the stage in the life cycle of a mosquito in which moulting takes place
Answers
The mosquito goes through four separate
and distinct stages of its life cycle: Egg, Larva, Pupa, and Adult. Each
of these stages can be easily recognized by its special appearance.
Egg : Eggs are laid one at a time or attached together to form "rafts." They float on the surface of the water. In the case of Culex and Culiseta species, the eggs are stuck together in rafts of up to 200. Anopheles, Ochlerotatus and Aedes, as well as many other genera, do not make egg rafts, but lay their eggs singly. Culex, Culiseta, and Anopheles lay their eggs on the water surface while many Aedes and Ochlerotatus lay
their eggs on damp soil that will be flooded by water. Most eggs hatch
into larvae within 48 hours; others might withstand subzero winters
before hatching. Water is a necessary part of their habitat.
Larva: The
larva (plural - larvae) lives in the water and comes to the surface to
breathe. Larvae shed (molt) their skins four times, growing larger after
each molt. Most larvae have siphon tubes for breathing and hang upside
down from the water surface. Anopheles larvae do not have a siphon and
lie parallel to the water surface to get a supply of oxygen through a
breathing opening. Coquillettidia and Mansonia larvae
attach to plants to obtain their air supply. The larvae feed on
microorganisms and organic matter in the water. During the fourth molt
the larva changes into a pupa.
Pupa: The pupal
stage is a resting, non-feeding stage of development, but pupae are
mobile, responding to light changes and moving (tumble) with a flip of
their tails towards the bottom or protective areas. This is the time the
mosquito changes into an adult. This process is similar to the
metamorphosis seen in butterflies when the butterfly develops - while in
the cocoon stage - from a caterpillar into an adult butterfly. In Culex species
in the southern United States this takes about two days in the summer.
When development is complete, the pupal skin splits and the adult
mosquito (imago) emerges.
Adult: The newly
emerged adult rests on the surface of the water for a short time to
allow itself to dry and all its body parts to harden. The wings have to
spread out and dry properly before it can fly. Blood feeding and mating
does not occur for a couple of days after the adults emerge.