Asian tiger mosquito

Aedes albopictus (Family Culicidae), the Asian Tiger Mosquito or Forest Day Mosquito, is characterized by its black and white striped legs and small, black and white body. It was native to south-east Asia, and occupied a habitat that spread from Madagascar eastward to New Guinea, and north to the latitude of Korea.

The typical member of the Aedes albopictus has a length of about 5 mm. As with other members of the mosquito family, the female is outfitted with an elongated proboscis that she uses to collect blood to feed her eggs. By contrast the male member of the species primarily feeds on nectar. The female reproduces by laying her eggs in water, which is typically a stagnant pool. However any open container filled with water will suffice.

Invasive species

This particular species is able to survive in a wide range of habitats and conditions. It is generally more aggressive than indigenous mosquitoes, and is outcompeting them. The Asian tiger mosquito has a rapid bite that allows it to escape most attempts by people to swat at it.

Other mosquitoes in North America, such as Ochlerotatus canadensis, have a similar leg pattern. Asian Tiger Mosquitoes were first found in North America in a shipment of used tires at the port of Houston in 1985. Since then they have spread across southern USA, and as far up the East Coast as southern New Jersey. This species is an introduced species in Hawaii as well, but has been there since before 1896.

This mosquito has become a significant pest in many communities because it closely associates with humans (rather than living in wetlands), and typically flies and feeds in the daytime rather than at night or at dusk and dawn. It is a container and puddle breeder, needing only a few ounces of water to breed. It has a short flight range (less than 200 m), so breeding sites are likely to be close by where you find this mosquito.

It has not been implicated as a carrier of West Nile virus, but can carry Eastern Equine Encephalitis. It is also a known carrier of dengue fever in Central America, South America, and the Pacific.

Controlling Asian Tiger Mosquitoes

A lot of futile and risky spraying has been done in the last few years because of the West Nile virus scare. This mosquito is active in the day time and so is identified if people are being bitten in the day time. Most mosquito spraying is done at night and will have little effect on Asian Tiger mosquitoes. (Daytime spraying is usually a violation of label directions because of foraging bees on blossoms in the application area.)

It is however, simple to find and deal with the breeding spots, which are never far from where people are being bitten. Locate puddles that last more than 3 days, sagging or plugged roof gutters, old tires holding water, litter, bird baths, kiddie pools, and any other possible containers or pools of standing water. Flowing water will not be a breeding spot and water that contains minnows is not usually a problem, because the fish eat the mosquito larvae. Dragonflies are also an excellent method of imposing control. Dragonfly larvae eat mosquito larvae in the water, and adults will snatch adult mosquitoes as they fly. Insecticide application that also kills dragonflies may actually cause only a brief suppression of mosquitoes, followed by a long term increase in populations.

Whenever possible, all sources of standing water, even if only a quarter cup, should be dumped every three days. Litter, especially containers in ditches, can hold water after the ditch dries up, and all litter should be cleaned up. Bird baths, wading pools, and any other container that can hold rainwater should be emptied. Rain barrels used for garden irrigation, and many other containers that cannot be dumped can be treated with a spoonful of vegetable oil, which will suffocate mosquito larvae as they try to breathe at the surface.

Any standing water in pools, catchment basins, etc, that cannot be drained, dumped, or treated with a small quantity of vegetable oil, can be periodically treated with Bacillus thuringiensis israelensis. This is a disease organism that only affects the pest insects. It is readily available at farm, garden and pool suppliers.