Mosquito

Introduction

Mosquitoes are well known by most people because of their pesky biting habit. Of greater concern, they are very important as vectors of numerous human diseases such as malaria, yellow fever, filariasis, dengue, and encephalitis. Mosquitoes are distributed throughout the world, including the United States.

Recognition

The adults of the 3 most common genre of mosquitoes can be distinguished as follows:

  1. Anopheles with palps about as long as the beak and rests with body and proboscis in one plane or axis which is at an angle to the surface.
  2. Aedes with palps mush shorter than proboscis and rests with body and proboscis in 2 different plans and body resting on surface.
  3. Culex with palps much shorter than proboscis and rests with body up off but parallel to the surface.

Habits

Mosquitoes have adapted to almost every kind of aquatic situation such as permanent ponds and marshes, temporary flood waters or woodland pools, drainage ditches, and water contained in tree holes, leaves of plants, or artificial containers. The exceptions are flowing streams and the open waters of large streams, rivers, lakes, seas, and oceans. The number of generations per year ranges from 1 where the eggs require cold before hatching, to many in warm climates where most breed continuously.

The larvae of most species feed on small aquatic organisms and organic debris which they strain out of the water with a series of oral brushes. Although quite active, the pupae do not feed. The adult males feed on nectar. Although the adult female also feeds on nectar, females of most species require a blood meal before they can lay fertile eggs. Females require 2 days to digest a blood meal, lay a batch of eggs, and then seek another blood meal.

The flight range of mosquitoes varies with the species, temperature, wind direction, time of year, and distance to blood meal sources. For various species of Aedes, the range of recaptured marked females was from 18 mi along coastal Georgia to 110 mi. at sea off the cost of North Carolina. These records probably represent females which got caught up in wind currents because their normal flight ranges are much shorter, about 5-10 miles.

The time of day in which biting occurs varies with the species. Most medically important species bite at dusk and dawn and also during the night, whereas others bite only at dusk and dawn such as the eastern saltmarsh mosquito. Several species of medical importance bite only during the daytime such as the Asian tiger mosquito, and one species, the yellowfever mosquito, bites during the day but also at dawn and dusk. Some species which normally do not bite during daytime will do so if disturbed, for instance by someone walking through high grass on which they are harboring.