Mosquitoes

1. Mosquitoes AmalAlmuhanna 2012

2. Introduction • Mosquitoes are small insects with piercing-sucking mouthparts. • Scaly wings. • Female mosquitoes suck blood • The males cannot suck blood but both sexes feed on nectar of various plants. • In some species of mosquito, the females feed on humans, and are therefore vectors for a number of infectious diseases affecting millions of people per year.

3. Mosquito classification • Kingdom:Animalia • Phylum: Arthropod • Class: Insecta • Order :Diptera • Family:Culicidae • Common Genus : Anopheles, Aedes, Culex

4. Mosquito morphology

5. Mosquito morphology • Body is small, fragile, 3-6mm long. • A slightly shorter spread of its narrow wings. • Its body, like that of other insects, consists of head, thorax, and abdomen. • The round head has a long proboscis (tubular mouth part) and antennae.

6. Mosquito morphology • In the male, long hairs on the antennae give these appendages a feathery appearance. • Hairs on the antennae of the female are shorter. • The mosquito's slender legs are attached to the triangular thorax. • The abdomen is long and narrow

7. Male vs. female

8. Distinguishing of sexes • Antenna: plumose in male, pilose in female • Mouthparts: piercing and sucking type. • Proboscis and 6 needles. • palp • Feeding • External genitalia

9. Male vs. female

10. Mouth Parts • Mosquitoes have mouthparts which are adapted for piercing the skin of plants and animals. • They typically feed on nectar and plant juices.

11. Mouth Parts • Piercing and sucking mouth-parts is that suited for piercing the tissues of plants and animals and sucking up their sap or blood. • The labium forms a long, cylindrical, 3-segmented

12. Mouth Parts • The maxillae, each has 2 grooves on its inner surface. When they fit together, two tubes are formed between them. • The labrum is small and situated over the base of the proboscis. • The labium bears 2-terminal sensory labella. • The maxillary palpsare well developed ( in male 5-segmened and in female 3-segmented).

13. Wings • Single pair of membranous wings. • The other (hind pair) is modified into small knobbed sensory structures known as halteres.

14. Legs

17. Mosquito life cycle • Mosquitoes are aquatic in their early stages. • Mosquitoes go through four stages in their life cycle: egg, larva, pupa, and adult or imago. • The first three stages are aquatic. • Adult females lay their eggs in water. • 5–14 days, depending on the species and the ambient temperature; eggs hatch to become larvae, then pupae. • The adultmosquito emerges from the pupa as it floats at the water surface.

18. Medicalimportance • Flower pollination. • In some species of mosquito, the females feed on humans, and are therefore vectors for a number of infectious diseases affecting millions of people per year.

19. Now, we will study three genera with medical importance: • Aedes • Culex • Anopheles Aedes Culex Anopheles

20. Description Aedesadult • Aedes species are typical small mosquitoes. • They usually have black and white stripe markings on their body and legs. • Laid singly.

21. Aedeseggs • Initially white eggs turn a shiny black color a few minutes after being laid. • The egg shell has a mosaic pattern. • Egg are laid on a damp substrates just beyond the water line. • It can withstand desiccation (they can be dry but viable for many months).

22. Aedeslarva • Larvaehang head down from the surface of the water with their posterior breathing tube (siphon) extended above the surface for air. • There is only one pair of sub-ventral tufts of hairs. • There are three pair of setae on the ventral brush. • Larvae have length siphon. • Aedes larvae hang down from the water surface at an angle.

23. Aedespupa • The pupa is located on the surface of the water where it breathes through a pair of air tubes or trumpets. • This stage of the mosquito is commonly referred to as a "tumbler" because its form is larval.

24. Life cycle of Aedes

25. Life cycle of Aedes • Under optimal conditions, the egg of an Aedes mosquito can hatch into a larva in less than a day. • The larva then takes about four days to develop in a pupa, from which an adult mosquito will emerge after two days. • Three days after the mosquito has bitten a person and taken in blood, it will lay eggs, and the cycle begins again.

26. Medical importance of Aedes • The name comes from the Greek aēdēs meaning "unpleasant" or "odious", • So called because of the diseases this type of mosquito transmits, including dengue fever and yellow fever. In Polynesia, the species Aedespolynesiensisis responsible for the transmission of human lymphatic filariasis

27. 2- CulexMosquito • 3 famous culex species • C. pipiens • C. quinquefasciatus • C. tarsalis

28. 2- Culex Mosquito tarsalis Culex pipiens quinquefasciatus

29. Description Culex adult • Morphologically has the three body parts common to insects: head, thorax, and abdomen. • As a fly, it has one pair of wings. • All types of mosquitoes must have water to complete their life cycles. • Culexmosquitoes prefer small bodies of still water full of organic matter, such as tin scans, bird baths or rain barrel

30. Culex egg • Culex lays their eggs on the surface of fresh or stagnant water. • Mosquitoes prefer water sheltered from the wind by grass and weeds. • Culexegg is brown, long and cylindrical. • It may lay 300 eggs up-right on the water surface. • Culesxeggs are placed together to form an egg raft. • They are adhered to each other due to surface forces.

31. Culex egg Culexmosquito laying eggs.

32. Culexlarva • It has long, narrow siphon. - There are more than one pair of sub-ventral tufts of hairs on the siphon, non of them near its base

33. Culex larva

34. CulexPupa • A Culex pupa floats on top of the water for one to four days while it transforms into an adult mosquito. • The pupal phase is a non-feeding, resting stage.

35. CulexLife Cycle

36. Medical importance of culex 1. Annoyance pest : A mosquito bite may induce local dermatitis or even systematic reaction in sensitive persons. 2. Disease Carrier: Often a carrier of diseases, such as Filariasis, encephalitis, yellow fever, dengue fever, dog heartworm, West Nile virus, and many others. The females, who drink blood, can carry disease from one animal to another as they feed

37. AnophelesMosquito • Some species • Anopheles acanthotorynus • Anopheles albimanus • Anopheles albitarsis

38. Description Anopheles adult The adult females can live up to a month (or more in captivity) but most probably do not live more than 1-2 weeks in nature

39. Anopheles egg • Eggs are laid singly directly on water and are unique in having floats on either side. • Eggs are not resistant to drying and hatch within 2-3 days, although hatching may take up to 2-3 weeks in colder climates

40. Anopheles larvae • Anopheles larvae do not have a siphon and they lay parallel to the water surface. • The larva feed on micro-organisms and organic matter in the water. • On the fourth molt the larva changes into a pupa.

41. Anopheles pupae • As with the larvae, pupae must come to the surface frequently to breathe, which they do through a pair of respiratory trumpets on the cephalothorax. • The pupa is comma-shaped. • Pupae do not feed during this stage. • The pupa is less active than larvae

42. Anopheles life cycle

43. Medical importance of Anopheles • Malariaparasites are transmitted from one person to another by the female anopheline mosquito. • There are about 380 species of anopheline mosquito, but only 60 or so are able to transmit the parasite.

44. Summary (comparison) 1- Adult Aedes Culex Anopheles

45. 2- Eggs (3 strategies) • Singly on water surface • Anopheles • Singly in a pile, on moist substrates • Aedes • Form of a raft, on water surface • Culex Culex Anopheles Aedes

47. 3-Larval Stage – Growth Stage Anopheles

48. 4- Pupa Aedes Culex Anopheles Anopheline Culicine

49. Mosquito Pupa and Larvae

50. Anopheles Pupa and Larvae