MOSQUITO

· Mosquito is a two-winged insect (also housefly and fruit fly).

· The common genera of mosquito are:
A. Culex (body held parallel to the surface while sitting)
B. Aedes (= Stegomyia) (body held parallel to surface while sitting, with black and white striped body)
C. Anopheles (Body held at an angle to the surface, dark-spotted wing).

· Female mosquitoes are bloodsuckers of vertebrates while the male sucks the plant juice.
· Female mosquito is an ectoparasite (sanguivorous) and it is also an intermediate host for the pathogens like Plasmodium and Filaria.
· Plasmodium can be called a hyperparasite because its host mosquito is a parasite.
· Like other insects, the body of mosquitoes is divisible into the head, thorax, and abdomen.
· Head bears a pair of antennae, compound eyes, and mouthparts.
· In the adult mosquitoes, ocelli (simple eyes) are totally absent (in cockroaches and houseflies, ocelli are present).
· Thorax is three-segmented with only one pair of wings (mesothoracic). Metathoracic wings are modified into halteres which are balancing and sound-producing structures.
· Mosquito shows sexual dimorphism
Sex differentiation can be done on the basis of antennae and maxillary palps.
· Antenna of a male mosquito is plumose [more hairy or brushy and female is pilose (with few short hairs).
· Maxillary palp is as long as proboscis in both sexes but club-shaped in male Anopheles.
· Maxillary palp is three jointed, smaller than proboscis and clubbate in female Culex.

MOUTHPARTS

· Female mosquitoes are bloodsuckers. They have piercing and sucking mouthparts.
· Males feed on nectar and have only sucking mouthparts.
· Mouthparts found in both sexes are: Labrum plus epipharynx forming upper lip and labium and its two labellae form proboscis.


· Mouthparts of female:
(i) Hypopharynx (1) injection needle-like with central salivary duct running through it. Saliva contains anticoagulant.
(ii) Mandibles (2) needle-like with serrated broad saw-shaped.
(iii) Maxillae (2) needle-like with sharp blades at the tip.

The puncturing elements in the mouthparts of female mosquitoes are maxillae and mandibles.


· Mouthparts of male:
(i) Hypopharynx is less-developed, fused with labium.
(ii) Mandibles are totally absent.
(iii) Maxillae are reduced.
· Food channel is formed by labrum plus epipharynx and hypopharynx.


LIFE CYCLE

· Male and female mosquitoes copulate while in flight (as in honeybee).
· Fertilized eggs are laid on the stagnant water surfaces.



Life cycle of Anopheles Mosquito






Life cycle of Culex Mosquito



· Mosquito undergoes a complete metamorphosis.
· The larva of mosquito is also known as 'wriggler'.
· Wriggler is a free-swimming, active and aquatic larva performing wriggling movements.
· The body has a head, thorax (without legs), and abdomen (9-segmented).
· Head bears a pair of compound eyes, a pair of simple eyes (absent in adult mosquito), a pair of small antennae.
· Wriggler has a lifespan of 3-4 days.
· During this period it undergoes four moults to give rise to five instar larva.
· If all water reservoirs (ponds etc.) get dry, the chance of dissemination of malarial parasites is minimized as the larval stages of mosquito will die causing no survival of mosquitoes.
· Spraying of oil on stagnant water controls malaria because mosquito larvae can’t breathe and die.
· Fish that can be used in the biological control of mosquitoes is Gambusia.
· The pupa of mosquito is known as a tumbler.
· 5th instar larva changes into a pupa (non-feeding). It is comma-shaped.
· Pupa has cephalothorax and abdomen (9-segmented, ventrally flexed).
· It has a pair of respiratory trumpets.
· Tumbler has a life span of 2–7 days (in Musca 4–5 days).
· After completion of metamorphosis, it will transform into an adult called Imago.
· Female mosquito lives for a month or more and the male is about a week.
· Johnston's organ lies in the second segment of antennae. 
In the male mosquitoes, it helps to locate females by flight tone.


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