人体寄生虫学课件：insect

1、 InsectaCharacteristics of Class Insecta1. Body: small, fragile, 3-6mm long 3 body segments: head, thorax (chest), abdomen (stomach area).2. 3 pair of legs, 1 pair to each of the 3 thoracic segments. 1 pair of antennae.3. Wings- usually two pairs of wings, although some have one pair of wings, or no

2、ne.4. Compound eyes: 1 pairs of eyes, with facetsInsectHeadThoraxAbdomenA pair of complex eyesA pair of antennaeMouth partsProthoraxMesothoraxMetathoraxThe thorax bears three pairs of legs and two pairs of wings11 segments. The ecto-reproduction organ also locate in the abdomenInsect mouthparts(口器)C

3、hewing type (beetles, cockroaches) Piercing-sucking type (mosquitoes, bugs)Lapping and sponging type (flies)Cutting-sponging mouthparts (tabanid fly)Metamorphosis （变态）process：egglarvaladultMetamorphosis During insect development from egg to adult, there are widely differences in morphology,physiolog

4、y and living habits.Complete Metamorphosis ：egg-larval-pupa-adultIncomplete Metamorphosis ：egg- nymph(larval)-adultComplete metamorphosisEgglarvaePupa (chrysalis) AdultThe larvae and adult have difference in morphology and life habit; There is pupa stage in their life cycle.Such as mosquitoes, fly,

5、sandfly, and flea.Incomplete metamorphosisEggLarvae (nymph)AdultThe larvae is similar in morphology and life habit with the adult, but the sexual organ still undeveloped; There is no pupa stage in their life cycle.Such as louce, bug, and cockroach.ClassificationDiptera (双翅目)蝇,蚊,白蛉Siphonaptera (蚤目)-

6、致痒蚤Anoplura (虱目)- 人虱Blattaria (蜚蠊目)蟑螂Coleoptera (鞘翅目)甲虫Hemiptera (半翅目)锥蝽,臭虫Mosquitoes （蚊)Mosquito belong to Class insecta, Order diptera, Family CulicidaeThere are more than 3350 species of mosquitoes belong to 38 generaAnophelesCulexAedesMorphologyAdult brownish or grayish or blackish in color,1.61

7、2.6mm in lengthThe body is divided into head, thorax and abdomen. 1.1 HeadSubglobosewith an pair of antennae（触角）compound eyes an pair of palpi（触须）one long proboscis（喙）Mouthparts(Proboscis)：piercing and sucking type Anopheles Culex Aedes The palpus is same as proboscis in long female: palpus shorter

8、than proboscis female: palpus shorter than proboscis male: palpus longer than proboscis male: palpus is the same of proboscis compound eyesMosquito head showing 2 large compound eyes. The antennae have been removed. The circular bodies in which the antenna is embedded are visible. 300.piercing and s

9、ucking mouthparts Proboscis（喙）喙含有1个上内唇、1对上颚、1对下颚和1个舌组成，它们包藏在鞘状的下唇内。雄蚊上、下颚退化，不能叮刺吸血，只以植物液汁为食。1.2 Thorax divided into pro-,meso-,and metathorax; with a pair of wings; 3 pairs of legs; the leg is long and thin; the scales form the whitea pair of halteres平衡棒. wing veins and wing borders 2nd and 4th and

10、5th are forked; 1st、3rd and 6th are unbranched，presence of scales (鳞片) on the body纵脉2、4、5各分两支，1、3、6不分支。1.3 Abdomencomposed of 11 segments，28 are visible The last 3 modified into external genital organs.雄蚊生殖器官2. Egg2.1 Anopheles eggThe eggs have distinct lateral floats.Tiny , larva (4 stages) ( 7 day

11、s) pupa(2-3 days ) adult.10-14 days totaleggadultheadrestinglarvapupa Life cycle stageHiding 、resting places and HibernationThey stay in dark, poorly ventilated and humid places.Culex pipiens pallens suck blood and rest in room;Anopheles sinensis suck blood in room and rest outside; Aedes albopictus

12、 rest outside.The majority of mosquitoes hibernate through winter in their adult stge, some in larval or egg stage.Feeding Only female mosquitoes suck blood. Female must have a blood meal before they deposit mature eggs. Male mosquitoes do not bite, they feed on plant juice, drops and sugar. MatingT

13、hey usually mass mate during wilight, late in the afternoon, or early in the morning. Female mosquitoes lay multiple batches of eggs and require a blood meal for every batch they lay. 40 eggs/a female mosquito. 海 报活 动：空中舞会时 间：黄昏地 点：房檐下组织者：雄蚊目 的：交配与产卵花前月下交配与产卵：蚊在交配前有群舞现象Anopheles lay eggs in relative

14、ly fresh water, as rice fields, streams,ponds,etc.Culex lay eggs in polluted water,stagnant and dirty ponds.Aedes lay eggs in small water bodies and containers-jars,tree holes,hoof prints and even in dry empty tins. -Breeding placeAnopheles breeding placeAnoheles lay eggs in relatively fresh water,

15、as rice fields, streams, ponds, etc.Paddy fieldSlowly flow waterJungle or forest fieldCulex breeding placeCulex lay eggs in polluted water, stagnant and dirty ponds.Aedes breeding placeLife span、Range of flight Life span: Males, 1-3 weeks. Females, much longer, hibernating females may live as long a

16、s 5 months or more.Range of flight: 500 meters long and 300 meters high.Mosquitoes and diseases 1.Annoyance pest (bite, suck blood) A mosquito bite may induce local dermatitis or even systematic reaction in sensitive persons.2.Transmite disease(1) filariasis(2) Malaria(3) Japanese encephalitis B (4)

17、 Dengue fever(5) yellow feverChild with hypersensitivity to mosquito bites.Control1. Individual protection by site selection for homes, nets or screens, chemical repellents, etc. 2. Elimination of breeding places. 3. Insecticides. 4. Biological control; Genetic control and protection of mosquitoes n

18、atural enemies (bat, dragon fly, swallow, Gambusia fish, etc.)虱(Louse)Lice are permanent ectoparasites of humans, mammals and birds, cosmopolitan in distribution.Two species parasitize man:Pediculus humanus (体虱）and Pthirus pubis （阴虱）.Pediculus humanus include PhCapitis and PhCorporis.虱(louse)I Morph

19、ologyAdult1.1 PhCorporis （体虱）small, dorsoventrally flattend, wingless, light gray 3 pairs of legs, provided with hook-like claws. 4.4mm， Smaller than ；Female terminal end is in “W” shape; male terminal end is in “V” shape1.2 PhCapitis （体虱）Smaller than body louse, dark gray.头虱（成虱和幼虱）Lice on the head2

20、 Pthirus pubis （阴虱）Light gray, crab-like Smaller and shorter than bodylouse1.52.0mm Smaller than 2. Pthirus pubis 耻阴虱Pthirus pubisThe back of Pthirus pubisThe abodomen of Pthirus pubis二、Life cycle and Habit Live on human body. Incomplete Metamorphosis.have egg, nymph and adult 3 stages Egg7 daysnymp

21、h (3 stages:9 14 days)adult 2.1 Egg: nit Elongate oval in shape0.80.3mmwhite in colorcommonly called a nit glued to fiber or haira lid on one end. 2.2 NymphThe nymph looks like an adult but is smaller in size and sexual organs are not developed，molts 3 times become an adult Feeding: Both nymphs and

22、adults feed on human blood.Most active at 22-37. They are discouraged by hot and cold temperatures. They will leave the host when it has a high body temperature or is dead.The transmission of lice chiefly from man to man; blankets and clothing are secondary.III louse and diseaseBiting：Produces itchi

23、ng. Nymph、male and female adults are blood suckers. They are obligatory host-specific. They do not suck blood from other animals. They always defecate when they are sucking blood. Pediculosis2.Transmitting desease:（1）Epidemic typhus(流行性斑疹伤寒): Organisms from louse feces or crushed louse body may be transmitted through skin abrasions. （2）Trench fever (战壕热): a rickettsial disease.（3）Relapsing fever (回归热): Spirochetes exist in louse body cavity. Control1. Hygienic mesuresboth personal and public. Take a bath, wash head and change clothes frequently. 2. Delousing