Entomology

Mosquitoes Have worldwide distribution Have worldwide distribution Morphology: 4-10 mm in size. Head: carries a pair of eye, a pair of long antennae and a mouth. In female: the mouth parts are adapted for piercing and sucking of blood. In male: the mouth parts are not well developed, it feeds only plant juice.

Thorax: It is three segmented. It carries three pairs of legs and one pair of wings covered by scales. Abdomen: Slender and long, it is made up of eight segments. Life cycle: Female mosquitoes lay eggs on water, which hatch releasing larvae, which then converted to pupa, then within two days, adults are formed and fly out of the water. Adults eggs larva pupa adult Acquatic stages of mosquitoes (living in water): 1- larva 2- pupa

Mosquitoes The commonest mosquitoes are: 1- Anopheles: Spotted wings (dark and pale spots of scales). 2- Culex: Unspotted wings and unspotted legs. 3- Aedes: spotted legs

Medical importance of Mosquitoes: 1- They act as vectors for human diseases a- Anopheles: a- Anopheles: 1- Malaria: infective stage: sporozoites Mode of transmission: bite of female anopheles, by which it injects the sporozoites into blood of man. 2- Filaria: (ex. Wuchereria bancrofti) Infective stage: infective larvae Mode of infection: bite of female mosquito by which it deposits the infective larva on human skin and the larva enter through the wound bite

3- Arboviruses: Infective stage: virus Mode of transmission: bite of female mosquito injecting the virus with its saliva. B- Culex: 1- Arboviruses (similar to anopheles) 2- Filaria (similar to anopheles) C- Aedes: 1- Yellow fever: Infective stage: virus Mode of transmission: bite of female aedes mosquito

2- Dengue fever: Infective stage: virus Mode of transmission: bite of female aedes mosquito 3- Filaria: (similar to anopheles) 4- Bacterial diseases: Infective stage: Treponema Mode of transmission: bite of female aedes mosquito 2- Diseases produced by mosquitoes: All types of mosquitoes produce dermatitis at the site of bite.

Adult anopheles: (spotted wings) We have to differentiate between male and female. Differentiation occurs by the mouth part -Male: dense hair. Maxillary palps are as long as the proboscis, with clubbing. -Female: less hair. Maxillary palps are as long as the proboscis, but they are slender with no clubbing.

Adult culex: (unspotted wings nor legs) We have to differentiate between male and female. Differentiation occurs by the mouth part -Male: dense hair. Maxillary palps are as long as the proboscis, they are slender. -Female: less hair. Maxillary palps are shorter than the proboscis.

Larva of anopheles and culex: Larva consists of head, thoracic and abdominal segments. -Culex: The 8 th abdominal segment carries a respiratory siphon. -Anopheles: No respiratory siphon.

Control of mosquitoes 1- Protection of man from bites of mosquitoes by: 1- Protection of man from bites of mosquitoes by: -Sleeping under nets -Wearing protective clothes -Using repellents -Living away from water collections. 2- Destruction of mosquitoes by: -Physical methods: drainage of any water collection on filling with sand

Control of mosquitoes -Chemical methods: Application of substances in water that are toxic to the acquatic stages, as paris green and petroleum oils. -Biological methods: Application of living organisms in water to eat the larva. Ex. gambusia fish eats the larvae. 3- Control of adult mosquitoes: By spraying insecticides By spraying insecticides

Sand flies (phlebotomus) Females are blood suckers, while males feed on plant juices. Morphology: 1.5 – 2.5 mm in size, yellowish in colour. Head, thorax and abdomen. Hairy, the hairs cover the body, wings and legs. Has humped thorax, attached to it one pair of wings and 3 pairs of legs. Male has claspers on the posterior end.

Medical importance of Phlebotomus: 1- They act as vectors for human diseases 1- Leishmania: infective stage: promastigotes Mode of transmission: bite of phlebotomus. 2- Phlebotomus fever: Infective stage: virus Mode of transmission: bite of phlebotomus. 3- Oroya fever (bartonellosis): Infective stage: Bartonella Mode of transmission: bite of phlebotomus.

2- Diseases produced by phlebotomus: They produce dermatitis at the site of bite. Life cycle: Female phlebotomus lays eggs in cracks Adult ---- eggs larva ---- pupa adult

Control of sand fly: Sand flies have tendency to stay close to the ground and of short flight range. So, they are easily controlled. The control is by: 1- Insecticides 2- Filling of cracks. 3- Sleeping under nets 4- Application of repellants.

Musca (house fly) World wide in distribution. Morphology: Medium- sized flies, 6 – 9 mm in length. Head: contains 2 compound eyes and 3 simple eyes, 2 antennae and sucking mouth part. Thorax: carries 3 pairs of legs and one pair of wings. Abdomen: 4 segments. Life cycle: Female musca lays its eggs on garbages. Adult eggs ---- larva ---- pupa ---- adult

Medical importance of musca: –Medical transmission of organisms on legs and body hairs: 1- Parasitic diseases: Cyst of Entamoeba histolytica, cyst of Giardia, eggs of Ascaris. 2- Bacterial diseases: Typhoid, Cholera. 3- Viral diseases: Poliomyelitis, Hepatitis.

Control of musca: A- Control of adult flies: -Wire screening of houses -Fly net over the food -Insecticides. B- Control of breeding places: -Garbage should be properly disposed -Sanitary disposal of excreta -Health education.