MOSQUITO
Phylum: Arthropoda
Class: Insecta
There are four common groups of mosquitoes. They are Aedes, Anopheles, Culex, and Culiseta.
Structure of Mosquito
It has slender body with three segments: head, thorax and abdomen.
The head has compound eyes, a pair of long, segmented antennae and an elongated, projecting "stinger-like" proboscis used for feeding.
The proboscis is adapted for piercing and sucking blood. The visible part of the proboscis is the labium, which enclosed six mouthparts. The labium bends back into a bow and the tip remains in contact with the skin when the mosquito begins to bite.
Three pairs of legs and a pair of wings are attached to the thorax.
The second pair of wings is reduced to tiny protrusions or tiny stumps called halteres. These vibrate rapidly and help the insect to obtain balance
Feeding in Mosquito
Only the female has the piercing and sucking mouthparts. The male feeds on plant juices such as nectar.
The female is adapted for piercing the skin of host and sucking the blood as ectoparasites.
It injects saliva into the body of the host, containing chemical that prevents the blood from clotting. The pathogens inhabit in the saliva glands of mosquito. They find the way into the host through the stream of saliva.
Life Cycle of Mosquito
Mosquitoes go through complete metamorphosis in life cycle: egg, larva, pupa, and adult.
Adult females lay their eggs in stagnant water; near the water edges. In some species, the eggs are stuck together in rafts whiles other lay their eggs separately. The eggs hatch into larvae within 48 hours.
The larva has a developed head with mouth brushes used for feeding, a large thorax with no legs, and a segmented abdomen.
It breathes through a tube or siphon or through spiracles located on abdomen.
Larvae swim in the water by jerky or wriggling movements of their entire bodies, giving them the common name "wigglers" or "wrigglers".
Larvae go through four stages, or instars, after which they metamorphose into pupae. The mosquito pupa is comma-shaped. The head and thorax are merged into a cephalothorax, with the abdomen curving around underneath.
The pupa eventually breaks open at the water surface and the adult wriggles out. The wings expand and the adult flies off.
Economic Importance of Mosquito
1. Viral diseases, such as yellow fever and dengue fever, transmitted mostly by Aedes.
2. Malaria caused by various species of Plasmodium is carried by Anopheles mosquitoes.
3. Lymphatic filariasis (the main cause of elephantiasis) which can be spread by a wide variety of mosquito species.
4. The larva serves as food to aquatic organisms.
How to Control Mosquito
1. Removing stagnant water and filling or drainage of breeding places.
3. Trapping, and/or using insecticides to kill larvae or adults.
4. Spraying lakes and ponds with oil films to reduce surface tension causing the lava and pupa to suffocate and die.
5. Insecticide impregnated mosquito nets are particularly effective because they kill those insects that attack humans.
6. Insect repellents can be applied on skin to give protection against mosquito bites.
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