The Life Cycle Of Mosquito - An insect with complete metamorphosis

Of all of the blood sucking insects which attack mankind the mosquito is among the most pernicious you Mosquitoes are devided into two great tribes The Anophelines transmit malaria assumes this position in biting and the Culcines which transmits yellow fever, dengue and filarioses bites in this position The mosquito body is divided into three parts The head, thorax and abdomen the thorax bears three pairs of legs and a single pair of wing, the head bears the eyes, the feelers are antenna the palpae and the beak the abdomen bears no special structures except reproductive organs. In a female the antennae are covered with short hairs rising from the edge of each segment while in a male the antennae are conspicuously prompted with large hairs. The prominent antennae are the distinguishing features of a male. A mosquito bite primarily to obtain food. As a female settles down to a blood meal her beak appears to bend at the middle actually the beak consist of a giant protected sheath that bends. While a thin lenses enclosed within the sheath pierces the skin. A cross section of the beak shows that these lenses consists of six separate stylets which enclose between them two tubes, one for saliva and one for blood. A small amount of the insect saliva is injected into the blood to prevent coagulating of the blood which is then sucked up as food. The abdomen growth well perceptibly as the blood meal progresses. A male mosquito cannot bite or suck blood a newly emerged male may try blood sucktion without success, the beak of the male is not constructed to pierce human our animal skin. Male mosquitoes feed exclusively on vegetable juices the nectar of flowers the juice of the fruits. The females also feed of vegetable juices but blood form the major part of their diet Some mosquitos lays eggs on the surface of water, some near the water some mosquitoes like shaded water, others sunnly. Some requires fresh water others prefers soup. But all of them require water of some kind. Floodwater mosquitoes lay their eggs singly in mud. Near water or in other areas which later may be covered with water the eggs of floodwater mosquitoes can remain dormant some time for years until the conditions of warm and water are suitable for hatching floodwater mosquitoes living in regions having cold winters overwinter in the egg stage A section of mud taken from a site where flood water mosquitoes are known to breed in summer when immersed in water at room temperature will calls mosquito larvae to appear a few days later. most other mosquito over winter in the adult stage. Such hibernating adult can be found in hollow tree in colvers, under houses, proches, or in cellers these mosquitoes lay eggs fitted with two floats on the surface of the water or in large mass called eggboats. Except when overwintering mosquito eggs hatch into larvae soon after they are laid some times in less than a day. A mosquito larva after hatching is usually quite gray in color floating at the surface of the water, it inhales air through its breathing tube Soon, emerge some larger larvae in the second instar or period of the development in the sameway the larvae passes through the third and into the fourth and last instar. The larva has no legs or other organs of locomotion and moves by a series of jerks or winces. In some species, the body of the larvae is transparent and the heart action may be observed. As in all insects, a contraction waves begin posteriorly and advance anteriorly watch closely this pay overhead translation. The head and thoracic segments of the larvae aren't large sometimes twice as thin as the abdomen segment. The abdomen is divided into 9 segment, the first seven of which resemble each other closely in different level in species. On the eigth segments are the *** gills on the edge segment tubes through which the larva breathe most larvae hang head down with a breathing tube at the surface of the water. Anopheles larvae are horinzontaly when feeding on the surface of water. Examined closely the most parts are seemed to be in constant motion. The Anopheles larvae which can turn its head 180 degrees to facilitate feeding also stay at the water surface with a small brushes to bring the floating particles on which it feeds. When a larva is on the fourth instar, and appendage bud which is related to the growth of the legs and wings can be seen on the ventral side of the thorax from the transparent cuticle. in the second instar, theses buds while already differentiated are not yet well enough develop to be visible at this point of growth. The larvae now begins the change to the pupae form. Getting out of the body slightly, it begins to tears its cuticule usually beginning at the head, for a while the insect may rest, its new pupae head projecting from its larval body Right away with a few convulsive jerks, the larval cuticle complete with breeding tubes is passed off, and here is the pupae. In this stage no food is taken, all over body remains in water a pupae has its legs and thorax hatched into one mass, with no obvious organs except two black spots, which will later become eyes and two hard shape appendages at the top of the thorax, which serves as breathing tubes The abdomen terminates in two swimming paddles, which prepare the pupa through the water. As the pupae growth older, the wings become recognizable holded up against the wing, are the leggs of the adult. The pupae stage is short-lived, lasting usually only one to four days in warm water. When the adult is fully developped as in this pupae case, the pupae is less active, and tends to take a shinny appearence Skin pierce from the middle of the back. The adult rises up almost radically literally moving out from the pupil envelope the wings are first, finally the long legs are carefully extended to support the fully developed body in a few minutes the drying process is complete, the insect is now ready to fly. With this final transformation, it is now a familiar adult mosquito. The mosquito is an excellent exemple of an insect undergoing complete metamorphoses : the egg, the larvae, the pupae and the adult. Surely, the female of the species is more deadly than the male.