GENERAL PROPERTIES GENERAL PROPERTIES OF ARTHROPODSOF ARTHROPODS

Phylum Arthropoda (jointed  feet) (jointed  feet) 

Doç.Dr.Hrisi BAHARDoç.Dr.Hrisi BAHAR

The arthropods areThe arthropods are ●● The most successful

phylum of animals, both in diversity of distribution and in numbers of species and individuals.

●● They have adapted successfully to life in water, on land and in the air.

●● They can survive great extremes of temperature, toxicity, acidity and salinity

ArthropodaArthropoda

ArthropodaArthropoda

●● About 80% of all known animal species belong to the Arthropoda

●● About 800,000 species have been described.

Characteristics of ArthropodaCharacteristics of Arthropoda

● ● MetamerismMetamerism- - body is segmented.

● ● ExoskeletonExoskeleton- - body covered with a

hard external skeleton.

● ● Bilateral SymmetryBilateral Symmetry-- body can be divided into two identical halves.

Characteristics of ArthropodaCharacteristics of Arthropoda

Jointed AppendagesJointed Appendages-- each segment may have one pair of appendages, such as:

●● legs

●● wings

●● mouthparts

Characteristics of ArthropodaCharacteristics of Arthropoda

●● Open Circulatory SystemOpen Circulatory System-- blood washes over organs and is not entirely closed by blood vessels. Our system is a closed one

●● Ventral Nerve CordVentral Nerve Cord-- one nerve cord, similar to our spinal column

Some of the arthropods are Some of the arthropods are ectoparasite.ectoparasite.

EctoparasiteEctoparasite: : arthropod living outside arthropod living outside the human bodythe human body

Some Common EctoparasitesSome Common Ectoparasites

●● Common bedbugsCommon bedbugs ((Cimex lectulariusCimex lectularius))

●● Human fleasHuman fleas ((Pulex irritansPulex irritans

Classes of Medical ImportanceClasses of Medical Importance

Subphylum CRUSTACEAE   Two Class are medically

important

●● Class ArachnidaArachnida   

●● Class InsectaInsecta

Class AracnidaClass Aracnida--------------------------------------------------------------------------------------------------------------------

MetastigmataMesostigmata Prostigmata

Astigmata

TicksFamily Ixodidae

Ixodes Dermacentor

Rhipicephalus, Haemaphysalis Family Argasidae

Argas, Ornithodoros

MitesDermanyssus Rnithonyssus

MitesCheyletiella,

Neotrombicula

MitesSarcoptes, Notoedres,

Psoroptes,Tyrophagus, Tyroglyphus, Glyciphagus,

Dermatophagoides

Class insectaClass insecta

D i p t e r a

Nematosera(mosquitoes, black flies)

Brachisera (flies)

Anoplura

(Lice)

CinsCins

Pediculus Pediculus

PhthirusPhthirus

Heteroptera (Bugs)

CinsCins

Cimex Cimex

OeciacusOeciacus

Triatoma Triatoma

RhodniusRhodnius

PanstrongylusPanstrongylus

CinsCinsAnophelesAnopheles CulexCulexAedes SimuliumPhlebotomusPhlebotomusLutzomyia

CinsCins

Musca, Glossina,

Calliphora,Calliphora,

Cochliomyia,Cordylobia,

Lucilia, SarcophagaLucilia, Sarcophaga

Wohlfahrtia,Gasterophilus

Hypoderma,Cuterebra

Siphonaptera

(Fleas) CinsCins Pulex Pulex Ctenocephalides Ceratophyllus Archaeopsylla Xenopsylla Tunga

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Class insectaClass insecta

●● The insects are the

most numerous anddiverse of all thegroups of arthropods.There are morespecies of insectsthan species in all theother classes of animalscombined.

Class insectaClass insecta●● Insects differ fromother arthropods inhaving three pairs oflegs. In size, insectsrange from less than 1mm to 20 cm in length,the majority beingless than 2.5 cmlong.  

Characteristics of Insecta

1-1- 3 body segments-  head, thorax ,

abdomen (stomach area).

2- One pair of antennae

3- Tracheal Respiratory System- composed of tubes, with holes (spiracles) through the body that admit air.

●● So, they do not have lungs at all..

Characteristics of Insecta

4-4- Wings- usually two pairs of wings, although some have one pair of wings, or none. No other class of arthropods has wings

5-5- 3 pair of legs, 1pair to each of the 3 thoracic segments. Compound eyes, with facets

Order Diptera (Flies)Order Diptera (Flies)

TThe larvae of flieshe larvae of flies..

Flies are common in the warmer months, Flies are common in the warmer months, and love dead, stinky, and rotting materialand love dead, stinky, and rotting material.. They lay eggs, and the eggs develop intoThey lay eggs, and the eggs develop into larvaelarvae (maggot) (maggot) that need to eat. They that need to eat. They appear quite fast (8-12 hours), and will eat appear quite fast (8-12 hours), and will eat away tissue if the conditions are presentaway tissue if the conditions are present

MyasisMyasis

Disease that results from the

infestation of tissues or

cavities of the body by

larvae(maggots) of flies

AnophelesAnopheles

●● Anopheles is a genus of mosquito mosquito (Culicidae).(Culicidae).

●● There are approximately 460 recognised species: while over 100 can transmit human malaria, only 30-40 commonly transmit parasites of the genus PlasmodiumPlasmodium that cause malaria which affects humans in endemic areas.

●● Anopheles gambiaeAnopheles gambiae is one of the best known, because of its predominant role in the transmission of the deadly species – –Plasmodium falciparumPlasmodium falciparum..

● Some species of Anopheles also can serve as the vectors for Filariidae Wuchereria bancroftiWuchereria bancrofti

●● Mosquitoes in other genera ((Aedes,CulexAedes,Culex) ) can also serve as vectors of disease agents.

Anopheles Anopheles gambiaegambiae

CulexCulex

Adults of the Cx. PipiensCx. Pipienscomplexcomplex are light brownmosquitoes that lackdistinctive markings onthe proboscis and legs,and are not readilyseparated from otherCulex (Culex) mosquitoes.Adult females of the complexare usually identified by thepresence of distinctive, basal,pale abdominal bands.

PhlebotomusPhlebotomus ((sand fliessand flies))

The female sand fly carries the Leishmania protozoa from infected animals after feeding, thus transmitting the disease, while the male feeds on plant nectar.

Phlebotomus species are also vector for

phlebotomus feverphlebotomus fever,, an arbovirusarbovirus  caused by Toscana virus.

Adults Adults are small are small sizedsized about 1.5-3 about 1.5-3 mm, yellowishmm, yellowish

in colour within colour with

conspicuous black conspicuous black eyes,eyes,hairy bodyhairy body, , wings andwings and legs. legs.

Anoplura (Lice)

•Pediculus ● Pediculus humanus capitis

● Pediculus humanus corporis

•Phthirus● Phthirus pubis

Lice

MorphologyMorphology

●● Wingless insects.Wingless insects.●● Permanent Permanent

ectoparasite.ectoparasite.●● Host specific Host specific

parasites,each lice parasites,each lice species is found on species is found on only a single only a single species of host.species of host.

Pediculus humanus

Pediculus humanus capitis(head louse) localization and sites of oviposition Hair on the head, rarely on beard hairs or hairy sites

onupper body.

● Pediculus humanus corporis(body louse) localization and sites of ovipositionStitching, seams, and folds in clothes, especially whereit is in direct contact with the body.

Phthirus pubis (crab louse)Phthirus pubis (crab louse)

localization and sites of localization and sites of ovipositionoviposition

Hair of pubic area, more rarely in theHair of pubic area, more rarely in the

abdominal and axillar regions, beard,abdominal and axillar regions, beard,

eyebrows, and eyelashes.eyebrows, and eyelashes.

Order HeteropteraOrder Heteroptera (Bugs)(Bugs)

CimexCimexCimex lectulariusCimex lectularius

● They are about 3–4mm long● Dorsoventrally flattened bodies ● Greatly reduced wings ● A bloodsucking proboscis that can be folded back ventrally

Siphonaptera -FleasSiphonaptera -Fleas Pulex Pulex

Pulex irritansPulex irritans (Pulex)(Pulex)

• This flea is about 2–5mm long, ● Laterally flattened,● Wingless ● Have three pairs of legs, the hindmost of which are highly adapted for jumping.

Fleas are competent vectors for numerous microbial pathogens of

medical and veterinary importance

●● Ctenocephalides felis (Cat flea)Vector of

-Cat scratch disease (Bartonella species) -Spotted fever (Rickettsia felis)

-Plague (Yersinia pestis)

●● Xenopsilla Cheopis(Rat flea)Vector of

-Plague (Yersinia pestis)

●● Pulex irritans(human flea)Vector of

-Plague (Yersinia pestis)

Class ArachnidaClass ArachnidaTicks (Ixodida)Ticks (Ixodida)

●They are blood-sucking, opportunistic parasites that can attach to the skin of

a variety of vertebrate hosts..

● They have no segmentation and are dorso-ventrally flat with four pairs of legs

Ixodes ricinusIxodes ricinus

● Vector of the causative agents of Lyme borreliosis and Tickborne encephalitis

● Human tick bites in central Europe are in most cases caused by

I. ricinus and only occasionally by other tick species.

Tick biteTick bite

DISEASES FOR WHICH DISEASES FOR WHICH HARD TICKS ARE CARRIERSHARD TICKS ARE CARRIERS

BACTERIAL DISEASES BACTERIAL DISEASES 

** ** Rocky Mountain Spotted FeverRocky Mountain Spotted Fever

The causativeThe causative agentagent,,Ricketsia rickettsiiRicketsia rickettsii, ,

**** Tularemia Tularemia

The causative agentThe causative agent ,Francisella Francisella tularensistularensis

**** Q FeverQ Fever

The causative agent, The causative agent, Coxiella burnetiiCoxiella burnetii

DISEASES FOR WHICH DISEASES FOR WHICH HARD TICKS ARE CARRIERSHARD TICKS ARE CARRIERS

BACTERIAL DISEASESBACTERIAL DISEASES

****Human erlichiosisHuman erlichiosis

The causativeThe causative agentagent, , bacteria of the bacteria of the Ehrlichia Ehrlichia family. family.

****Lyme DıseaseLyme Dısease

The causativeThe causative agent agent Borrelia burgdorferi (USA)(USA)

Borrelia garinii or Borrelia afzelii ( In Europe ) 

DISEASES FOR WHICH DISEASES FOR WHICH HARD TICKS ARE CARRIERSHARD TICKS ARE CARRIERS

VIRAL DISEASESVIRAL DISEASES

**** Crimean-Congo Hemorrhagic Fever Crimean-Congo Hemorrhagic Fever

The causativeThe causative agent agent Nairovirus.Nairovirus.

**** Tıck -Born Encephalitis Tıck -Born EncephalitisThe causativeThe causative agent,agent,Tick-borne Tick-borne encephalitis virusencephalitis virus

MitesMites

Sarcoptes scabieiCausative agent of scabies

Scabies mite (Sarcoptes scabei) is the cause of scabies and is distributed worldwide. Epidemics of the disease may occur for long periods but mites may be common at all times in very poor communities with inadequate washing facilities.

Sarcoptes scabiei

• Transmission is by close contact (sexual partners, family,members, school children, healthcare staff) from person to person,

• Indirect transmission on clothes (underclothes), bed linens is not a primary route, but should be considered as a factor in control measures.

• Without a host, mites usually die off within a few days. Mite infections can also be acquired from animals to which humans have close skin contact.