How Do Asian Tiger Mosquitoes Affect the Native Species?

Asian tiger mosquitoes are about a quarter-inch long, easily identified by their white-spotted bodies and black-and-white-striped legs. They reproduce quickly in warm, moist environments, displacing the common native mosquitoes. Females can lay up to 300 eggs in a few weeks. They breed in tiny pockets of water found in tree holes, discarded tires, cans and other containers. Asian tiger mosquito eggs aren't harmed by cold or dry weather; they lie dormant, awaiting warm, moist hatching weather.

Asian tiger mosquitoes may bite throughout the day, but they behave more assertively in early mornings and evenings. They deliver painful bites to birds, humans and other native mammal species, such as dogs, cats and horses. They're known to swarm in large numbers, acting aggressively when they're in a feeding frenzy. High concentrations of hungry mosquitoes make being outdoors difficult for humans and pets in infested areas.

Female Asian tiger mosquitoes need blood as a protein source necessary for egg production. After piercing a host's skin, she injects saliva into the bloodstream before drawing blood. This prevents the blood from clotting in her small food canal. Native animals, including birds and humans, suffer itchy, raised welts that may last a few hours or several days, depending on the severity of allergic reaction to the female mosquito's saliva in the host.

Asian tiger mosquitoes are carriers of many diseases and protozoa, such as West Nile virus, dengue fever, yellow fever, eastern equine encephalitis and canine heartworm disease. Large Asian tiger mosquito populations make it difficult to control and eradicate mosquito-borne diseases once they're introduced. Eastern equine encephalitis is carried from passerine birds to mammals by Asian tiger mosquitoes. Humans are rarely infected by eastern equine encephalitis, but it's prevalent among horses in areas where Asian tiger mosquito populations are established.