1. More than 3000 species of mosquitoes have been described on a world-wide basis. Scientists group species by genus on the basis of the physical characteristics they share. These species are divided among 28 differentThese species are divided among 28 different genera, one of them is Culex genus, that has approximately 1216 species. commonly has in Asia and Australia. Culex known as vectors of the pathogens causing human diseases.

2. Kingdom: Animalia Phylum: Arthropoda Class: Insecta Order: Diptera Family: Culicidae Species: Culex spp. 3. Culex body: small, fragile, 3-6mm long. Piercing-sucking mouthpart, Proboscis and 6 needles. External genitalia. Adult abdomen, thorax, legs, Halters, and one pair wings are uniformly covered with brown scales.wings are uniformly covered with brown scales. Adult is terrestrial, but Larva and Pupa are Aquatic. Distinguishing of sexes: 1. Female : Plumose antenna, Male : Pilose antenna. 2. Only female Culex bites and drinks animals blood, Male does not bite and drink blood. Both sexes feed on flower nectar for water and sugars. They have been known to fly up to two miles 4. EggAdult Eggs Adult LarvaPupa Larva Pupa 5. (Common house mosquito) 6. Female Male Female Mouth part 7. CulexCulex antennaantenna Female : Plumose antenna Male: Pilose antenna 8. Culex lay their eggs on the surface of water. lay their eggs one at a time usually at night. may lay a raft of eggs every third night during its life span. It is sticking them together to form a raft of from 200-300 eggs. A raft of eggs looks like a speck of soot floating on the water and is littleonly about (6mm) long andthe water and is littleonly about (6mm) long and (3mm) wide. The eggs hatch in 1418 hours. Tiny Culex larvae emerge from the eggs within 1-4 days. Culex egg is brown, long and cylindrical. 9. Larva :The larva (larvae - plural) called: wigglers live in the water and come to the surface to breathe.They shed their skin four times growing larger after each molting. Most larvae have long, narrow siphon tubes for breathing and hang from the water surface.the water surface. Larval instars (4). In 59 days, larvae are fully developed. Aquatic, Filter feeders. eats algae and small organisms which live in the water. Respiration. 10. Some times the Culex larvae become fishes and other insects food. 11. Pupa: commonly called ;tumblers;, The pupal stage is a resting, non-feeding stage. Like a;,; divided into cephalothorax and abdomen. It moves actively but takes no more food.It moves actively but takes no more food. This is the time the Culex mosquito turns into an adult. When development is complete, the pupal skin splits and the Culex emerges as an adult. It takes about 2-3 days before the adult is fully developed. Respiration. 12. Culex Pupa 13. The pupal skin splits and the Culex emerges as an adult 14. Pupa 15. Adult:The newly emerged adult rests on the surface of the water for a short time to allow itself to dry and all its parts to harden. Also, the wings have to spread out and dry properly before it can fly. After 35 days of emergence, adult flies are ready Culex adult After 35 days of emergence, adult flies are ready to mate. Feeding . 16. Surface water, the wings spread out and Dry Ready for flying Completed adult Culex 17. Culex mosquitoes are night biters, and they commonly rest indoors before and after biting. Both male and female mosquitoes feed on plant nectar, fruit juices and liquids that ooze from plants as their main source of energy, by burning it as fuel for flight and is replenished on a daily basic and help in the pollination of many flowers.pollination of many flowers. Blood is reserved for imbibing less frequently and mostly for egg production, because female Culex lay multiple hatches of eggs, thus require a blood meal as a source of protein for every hatch they lay. Hibernation Culex, like all insects, are cold blooded creatures. As a result, they are incapable of regulating body heat and their temperature is essentially the same as their surroundings. 18. Culex usually live only a few weeks during the warm summer months. Those females which emerge in late summer search for sheltered areas where they ;hibernate; until spring. Warm weather brings her out in search of water on which to lay her eggs. in spite of ; some species survive bad conditions. Culex are generally distributed in urban Culex are generally distributed in urban environments around the world, and towns with poor or inadequate drainage and sanitation support large populations, but they are not common or absent in extreme northern parts of temperate zones. Most species breed in ground pools, puddles, and agricultural fields, breeds in waters polluted with organic debris, such as household refuse and excreta. 19. 1. Annoyance pest: A mosquito bite may induce local dermatitis or even systematic reaction in sensitive persons. 2. Arboviruses diseases : such as: A-West Nile (WN) virus belongs to the Japanese encephalitis virus complex, preferentially transmitted by Culex species, with wild birds.Culex species, with wild birds. B- Encephalitis viruses (of different types with different vector species of Culex): Japanese encephalitis (JE) virus. Venezuelan Equine Encephalitis (VEE) virus, U.S. 20. Scientists have found Culex mosquitoes may fly as far as 2 miles (3.22 kilometers),This lets them carry encephalitis to whole new areas . Every year, there are cases of encephalitis reported around the world, Most are in Asia and Australia. 3. Parasitic diseases: filariasis:Two worms, Wuchereria bancrofti and Brugia malayi,are responsible for over a hundred million active cases of filariasis worldwide.The worms live inmillion active cases of filariasis worldwide.The worms live in the lymphatic system Cx. uinquefasciatus its vector. 4. In 1924 M. Hertig and S. B. Wolbach observed bacteria in the cells of a mosquito (Culex pipiens). Hertig formally described them in 1936 as Wolbachia pipientis in honor of his collaborator in the earlier work. Wolbachia, an intracellular bacterium discovered first infecting the ovaries of Culex pipiens mosquitoes. 21. A mosquito can "smell" its human blood dinner from a distance of up to 50 kilometers (30 miles) away. A female mosquito begins locating prey by detecting carbon dioxide, which is emitted by animals when they exhale and through their skin. The mosquito uses an antenna-like structure called a maxillary pulp to detect carbon dioxide from as far as (50 m) away. Atpulp to detect carbon dioxide from as far as (50 m) away. At closer distances, it uses a feathery antenna to identify certain chemicals, and its nose is perforated with many tiny holes that the odors in the air can penetrate. After the mosquito has found a concentration of carbon dioxide being emitted by a person, the mosquito's sensory receptors tell it whether the combination of chemicals and odors being emitted by that person make him or her suitable prey. 22. Scientists are still investigating the complexities involved with mosquito host acceptance and rejection. Most mosquitoes are attracted to the odor of carbon dioxide (C02). All humans exhale C02 with every breath. Yet this fact hardly helps explain why some people are "bitten" more than others. Very large people and pregnant women generally breathe Why are some people more attractive to mosquitoes than others? Very large people and pregnant women generally breathe out more carbon dioxide, so they tend to be bitten more often. Although it was once believed that blood types were an important factor in varying attraction rates, this theory has been discredited. There are over 400 such "magnetic compounds". It appears that some compounds come from within the body and some from without. 23. Research suggests that, in addition to carbon dioxide, some of the substances that people produce and that attract mosquitoes are sweat, lactic acid, uric acid and a chemical called octenol. Lactic acid is emitted through the skin, especially during exercise. Uric acid is a product of the body metabolizing certain proteins, and most of it ismetabolizing certain proteins, and most of it is excreted in urine, but excess uric acid can build up under the skin. Octenol is present in a person's sweat and breath. Some people produce greater quantities of these substances, so mosquitoes bite some people more than others. 24. People who exercise outdoors produce more lactic acid, sweat more and breathe more heavily, so they also tend to suffer more mosquito bites. Many perfumes and deodorants that people to mask their natural body odors also are believed to be attractive to Mosquitoes. Gender does not now seem to be the all-importantGender does not now seem to be the all-important factor in mosquito "bite" susceptibility. In most cases, only the mosquito knows why one person is more attractive than another. Although till correctly only mosquito now why some people most attract than others! 25. Robinson, William H. (2005). Urban insects and arachnids. Cambridge University press, USA. 17- 160-163-166 PP. Resh, Vincent H. and Carde, Ring T. (2003). Encyclopedia of INSECTS. (USA). Academic press, Elsevier Science. 53-333-600-696-744-746-747-1192 pp. Gullan, P.J. and Cranston, P.S. (2005). The Insect: An outline of Entomology.3ed edition. Blackwell publishing Ltd. 137-243-385-388 pp. Markle, Sandra. (2008). Insect World Mosquitoes. Minneapolis,USA. 10-32-33-36-PP. Gillot, Cedric.(2005). Entomology. 3rd ed. Springer, Dordrecht.The Netherlands.250-737 pp. Karthikeyan,V. ; Sivakumar ,K.; Gokuldass, Aishwarya and Mohanasundaram,s. (2012). 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