Life Cycle of the Mosquito (Culex Pipiens)

Classification
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Family: Culicidae
Genus: Culex
Species: pipiens

Mosquitoes are holometabolous insects. The complete life cycle of mosquitoes takes about 13–15 days to complete.

Egg
Anopheles lays eggs horizontally and singly on the water surface. Eggs are boat-shaped, having 2 lateral air floats, which help in floatation. In Culex, the eggs are laid in clusters on the water surface, forming rafts. The egg in Culex is cigar-shaped, without lateral air floats.

Larva
The eggs hatch after 2 to 3 days, and a small transparent larvae measuring about 1 mm emerges. The larvae of mosquitoes are popularly known as wriggles. Its body is divided into head, thorax, and abdomen. The head bears a pair of compound eyes, a pair of simple eyes, a pair of 2 jointed antennae, and the chewing mouthparts. The thorax is slightly broader than the head and bears 3 pairs of lateral tufts of hair. The abdomen is segmented into 9 parts. The larva contains long respiratory siphons. It undergoes 4 moults and 5 instars.

Pupa
Pupa, or tumblers, are motile. The head and thorax form the cephalothorax, which has a pair of trumpet-shaped breathing tubes. The body is commashaped. The abdomen consists of 9 segments, with palmate hair and caudal fins on the eighth segment for swimming. The pupa remains at the surface for about a day before the adult emerges. After 48 hours of the pupal stage, the pupal skin splits and the mosquito emerges as an adult.

Adult
The adult uses air pressure to break open the pupal case, and crawls to a protected area and rests while its external skeletal hardens, spreading its wings to dry. Males are smaller; mouthparts are not adapted for sucking. The abdomen is smaller. The female mosquitoes are bigger in size than the males. Their mouthparts are adapted for blood sucking, which is essential for the development of ovaries/eggs. The males feed on nectar from flowers. The thorax bears 3 pairs of legs, 1 on each segment, and a pair of wings on the mesothorax. Wings on the metathorax are modified to halters. Adult females live for a month and adult males for a week