to be effective control agents.
Pesticides may be applied to control larvae (larvicides) or adults (adulticides). Applications of adulticides or larvicides are made after the presence of mosquitoes has been demonstrated by surveillance procedures. Application is made by prescribed standards. All insecticides must have the name and amount of active ingredient (AI) appearing on the label; examples are DEET and pyrethroids. Check the label before buying. No pesticide is 100 percent safe and care must be exercised in the use of any pesticide. Material Safety Data Sheets (MSDS) contain basic information about a product intended to help you work safely with the material.
An efficient way to control mosquitoes is to find and eliminate their breeding sites. Eliminating large breeding areas (source reduction) such as swamps or sluggishly moving streams or ditches may require community-wide effort. This is usually a task for your organized mosquito control program. They might impound an area of water, establish ditches or canals or control the aquatic weeds (cattails, water lettuce, etc) on a body of water. The second method used by organized mosquito control agencies is larviciding. This utilizes the application of insecticides targeted at the immature mosquitoes - the larvae or pupae. These are applied to bodies of water harboring the larvae. However, since larvae do not usually occupy the entire body of water, larvicides are applied where the larvae are, usually the areas near the shoreline of the lake, stream or ditch. Larvicides differ from adulticides in that they are directed at a limited targeted area, i.e. the body of water and often only that area where the larvae grow and mature. Larvicides are classed as stomach toxins, contact larvicides, surface agents, natural agents and insect growth regulators (IGR). Some examples are listed in the Homeowner section that follows.
Homeowners can take the following steps to prevent mosquito breeding on their own property:
The mosquito goes through four separate and distinct stages of its life cycle: Egg, Larva, Pupa, and Adult. Each of these stages can be easily recognized by its special appearance. Egg : Eggs are laid one at a time or attached together to form "rafts." They float on the surface of the water. In the case of Culex and Culiseta species, the eggs are stuck together in rafts of up to 200. Anopheles, Ochlerotatus and Aedes , as well as many other genera, do not make egg rafts, but lay their eggs singly. Culex, Culiseta, and Anopheles lay their eggs on the water surface while many Aedes and Ochlerotatus lay their eggs on damp soil that will be flooded by water. Most eggs hatch into larvae within 48 hours; others might withstand subzero winters before hatching. Water is a necessary part of their habitat.
Larva: The larva (plural - larvae) lives in the water and comes to the surface to breathe. Larvae shed (molt) their skins four times, growing larger after each molt. Most larvae have siphon tubes for breathing and hang upside down from the water surface. Anopheles larvae do not have a siphon and lie parallel to the water surface to get a supply of oxygen through a breathing opening. Coquillettidia and Mansonia larvae attach to plants to obtain their air supply. The larvae feed on microorganisms and organic matter in the water. During the fourth molt the larva changes into a pupa.
Mosquitoes cause more human suffering than any other organism -- over one million people die from mosquito-borne diseases every year. Not only can mosquitoes carry diseases that afflict humans, they also transmit several diseases and parasites that dogs and horses are very susceptible to. These include dog heartworm, West Nile virus (WNV) and Eastern equine encephalitis (EEE). In addition, mosquito bites can cause severe skin irritation through an allergic reaction to the mosquito's saliva - this is what causes the red bump and itching. Mosquito vectored diseases include protozoan diseases, i.e., malaria, filarial diseases such as dog heartworm, and viruses such as dengue, encephalitis and yellow fever. CDC Travelers' Health provides information on travel to destinations where human-borne diseases might be a problem.
Malaria is an ancient disease probably originating in Africa. The malaria parasite (plasmodium) is transmitted by female Anopheles mosquitoes. The term malaria is derived from the Italian 'mal-aria" or "bad air" because it was thought to come on the wind from swamps and rivers. Scientists conducted much research on the disease during the 1880s and early 1900s. Approximately 40% of the world's population is susceptible to malaria, mostly in the tropical and sub-tropical areas of the world. It was by and large eradicated in the temperate area of the world during the 20 th century with the advent of DDT and other organochlorine and organophosphate mosquito control insecticides. However, more than three million deaths and 300 - 500 million cases are still reported annually in the world. It is reported that malaria kills one child every 40 seconds. In the United States malaria affected colonization along the eastern shore and wasn't effectively controlled until the 1940s when the Anopheles mosquitoes were controlled. A resurgence occurred during the 1960s and early 70s in the United States due to returning military personnel from Vietnam. Anopheles quadrimaculatus was the primary vector of the Plasmodium vivax (protozoa) in the United States (Foote and Cook 1959). Antimalarial drugs have been available for more than 50 years and recently scientists in Britain and the United States have cracked the code of the malaria parasite genome, a step that may help boost the campaign against the disease.
Several EPA-registered products that provide repellent activity sufficient to help people avoid the bites of disease carrying mosquitoes. Products containing these active ingredients typically provide reasonably long-lasting protection:
DEET (Chemical Name: N,N-diethyl-m-toluamide or N,N-diethly-3-methyl-benzamide)
Picaridin (KBR 3023, Chemical Name: 2-(2-hydroxyethyl)-1-piperidinecarboxylic acid 1-methylpropyl ester )
Oil of Lemon Eucalyptus or PMD (Chemical Name: para-Menthane-3,8-diol), the synthesized version of oil of lemon eucalyptus
The active ingredients DEET and Picaridin are considered “conventional repellents.” Oil of Lemon Eucalyptus, PMD, and IR3535 are derived from natural materials. For more information on repellent active ingredients click here.
An enormous amount of consumer interest has been generated by the marketing of new devices designed to attract, then either trap or kill, mosquitoes. The general idea is to reduce the number of questing mosquitoes that would otherwise be afflicting the homeowner. Many products even claim to significantly reduce or even collapse local mosquito populations by decreasing the number of egg-laying females through their capture.
Power supplies for each type of trap vary. Some are totally self-contained, utilizing propane to provide both power and a source of carbon dioxide as an attractant. These units have the advantage of portability, allowing them to be placed at a considerable distance away from home-sites and electrical outlets. This may be an important consideration on larger properties, i.e. those over an acre in area, by allowing mosquitoes to be intercepted long before they come into the vicinity of human activity. This portability comes at a price, though, for the thermoelectric generator that uses excess heat from the combustion process to generate electricity to run the intake fans is quite expensive. Most units rely upon power cords utilizing AC outlets. This limits them somewhat to smaller areas served by extension cords, but their price is commensurately less than their self-contained counterparts.
Introduction. The introduction and spread of West Nile virus in the United States has reawakened an appreciation of mosquitoes as vectors of diseases. The term "reawakened" is used advisedly, for mosquito-borne diseases were once quite prevalent in the United States and, indeed, played a major part in shaping our nation's destiny. Dengue Fever, long a scourge in the tropics worldwide, was in fact first described by Dr. Benjamin Rush in Philadelphia in 1780. Additionally, Yellow Fever caused over 100,000 deaths in 135 separate epidemics in the United States from 1793 until 1900, and as late as 1934, there were 125,566 cases of malaria. These diseases no longer claim victims in the United States as a matter of course largely due to the exemplary efforts of organized mosquito control agencies, in conjunction with an enlightened and effective public health infrastructure. Indeed, the mosquito control profession enjoys a long and proud legacy of community service in its pursuit of improved quality of life and a society relatively free from the ravages of mosquito-borne diseases that have afflicted our country in times past.
Background. The first human isolate of West Nile virus was obtained from woman in the West Nile District of Uganda in 1937, with the transmission dynamics elucidated in Egypt in the mid-1950s. Severe symptoms, including meningitis or encephalitis (inflammation of the spinal cord and brain) was described in elderly patients during an outbreak in Israel in 1957. The ability of WNV to produce severe disease in horses was first noted in Egypt and France shortly thereafter.
Outbreaks of WNV encephalitis in humans noted by CDC ":have occurred in Algeria in 1994, Romania in 1996-1997, the Czech Republic in 1997, the Democratic Republic of the Congo in 1998, Russia in 1999, the United States in 1999-2003, and Israel in 2000. Epizootics of disease in horses occurred in Morocco in 1996, Italy in 1998, the United States in 1999-2001, and France in 2000, and in birds in Israel in 1997-2001 and in the United States in 1999-2002."
Since its introduction into the United States in 1999, West Nile virus has spread southward and westward at an alarming pace, with a total of almost 15,700 human cases and 650 fatalities as of 24 September, 2004. Approximately 20% of human West Nile cases develop West Nile Fever, whose symptoms include fever, headache, tiredness, and body aches, occasionally with a skin rash (on the trunk of the body) and swollen lymph glands. This condition can last anywhere from a few days up to several weeks. Almost 30% of symptomatic human West Nile cases develop a more severe form of neuroinvasive disease characterized by headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis. The neuroinvasive form occurs most often in people over age 50 and some immuno-compromised persons (for example, transplant patients), but can occur at any age in healthy individuals. An in-depth discussion of the disease can be found at the CDC.