We become especially aware of mosquitoes every summer while outdoors in the warmer months. Sometimes we see full swarms or just a single mosquito and know that they are ready to drink some blood and cause itches and irritations to our skin.
Other than being a major nuisance, mosquitoes can be a real threat to your health. Mosquitoes can carry a number of illnesses that are a serious threat to both humans and animals. Over a short period of time, for instance, the West Nile Fever has been brought to the United States and has now infected people in every state. A single mosquito bite can also cause malaria, dengue fever, and encephalitis. Because they drink the blood of animals and humans, they can easily get infected and then pass that infection on to another creature.
More than 2,500 species of mosquitoes are recognized worldwide. Most mosquitoes in the US belong to the genera Aedes, Anopheles, Culex and Psorophora. Mosquitoes are distinguished from all other gnats and flies in the adult stage by the combination of their piercing and sucking mouthparts being elongated into a distinctive proboscis, and the veins and margins of their single pair of wings being covered with scales.
Only the female mosquito will drink your blood, as the male mosquito does not require blood. Mosquitoes, in general, do not need blood to live, as they actually feed on nectar. The female needs blood to help in the process of laying her eggs. Once the eggs are laid, a female mosquito will seek out more blood in order to lay more eggs. She will do this throughout her short life span, which lasts about two weeks.
Mosquitoes are responsible for more human deaths than any other insect. This means that mosquito control is a must for human health and well-being. There are several varieties of mosquitoes, and some are capable of carrying more deadly diseases than others.
Mosquito insecticide is often used on a wide-scale basis to kill mosquitoes and is usually very effective. A new variety of mosquito - a heartier one that is not bothered by direct sunlight - has come to US shores and has brought West Nile Fever with them. In recent years, especially when West Nile Fever first came to the US, major cities were sprayed day and night to prevent the spread of the disease.
In some species of mosquito, the females feed on humans, and are therefore vectors for a number of infectious diseases affecting millions of people per yea Some scientists believe that eradicating mosquitos would not have serious consequences for any ecosystems.
Adult mosquitoes usually mate within a few days after emerging from the pupal stage. In most species, the males form large swarms, usually around dusk, and the females fly into the swarms to mate.
Males live for about a week, feeding on nectar and other sources of sugar. Females will also feed on sugar sources for energy but usually require a blood meal for the development of eggs. After obtaining a full blood meal, the female will rest for a few days while the blood is digested and eggs are developed. This process depends on the temperature but usually takes 2–3 days in tropical conditions. Once the eggs are fully developed, the female lays them and resumes host seeking.
The cycle repeats itself until the female dies. While females can live longer than a month in captivity, most do not live longer than 1–2 weeks in nature. Their lifespan depends on temperature, humidity, and also their ability to successfully obtain a blood meal while avoiding host defenses.
Mosquitoes are a vector agent that carries disease-causing viruses and parasites from person to person without catching the disease themselves. The principal mosquito borne diseases are the viral diseases yellow fever, dengue fever and Chikungunya, transmitted mostly by the Aedes aegypti, and malaria carried by the genus Anopheles. Though originally a public health concern, HIV is now thought to be almost impossible for mosquitoes to transmit.
Mosquitoes are estimated to transmit disease to more than 700 million people annually in Africa, South America, Central America, Mexico and much of Asia with millions of resulting deaths. At least 2 million people annually die of these diseases.
Methods used to prevent the spread of disease, or to protect individuals in areas where disease is endemic include Vector control aimed at mosquito eradication, disease prevention, using prophylactic drugs and developing vaccines and prevention of mosquito bites, with insecticides, nets and repellents.
There are many methods used for mosquito control. Depending on the situation, source reduction (e.g. removing stagnant water), biocontrol (e.g. importing natural predators such as dragonflies), trapping, and/or insecticides to kill larvae or adults may be used.
As for mosquitoes tendency to bite humans, mosquitoes prefer some people over others. The preferential victim's sweat simply smells better than others because of the proportions of the carbon dioxide, octenol and other compounds that make up body odour. The powerful semiochemical that triggers the mosquito's keen sense of smell is nonanal. A large part of the mosquito’s sense of smell, or olfactory system, is devoted to sniffing out human targets. Of 72 types of odour receptor on its antennae, at least 27 are tuned to detect chemicals found in perspiration.
Visible, irritating bites are due to an immune response from the binding of IgG and IgE antibodies to antigens in the mosquito's saliva. Some of the sensitizing antigens are common to all mosquito species, whereas others are specific to certain species. There are both immediate hypersensitivity reactions (Types I & III) and delayed hypersensitivity reactions (Type IV) to mosquito bites (see Clements, 2000).
There are several commercially available anti-itch medications, including those taken orally, such as Benadryl, or topically applied antihistamines and, for more severe cases, corticosteroids such as hydrocortisone and triamcinolone. Many effective home remedies exist, including calamine lotion and vinegar. A paste of meat tenderizer containing papain and water breaks down the proteins in the mosquito saliva. By using a brush to scratch the area surrounding the bite and running hot water (around 49 °C) over it can alleviate itching for several hours by reducing histamine-induced skin blood flow. Plain household sudsy ammonia is also a good treatment, ammonia being the main ingredient in Tender's AfterBite remedy, especially as a first wash option if applied immediate after multibite exposure.