|
| Consumers Guide to Mosquito Control Products | Mosquito Control |
Consumers Guide to Mosquito ControlClosing the Buffet! Table of Contents IntroductionTopical Application and Clothing DEET Habitat Control (through chemical and biological means) Mosquito Control Devices Viruses - and Their Symptoms Q&A (or “Did you know…”)
IntroductionYou lie in the quiet darkness of your room, waiting to fall asleep! Suddenly, you hear the aggravating whine of a mosquito buzzing in your ear. It’s there and then it’s gone! Several minutes go by and you begin to drift off. Buzz! You hear it again. You swat at the empty air, hoping to banish the little monster. Finally, you retreat under the sheet, hoping to avoid the painful bite of the pesky creature. Mosquitoes also make outdoor activities miserable experiences. While you have fun outdoors, many insects get to enjoy a good meal. Either they're eating your food or they're eating you. To clear your yard of these insects, you can try a variety of devices, ranging from simple Citronella candles to elaborate traps to pesticides (such as Dursban) to electronic bug zappers. This Guide will help you prepare for that little biting pest, who as we’ve learned, can be more than an itchy nuisance - it can be a nasty disease carrier, with germs for West Nile Virus, Yellow Fever, Lime Disease, Malaria, Dengue Fever, Encephalitis, and Rift Valley Fever. Want to learn more? Read on…
Topical Application and ClothingN,N-diethyl-3-methylbenzamide (DEET) - Repellants containing DEET (N, N-diethyl-m-toluamide) are the best to use. The more DEET a repellent has, the longer it protects against mosquitoes. The higher percentage of DEET does not mean that you have more protection; it only means that you have longer protection. DEET does not kill the mosquitoes that bite you; rather, it just repels them. D eet is generally acknowledged as the most effective mosquito repellent there is. Generally, products with about 30% deet have proven most effective for the longest periods, and they are considered safe for adults and children age 2 months and older. Permethrin - This is an artificial insecticide that is very similar to pyrethrum, which is a chemical that occurs naturally from nature. This chemical was created from dried and crushed flowers from the daisy Chrysanthemum. The Chrysanthemum has properties that act as an insecticide which have been well noted since the beginning of the 18 th century. In the 1970s this produce was synthesized and sold to customer. Permethrin actually works on first contact. It damages mosquitoes by harming their nervous system when they come in contact with it. This kills the mosquitoes. There have been some studies which show that bednets treated with permethrin can actually decrease the risk of developing malaria.
Permethrin Vs. DEET: Can They Be Used Together?While permethrin and DEET do complement each other, they can not be used interchangeably. Why? DEET works by actually repelling insects that bite; it blocks the receptors on the antennae of insects which allow the insect to locate a host. Permethrin does not actually repel insects. Instead it works by killing or stunning any bugs that come into contact with the substance. You will get the most protection by wearing DEET on any skin you have exposed and permethrin on your clothing. Typically using DEET with an extended duration system and premethrin treated clothing is the regimen used by the U.S. military in areas where illness due to insects is a serious threat. Avon's Skin-So-Soft -- The proprietary bath oil Avon Skin-So-Soft reportedly has some small measure of repellency against the yellow fever mosquito, aedes aegypti. Extensive laboratory tests have shown, however, that DEET (N,N-diethyl-m-toluamide, the chemical found in almost all commercial insect repellents and their DOD counterparts) is about 30 times more repellent than an equal amount of Skin-So-Soft. In addition, Skin-So-Soft's repellency is effective for only about 1 1/2 hours, whereas an equal concentration of DEET will effectively repel mosquitoes up to four hours.
“Natural” RepellentsCatnip oil may be more effective than products containing DEET, although it is not as long lasting. Citronella, catnip, lavender, and others are similarly effective, but all have short effectiveness. Joel R Coats, Entomology, Iowa State University says, "The essential oils may not provide as long of a residual protection, but they can repel for two hours -- so there would be trade-offs for people preferring the natural oil, or that don't plan to stay out for 6 hours, or don't mind reapplying it every couple of hours, or prefer using it on kids." Citronella candles and incense work best if there is relatively little air movement, but are otherwise useless. Research shows many products, such as wrist bands and pins with repellent, brewer's yeast, and vitamin B1, to be of little or no value, although some people swear by them.
Habitat Control (through chemical and biological means)The decision on which pest management techniques are most appropriate depends on a sampling of which mosquito species are present. Generally, source reduction -- eliminating or altering the water in which mosquitoes breed - is the first choice for control. If this cannot be achieved effectively, then the second choice to consider would be biological control of the larvae with predators, bacterial insecticides, or growth regulators. Source ReductionThe fact that all mosquitoes require water to develop is the key to their control! No standing water means no mosquitoes. If we can reduce the breeding habitat we are a long way to winning the battle. On the homeowner/community level: dispose of any container around the home containing standing water, fill in areas with standing water, ponding and the introduction of fish, clean roof gutters (watch for standing water), check children's toys, bird baths, plastic covers, and so on. Biological ControlsMosquito-Eating Fish -- Fish are the most important predator to larvae. Of course this control is only useful on a larger scale or on ponds created and managed by a home owner. Gambusa affinis, an inch-long freshwater fish that can tolerate contaminated waters eats hundreds of larvae an hour. The killifish also eats larvae but is less tolerant of fetid waters. Bacterial Insecticides -- Products containing Bacillus thuringensis israelensis (Bti) are available for treating bodies of water. This bacteria kills mosquito and black fly larvae. It is harmless to humans, other animals, fish, and predacious insects. It is only effective against larvae since it needs to be ingested. At the community level it is available as so called Mosquito Dunks. Natural Enemies -- Mosquito larvae are an important food for aquatic organisms. Fish, insects, and spiders pray on them. Adult mosquitoes are fed upon by birds, bats, frogs, spiders, and insects (one example is the dragon fly). Chemical Control of MosquitoesGrowth Regulators -- Insect growth regulators do not kill the larvae, but prevent them from developing into adults. Application can be difficult since only mature larvae are affected. Most growth regulators do not harm other non-target species. Larviciding -- Petroleum oils and mineral oils can be applied to the water. The resulting oil film over the surface suffocates the eggs, larvae, and pupae. Rain, wind, waves may break up the oil film and makes it less effective. Some oils are toxic to fish, plants or other organisms. Adulticiding -- Adulticiding is space spraying for adult mosquitoes with insecticides. It is considered the least effective method since it does not control the source. It can only provide temporary relief and non-selectively kills all insects. Adulticiding is considered only effective where mosquitoes pose a health threat.
How to Prevent Mosquitoes from Breeding Around Your HomeMosquito larvae, which are often called “wrigglers” have to survive in still water for at least five days in order to completely develop and form before they transform into their adult biting counterparts. Only adult mosquitoes can transmit diseases. Very often you can reduce the number of mosquitoes in an area by removing any areas that have standing water. One small pile of still water can result in hundreds of biting mosquitoes. Fortunately there are several things you can do to eliminate sources of standing water and thus mosquitoes:
Only a constant, complete program to control mosquitoes will reduce the numbers, the nuisance, and the danger of disease.
Mosquito Control DevicesToday's concern over the environmental effects of pesticides has brought about renewed interest in control devices. Some of the more popular control measures are outlined below. Mosquito Magnets -- The mosquito magnet works 24 hours a day by emitting carbon dioxide, heat, and moisture to attract biting insects, while simultaneously vacuuming the insects into a net where they dehydrate and die. The traps are silent, odorless and don't cause any mess. Why do mosquitoes love to feast on some people, while others escape without a bite on them? Mosquitoes are attracted to humans through the carbon dioxide they exhale when they breathe. Human carbon dioxide or C02 production varies depending on your metabolic rate: if your metabolism is high you tend to burn more C02 and are more attractive to mosquitoes. In addition to carbon dioxide, mosquitoes are also attracted to: Lactic Acid -- released after a workout or after eating salty and high-potassium foods. Bug Zappers -- A bug zapper, more formally known as an electronic insect-control system or electrical-discharge insect-control system, lures bugs into it and kills them with electricity. Most zappers use fluorescent light that attracts insects -- usually mercury, neon or ultraviolet (black light). As the bug flies toward the light, it penetrates the space between the wire-mesh grids of the zapper, and completes the electric circuit. High-voltage electric current flows through the insect and vaporizes it. You often hear a loud "ZZZZ" sound when this happens. Bug zappers can lure and kill more than 10,000 insects in a single evening. By design, bug zappers do not discriminate between types of insects, but because of their luring strategy, they tend kill those insects that are most attracted to ultraviolet light. Mosquitoes, unfortunately, are not attracted to ultraviolet light. Ultrasonic Devices - Ultrasonic devices include products that are designed to be worn around the neck or wrist, or attached to a belt, to repel mosquitoes. The devices create sounds that mimic male mosquitoes or dragonflies and theoretically will "frighten" the female mosquitoes. Most of these products are battery-operated, cost from $10 - $20, and include bracelet, key chain, and tabletop models. According to the Federal Trade Commission (FTC), there is no competent or reliable evidence to support the claims made for the products, and that the claims are false. Mosquito Misting Systems - decrease the bug population by intermittently misting the area you define with a misting concentrate. The misting system uses a low-toxicity level solution of Pyrethrum (Chrysanthemum cinerariaefolium), which is an organic insecticide made from crushed flowers. Misting nozzles are installed and the lines run from a reservoir containing the misting concentrate. A timer mechanism is located on the lid of the reservoir, and can be set to mist based on anticipated need. Systems which include a remote control may be used to mist between scheduled times if necessary. Systems which include a rain sensor, wind sensor, and/or freeze sensor ensure the system does not unnecessarily mist during inclement weather. The misting lines and nozzles are easily installed around the perimeter of your home or other structures and can be installed with a zone design to allow specific zones to be turned on and off manually while other zones remain active. Nozzles can be placed along fence lines, trees, flowerbeds and decking. One of the advantages to a mosquito misting system is that it does not attract the bugs to your yard, but simply repels/kills the bugs that are already there. Mosquito Dunks - Dunks are able to kill mosquito larvae long before they have a chance to develop into full blown mosquitoes. They work by releasing a larvicide called Bti. They typically work quickly, reducing or completely eliminating mosquito populations within 24 hours of contact. Typically these dunks can treat as much as 100 square feet of surface water, no matter what the depth is. Dunks usually last 30 days or longer, and can be distributed over small areas. They don’t expire so you can keep them for long periods of time. Mosquito Netting -- Mosquito nets are a very useful and practical way to prevent insect bites. There are a number of things to keep in mind when buying a mosquito net. The mesh size should be large enough for air circulation but as small as possible to keep out the mosquitoes. A mesh size of 1.2 mm x 1.2 mm is the most common and recommended. For effective malaria protection, the mesh size that is recommended is 120-200 holes per square per inch. As for the shape of the net, it should obviously be wide enough to cover the person sleeping, without touching them. Rectangular nets offer more room around the person as opposed to the slanted sides of a tent or pyramid shaped net. Either way, the net should be tucked under the mattress. You can use screws, tacks, pins, or hooks to attach the upper point of the net above the bed. Pillows or blankets can be used to build a makeshift wall around the body to avoid touching the net. It is much more efficient to purchase a net that has already been dipped or sprayed with a high quality insecticide such as permethrin. The nets are pre-treated at the netting manufacturing plant and can last up to a year depending on the amount of exposure to sun and rain. Purple Martins -- Certain species of birds consume high numbers of flying insects, particularly purple martins. There are many that encourage the use of these species for mosquito control, however this notion is often refuted by individuals including J.L Wade, a less well known ornithologist who suggested that purple martins would have to consume at least 14,000 mosquitoes per day in order to actually survive and act as a pest control system. In all reality purple martins consume large number of other insects, not just mosquitoes. Unfortunately purple martins also consume dragonflies, which is unfortunate since this flying insect actually eats mosquitoes as well. In addition purple martins typically feed at or above the treetop level at night, which is above the height most mosquitoes fly at. In all reality purple martins cannot be considered an adequate form of pest control. Bats - Of late a great deal of attention has been given to bats because of their habit of ingesting mosquitoes. Believe it or not during the 1920s near San Antonia several towers were built to attract bats in order to help minimize the spread of mosquitoes carrying malaria. However, the mosquito populations didn’t decrease in number thus the project was abandoned. This is perhaps because bats feed mostly on beetles, moths and other larger flying insects. Bats do not specialize or consume only one particular type of insect, but rather will consume whatever insects are available at the time they are feeding. However, if no other food was available it is likely that bats would be happy to consume only mosquitoes. It’s unrealistic to assume however that this would be the standard practice for the species. Mosquito Plants - A new plant is being marketed to people as the “cure” for mosquitoes. Called the citrosa geranium, researchers discovered this plant in the Netherlands. The plant is said to carry a gene that is capable of producing the scent produced by citronella oil. This is a weak but relatively popular form of mosquito repellent. The plant has been tested by the Dept. of Environmental Biology in Canada, that determined that the citronella oil isn’t released unless the leaves are rubbed on or crushed on the skin. Generally this might be considered a ‘weak’ protection from mosquitoes.
Viruses - and Their SymptomsWest Nile VirusThe West Nile Virus is one of the better-known mosquito born illnesses today, most commonly found in areas of the world including Africa, the Middle East and West Asia. As of 1999 the virus was detected in the U.S First detected in New York, the virus has spread to all regions of the United States with the exception of just a few states including Hawaii. Risk Factors for West Nile West Nile is commonly caught when a mosquito carrying the disease bites someone. Mosquitoes typically contract the disease by feeding on a bird that is infected with it. The virus circulates within the mosquito eventually landing in the salivary glands. When the mosquito bites a human, it is able to transfer the virus to humans. The most common symptoms of West Nile are flu-like, though many people infected will not experience any adverse effects at all. Symptoms may include body aches, fever, headaches and even swollen glands, though the disease can progress into a more severe form of encephalitis or meningitis, or even a condition called meningoencephalitis. These conditions are dangerous because they involve inflammation of the brain, surrounding lining or both. Symptoms of these more severe forms of West Nile may include a stiff neck, fever, headache, disorientation, and even coma or paralysis. If a person has a mild form of the disease their symptoms will likely last only a few days; however, more severe forms of the disease may result in permanent neurological changes or damage. Yellow FeverThis type of viral infection is considered a tropical disease that can be spread to humans via infected mosquitoes. Typically infections with yellow fever are considered mild, but the disease can result in a severe, life threatening illness. Yellow Fever is spread when mosquitoes are infected by biting other people. Typically a specific type of mosquito, called the Aedes aegypti, carries the virus between humans. These mosquitoes are accustomed to living in urban areas including towns and cities. They often breed in tires that have been discarded, old flowering pots and any other type of water storage container located near homes and dwellings. Mosquitoes generally inject the virus into humans at the moment of biting. Symptoms In general, the signs of yellow fever are mild. However the disease can progress into a severe infection. The signs of a serious infection may include chills, a high fever, vomiting and nausea, backache and chills. The infection can sometimes be severe enough to result in shock, kidney failure, liver failure or bleeding. Yellow fever actually gets its name from the yellowing that occurs in the skin when the liver is affected. A blood test is necessary to diagnose yellow fever. Symptoms typically will begin within the first week of exposure. MalariaMalaria is caused by a parasite that is transmitted by an Anopheles mosquito. The parasite grows in your bloodstream and can produce symptoms that develop anywhere from six to eight days to several months after infection. Symptoms The symptoms include fever, chills, headaches, muscle aches and general malaise (similar to flu symptoms). Malaria is a severe disease that can be fatal, but can be treated with antimalarial drugs and prevented by vaccinations. Malaria is prevalent in tropical or sub-tropical climates. Dengue FeverDengue is primarily a disease of the tropics, and the viruses that cause it are maintained in a cycle that involves humans and Aedes aegypti, a domestic, day-biting mosquito that prefers to feed on humans. Dengue fever is a mild viral illness transmitted by mosquitoes. It is characterized by fever, rash, and muscle and joint pains, whereas Dengue hemorrhagic fever is a severe, potentially fatal infection that occurs when someone with immunity to one type of Dengue virus is infected by a different type. EncephalitisEncephalitis is an inflammation of the brain that can be caused by viruses. The symptoms of encephalitis can range from mild to severe. Severe symptoms include rapid onset of severe headaches, high fever, and mental disturbances such as confusion, irritability, tremors, stupor and coma. Severe cases sometimes end in death or with survivors suffering permanent loss of limb function, reduction of intelligence and/or emotional instability. The Encephalitis virus is classified in seven distinct types, including:
St. Louis (SLE) -- St. Louis encephalitis (SLE), named for the city where the first cases were recognized in 1933, is the most common variety of viral encephalitis in the USA. The virus that causes St. Louis encephalitis in humans is thought to occur naturally in birds. It is transmitted among birds and between birds and other animals by blood-feeding mosquitoes. The SLE virus is not known to cause disease in birds and once infected individual birds are immune to further infection. Most people who are infected with St. Louis encephalitis never show any symptoms. Mild cases may occur with flu-like symptoms, a slight fever and headache. Severe infections are marked by a rapid onset, headache, high fever, disorientation, coma, tremors, convulsions, paralysis or death. Japanese (JE) -- Japanese encephalitis is a mosquito-borne disease caused by the Japanese encephalitis virus. It occurs mainly in the rural and agricultural areas of Asia and the Western Pacific. Over 50,000 cases are reported annually from Southeast Asia, India, China, Japan and Korea. In temperate regions such as China, Japan and Korea, the transmission is highest from April to September. In northern India and Nepal, peak transmission is from June to November. In the tropical regions of Asia and Oceania, JE occurs year-round. Most infections are asymptomatic. Only 1 in 250 infected individuals become sick. The incubation period is about 4-14 days. Usual symptoms include headache, fever, nausea and vomiting. Severe cases may progress to confusion and coma. The mortality can be as high as 35%. About 30% of those who survive may have severe nervous system damage like paralysis. La Crosse (LCE) - The La Crosse Virus is an arbovirus (a virus transmitted by insects); it is one of the most important mosquito-borne viruses in the United States. It is found in all thirteen States east of the Mississippi River. Encephalitis caused by this virus is most common in children and young adults (those under the age of 19). Patients may have all or some of the following symptoms: fever, vomiting, stiff neck, headache, lethargy, seizure, and even coma. There is no specific therapy, but most patients recover (death is less than 1%). As mentioned, this virus is transmitted by mosquitoes ( Aedes species). These are “tree hole” mosquitoes that lay their eggs in water-holding containers like old tires and tree holes. The primary reservoirs of the virus are small forest mammals (like the eastern grey squirrel and chipmunks). Eastern Equine (EEE) -- Eastern equine encephalitis (EEE) is caused by a virus transmitted to humans and equines by the bite of an infected mosquito. EEE virus is an alphavirus that was first identified in the 1930's and currently occurs along the eastern seaboard, the Gulf Coast, and some inland Midwestern locations of the United States. While small outbreaks of human disease have occurred in the United States, equine virus problems can be a common occurrence during the summer and fall. Symptoms: It takes from 4-10 days after the bite of an infected mosquito for an individual to develop symptoms of EEE. These symptoms begin with a sudden onset of fever, general muscle pains, and a headache of increasing severity. Many individuals will progress to more severe symptoms such as seizures and coma. Approximately one-third of all people with clinical encephalitis caused by EEE will die from the disease and of those who recover, many will suffer permanent brain damage with many of those requiring permanent institutional care. Western Equine (WEE) -- Western Equine Encephalitis is a virus that results from mosquito bites that typically occurs in California, and generally reaches levels that can be detected once every few years. This disease is sometimes referred to as sleeping sickness. It can be a very severe disease affecting the brain. Typically the disease becomes problematic when it affects horses and humans. Between the years 1945 and 1987 there were more than 700 cases reported in California. The number of people affected from this virus generally varies significantly from year to year, however more commonly infants or the elderly are affected. Most people will not have any symptoms for a week or more after being bitten. Many people will show no sign of the disease at all, though some will show signs such as nausea, fever, vomiting or headache. In some patients it isn’t uncommon for meningitis like signs and symptoms to occur. This can include a stiff neck accompanied by a fever that lasts up to 10 days. In a very small percentage of patients WEE will result in encephalitis, which can result in serious complications including coma or death. Hospitalization is required if encephalitis occurs. Venezuelan Equine (VEE) - Venezuelan equine encephalitis is a virus that is common to regions such as Central America, Mexico, Florida, South America and Mexico. This virus typically causes severe disease in animals including horses, donkeys, mules and burros. When human outbreaks occur they often result in fatal encephalitis. Onset of this disease is typically swift and may include a high fever, photophobia, and pain in the legs, cough, sore throat and even diarrhea. This may only last up to 3 days, followed by a period of prolonged fatigue. Some children may develop central nervous system complications including paralysis and convulsions. Adults infected with this disease typically will not develop neurological complications. Rift Valley FeverRift valley fever is a fever-causing disease that affects livestock (including cattle, buffalo, sheep, and goats) and humans in Africa. It is named after a trough stretching 4,000 miles from Jordan through eastern Africa to Mozambique. Rift Valley fever is spread mainly by infected mosquitoes and appears most often during years of heavy rainfall. What are the signs and symptoms of Rift Valley fever? People with Rift Valley virus infections typically have a flu-like illness with fever, weakness, back pain, dizziness, and weight loss. Infected people usually get better in 2 days to 1 week after the start of the illness. Sometimes, however, the infection can cause hemorrhage (severe bleeding), encephalitis (inflammation of the brain), or severe eye complications. Who is at risk for Rift Valley fever?
Q&A (or “Did you know…”)Can I get AIDS from a mosquito bite? No! One of the most prevalent myths about HIV transmission is that mosquitoes or other bloodsucking insects can infect you. There is no scientific evidence to support this claim. To see why mosquitoes don't aid in the transmission of HIV, we can look at the insect's biting behavior. When a mosquito bites someone, it does not inject its own blood or the blood of an animal or person it has bitten into the next person it bites. The mosquito does inject saliva, which acts as a lubricant so that it can feed more effectively. Yellow fever and malaria can be transmitted through the saliva, but HIV does not reproduce in insects, so the virus doesn't survive in the mosquito long enough to be transmitted in the saliva. Additionally, mosquitoes don't normally travel from one person to another after ingesting blood. The insects need time to digest the blood meal before moving on. What can I do to prevent mosquito bites? Try these tips:
Here are some common sense rules to follow when using mosquito repellents:
GLOSSARY of Termsalphavirus -- Alphaviruses are viruses that attack the brain. There are three main types: 1) eastern equine encephalomyelitis (EEE); 2) Venezuelan equine encephalomyelitis (VEE); and 3) western equine encephalomyelitis (WEE). Bti -- Mosquito Dunks contain Bacillus thuringiensis subspecies israelensis (B.t.i.). B.t.i. is a bacterium toxic to Mosquito and black and psychodid fly larvae. meningoencephalitis -- Combination of encephalitis (inflammation of the brain) and meningitis (inflammation of the lining of the brain and spinal cord), both of which can be fatal. N,N-diethyl-3-methylbenzamide (DEET) -- the most effective, and best studied, insect repellent currently on the market. This substance has a remarkable safety profile after 40 years of worldwide use, but toxic reactions can occur (usually when the product is misused). When DEET-based repellents are applied in combination with permethrin-treated clothing, protection against bites of nearly 100% can be achieved. Dursban -- Chlorpyrifos (the chemical name for Dursban) is an organophosphate type of insecticide. flavivirus -- A group of disease-causing viruses known as flaviviruses, which are spread by insects, usually mosquitoes and ticks. Foremost among these is Yellow Fever Virus, the type virus of the Flaviviridae, from which the family begets its name ( flavus in Latin means "yellow"). hemorrhagic - (Or Hemorrhagic Fever) -- A viral infection (usually restricted to a specific geographic area); fever and gastrointestinal symptoms are followed by capillary hemorrhage. insectivorous -- Insect and larva-eaters; depending on insects as food. opportunistic feeders --Animals that eat whatever food is convenient at the time. organophosphate (sometimes abbreviated OP) -- is the general name for any organic compound containing phosphorus.
|
News n' Info Mosquito Control GuideHave questions? We've got answers! Visit our consumers guides to mosquito control to learn everything you ever wanted to know about mosquito control products! Feature Articles Mosquitos And How To Control ThemWhat you can do to help control mosquitos around your home. Pesticides and Mosquito Control General information on mosquito control using pesticides and by non-chemical methods.
 |
|
