Mosquito Basics

About mosquitos

Mosquitoes are members of the family Culicidae in the order Diptera (true flies). Adult mosquitoes are distinguished from other flies by the presence of a long proboscis and scales on the margins and veins of the wing. Males differ from females by having feathery antennae and mouthparts not suited for piercing skin.

Mosquito life cycle

Mosquitoes are insects that develop through four distinct life stages - egg, larva, pupa and adult. Only adult females feed on blood which is a required source of protein for egg development. Males and females feed on plant nectar as a source of carbohydrates.

Mosquito eggs

There are three basic types of mosquito eggs - those laid singly on the water surface, each egg being buoyed by floats; eggs laid on the water surface in groups or rafts; and eggs laid singly out of the water on a surface that will subsequently flood. 

Mosquitoes which deposit eggs on the water surface are commonly known as permanent water breeders and include the genera Anopheles,Coquillettidia, Culex and Culiseta. 

Floodwater mosquitoes lay their eggs on a moist substrate, out of the water, and represent one of the most successful reproductive strategies in the animal kingdom. Female floodwater mosquitoes are attracted by chemical stimuli to oviposition sites and are not dependent on water for oviposition, hence weather has less impact on the reproductive success of floodwater species than on permanent water breeders. Floodwater mosquito genera include Aedes, Ochlerotatus and Psorophora.

Mosquito larvae

All mosquito larvae are aquatic. The 60 species known to occur in Maryland have adapted to a wide range of larval habitats, including swamps, marshes, tree holes, septic ditches, rock pools, etc. All of the breeding sites have a common characteristic of stagnant pools not subject to significant wind or wave action or water flow. Additionally, the breeding sites generally have a low or non-existent population of parasites or predators that prey on mosquito larvae. Consequently, flowing streams, tidal creeks, large ponds, lakes and other large water bodies are not typical mosquito breeding sites. Larvae feed on microorganisms and particles of organic matter. Mosquito larvae must have access to atmospheric oxygen, which is obtained by means of a siphon tube that penetrates the water surface or, in some species, pierces the roots of aquatic plants. The larval stage lasts from 4 to several days and contains four separate developmental periods termed instars.

Mosquito pupae

The pupal stage is also aquatic but the pupa can complete development on a moist surface. It is during the pupal phase that the transformation from an aquatic larva to a terrestrial adult takes place. The pupal stage lasts only a few days.

Adult mosquitos

Adult female mosquitoes mate once during their lifetime. This occurs shortly after emergence from the pupal case. 

The blood feeding habits of the female vary between species. Some are general feeders while others feed only on specific groups of vertebrates such as birds or reptiles. 

The flight habits are also variable, with some species rarely flying more than several hundred feet from their breeding sites and others flying 20 miles or more.