aethropods 5

8/3/2019 Aethropods 5

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Phylum ArthropodaPhylum ArthropodaThe phylum Arthropoda is the largest phylum of the Animal Kingdom.The phylum Arthropoda is the largest phylum of the Animal Kingdom.

At least three quarters of a million species have been recorded; this isAt least three quarters of a million species have been recorded; this is

more than three times the number of all other animals speciesmore than three times the number of all other animals species

combined. The tremendous adaptive diversity of arthropods hascombined. The tremendous adaptive diversity of arthropods has

enabled them to survive in virtually every habitat they are perphas theenabled them to survive in virtually every habitat they are perphas the

most successful of all the invaders of the terrestrial environment.most successful of all the invaders of the terrestrial environment.

Arthropods have a wide range of feeding habits; they feed on solid Arthropods have a wide range of feeding habits; they feed on solid

food materials or juices, or on vertebrate blood. Many of them are freefood materials or juices, or on vertebrate blood. Many of them are free--

living and others live as pests and parasites on plants and otherliving and others live as pests and parasites on plants and otheranimals, or as predators. Most arthropods play an important role in theanimals, or as predators. Most arthropods play an important role in the

general economy of man, his crops, and his livestocks. The phylumgeneral economy of man, his crops, and his livestocks. The phylum

includes familiar forms as spiders, mites, scorpions, shrimps, crabs,includes familiar forms as spiders, mites, scorpions, shrimps, crabs,

insects, centipedes and millipedes.insects, centipedes and millipedes.


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Characteristics ofCharacteristics of

Phylum Arthropoda:Phylum Arthropoda:

11.. Arthropods are bilaterally symmetry (segmented), metameric and Arthropods are bilaterally symmetry (segmented), metameric and

triploblastic animals reflecting their annelidan ancestry, but mosttriploblastic animals reflecting their annelidan ancestry, but most

species exhibit some degree of reduction in metamerism as aspecies exhibit some degree of reduction in metamerism as a

consequence of loss, fusion and differentiation of segments.consequence of loss, fusion and differentiation of segments.

22.. The body is divided into segments which are not all alike but differ inThe body is divided into segments which are not all alike but differ in

formform andand structure. They are also usually grouped into three mainstructure. They are also usually grouped into three main

regions recognized as the head, thorax and abdomen.regions recognized as the head, thorax and abdomen.

33.. They have paired jointed appendages which are specialized in manyThey have paired jointed appendages which are specialized in many

ways, thus adapted to perform various functions (walking, swimming,ways, thus adapted to perform various functions (walking, swimming,

jumping).jumping).


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44.. The body is covered by a chitinous exoskeletonThe body is covered by a chitinous exoskeleton divided into platesdivided into plates

and cylinders, permitting movement, and is periodically shed,and cylinders, permitting movement, and is periodically shed,permitting growth.permitting growth.

55.. Muscles attached to the inside of the skeleton and theMuscles attached to the inside of the skeleton and the

skeltomuscular system functions as a lever system.skeltomuscular system functions as a lever system.

66.. All internal structures derived from invaginations of the body wall All internal structures derived from invaginations of the body wall

have a chitinous lining. The anterior and posterior parts of the gut,have a chitinous lining. The anterior and posterior parts of the gut,

called the foregut and hindgut, possess such a lining. The midgut,called the foregut and hindgut, possess such a lining. The midgut,

derived from endoderm, is more restricted then in most animalsderived from endoderm, is more restricted then in most animals..

77.. The blood vascular system is open, and the dorsal heart isThe blood vascular system is open, and the dorsal heart is

primitively tubular hemocoelamic body, organs bathed inprimitively tubular hemocoelamic body, organs bathed in

hemolymph.hemolymph.


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88.. The nervous system is like that of annelids. The sense organs areThe nervous system is like that of annelids. The sense organs are

highly developed and include simple or compound eyes, sensoryhighly developed and include simple or compound eyes, sensory

setae, auditory organs and statocysts.setae, auditory organs and statocysts.

99.. Complete digestive system with anterior appendages to from mouthComplete digestive system with anterior appendages to from mouth

parts.parts.

1010.. Excretion, aquatic through gills (ammonia) or green glandsExcretion, aquatic through gills (ammonia) or green glands

Malphigian tubules (uric acid).Malphigian tubules (uric acid).

1111.. Terrestrial forms respire by a system of branching air tubes knownTerrestrial forms respire by a system of branching air tubes known

as the tracheae, or by lung books (Arachnids). Aquatic formsas the tracheae, or by lung books (Arachnids). Aquatic forms

respire by gills and through the body surface.respire by gills and through the body surface.

1212.. Sexes are separate, and the young usually hatch from the eggs inSexes are separate, and the young usually hatch from the eggs in

an immature stage that undergoes a gradual change, calledan immature stage that undergoes a gradual change, called

metamorphosis, to become adult.metamorphosis, to become adult.


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Classification of Arthropoda:Classification of Arthropoda:

The phylum includes many classes, orders, and theThe phylum includes many classes, orders, and theother categories. However, we will concern with theother categories. However, we will concern with the

following:following:

Class: CrustaceaClass: Crustacea

Portunus (crab)Portunus (crab)PenaeusPenaeus (shrimp)(shrimp)


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Class: MyriapodaClass: Myriapoda

Millipede (Diplopoda)Millipede (Diplopoda)

Centipede (ChilopodaCentipede (Chilopoda))

ScolopendraScolopendra (centipede)(centipede)


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Class ArachnidaClass Arachnida TheridionTheridion (spider)(spider)

Class: ArachnidaClass: Arachnida


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MelicodesMelicodes (grasshopper)(grasshopper)

Class: InsectaClass: Insecta


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Distinguishable comparisons amongclassesof Aethropoda.

InsectaInsectaArachnidaArachnidaMyriapodaMyriapodaCrustaceaCrustaceaCharacterCharacter

Three,Three, Head,Head,Thorax,Thorax,AbdomenAbdomen..

Two,Two, ProsomaProsoma(Cephalothorax),(Cephalothorax),OpithosomaOpithosoma(Mesosoma,(Mesosoma, Metasoma)Metasoma)..

Two,Two, HeadHead andandTrunkTrunk..

Two,Two, CephalothoraxCephalothorax(Head(Head fusedfused withwiththorax),thorax), AbdomenAbdomen..

BodyBodyregionsregions

33 pairspairs of of legslegsattachedattached totothoraxthorax..

44 pairspairs ofof legslegs attachedattachedtoto cephalothoraxcephalothorax regionregion..

NoNo legleg atat opithosomaopithosoma..

OneOne pairpair of of legslegsperper eacheach bodybodysegmentsegment..

ManyMany legs,legs, 44 pairspairs of of

walking,walking, 77 pairspairs of of

swimmeretsswimmerets..

No. ofNo. oflegslegs

CompoundCompound eyes,eyes,11 pairpair of ofantennaeantennae..

SimpleSimple eyes,eyes, ocelliocelli.. Don'tDon'thavehave antennaeantennae..

SimpleSimple eyes,eyes,ocelliocelli andand 11 pairspairs

ofof antennaeantennae..

CompoundCompound eyes,eyes, 22pairspairs ofof antennaeantennae..

SenseSenseOrgansOrgans

AquaticAquatic formsforms::GillsGills.. LandLandformsforms:: TracheaTrachea..

AquaticAquatic formsforms:: GillsGills.. LandLandformsforms:: Trachea,Trachea, lunglungbooksbooks..

TracheaTrachea..AquaticAquatic formsforms:: GillsGills..

LandLand formsforms:: TracheaTrachea..RespiratoRespiratory organsry organs

MalpighianMalpighiantubulestubules..MalpighianMalpighian tubulestubules..

Malphigian

Malphigian

tubulestubulesGreenGreen glandsglands..ExcretionExcretion

MostlyMostlyterrestrial,terrestrial, SomeSomeaquaticaquatic

MostlyMostly terrestrial,terrestrial, SomeSomeaquaticaquatic..

TerrestrialTerrestrial..MostlyMostly aquatic,aquatic, fewfewterrestrialterrestrial..HabitatHabitat

Grasshopper,Grasshopper,ButterfliesButterflies..

Spider,Spider, Mites,Mites, TicksTicks..Scolopendra,Scolopendra,SympgylaSympgyla..

CryCry fish,fish, Crabs,Crabs,lsopodalsopoda..ExampleExample

Examples of each will be studied in detail in practical lessons.


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Economic Importance of PhylumEconomic Importance of Phylum

Arthropoda:Arthropoda:Phylum Arthropoda contain various members that affectPhylum Arthropoda contain various members that affect

man, animals and plants. Some aquatic forms related toman, animals and plants. Some aquatic forms related toclass. Crustacea used by man as food like shrimp andclass. Crustacea used by man as food like shrimp andlobsters. The land crustacean include members that play alobsters. The land crustacean include members that play a

role in decomposing plant and animal remnants. Sow bugrole in decomposing plant and animal remnants. Sow bug(wood lice) is the most familiar example of crustacean lives(wood lice) is the most familiar example of crustacean livesin land. Also, other members related to order Isopodain land. Also, other members related to order Isopodaburrow under ground feeding on roots of plant seedlingburrow under ground feeding on roots of plant seedlingcausing serious damage. Moreover, they could attack fruitscausing serious damage. Moreover, they could attack fruitsof strawberry, watermelon and sweet melon, scratching theof strawberry, watermelon and sweet melon, scratching theouter surface of the fruits helping the microorganisms toouter surface of the fruits helping the microorganisms toattack the fruit tissues. Likewise members of Myriapodaattack the fruit tissues. Likewise members of Myriapodadecompose plant materials to simple compounds availabledecompose plant materials to simple compounds availableto plant uptake.to plant uptake.


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Other species of Myriapoda prey smaller animals like

Other species of Myriapoda prey smaller animals like

earthworms, mollusks and insects. Thus, these animals ofearthworms, mollusks and insects. Thus, these animals of

Myriapoda maintain the natural balance. Moreover, thereMyriapoda maintain the natural balance. Moreover, there

are some species related to Centipedes and Millipedesare some species related to Centipedes and Millipedes

attack crops causing considerable loss in yield. As forattack crops causing considerable loss in yield. As for

class Arachnida, its members have relative importance toclass Arachnida, its members have relative importance to

man, animals and crops. For instance members ofman, animals and crops. For instance members of

Araneida (Spiders) are mostly predators feeding on Araneida (Spiders) are mostly predators feeding onanimals juices as they feed on sow bugs, scorpions, mites,animals juices as they feed on sow bugs, scorpions, mites,

insects and snails.insects and snails.


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Larger spiders can feed on small amphibian, reptiles,Larger spiders can feed on small amphibian, reptiles,

birds and mammals. Thus, spiders play a role in naturalbirds and mammals. Thus, spiders play a role in naturalbalance, that they can be used in biological control tobalance, that they can be used in biological control to

eliminate injurious pests. Members of order Scorpionida areeliminate injurious pests. Members of order Scorpionida are

also predators attack smaller animals like insects, spiders,also predators attack smaller animals like insects, spiders,

centipedes and millipedes. The larger species can feed oncentipedes and millipedes. The larger species can feed onmice and rats by killing the victims with poisons and thenmice and rats by killing the victims with poisons and then

sucking the animal juices. Scorpions may attack man bysucking the animal juices. Scorpions may attack man by

stinging him, and then, the secreted poison may causestinging him, and then, the secreted poison may cause

death. Mostly members of Pseudoscorpionida are soildeath. Mostly members of Pseudoscorpionida are soilinhabitants feed on decomposed material, but some ofinhabitants feed on decomposed material, but some of

which are predators on smaller animals.which are predators on smaller animals.


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Order Acarina contain mites ticks which include severalOrder Acarina contain mites ticks which include several

species bring important to agricultural production. Ticks arespecies bring important to agricultural production. Ticks areparasites on the domestic animals. Also, mites are parasiteparasites on the domestic animals. Also, mites are parasite

on domestic animals, man as well as the economic crops.on domestic animals, man as well as the economic crops.

Class Insecta includes members having economicClass Insecta includes members having economicimportance for man and his livestocks as well as for cropsimportance for man and his livestocks as well as for crops

production. Some insect species have medical importanceproduction. Some insect species have medical importance

to man and his domestic animals. Blood suckers may actto man and his domestic animals. Blood suckers may act

as vectors to many pathogens. Many other insect speciesas vectors to many pathogens. Many other insect species

act as dangerous pests on economic crops. Due to theact as dangerous pests on economic crops. Due to the

economic importance of mites and ticks, the followingeconomic importance of mites and ticks, the following

examples will be discussed in details.examples will be discussed in details.


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Ex.Ex. 11--Common Red Spider MitesCommon Red Spider Mites::

Several economic crops have been attacked by the phytophagusSeveral economic crops have been attacked by the phytophagusmite,mite, Tetranychus urticaeTetranychus urticae..

Symptoms of T. urticae:

A wide spread pest has attacked several economic crops, A wide spread pest has attacked several economic crops,

including field crops, vegetables, ornamentals and fruit trees.including field crops, vegetables, ornamentals and fruit trees.Symptoms appear as yellowish pale spots on the lower surface ofSymptoms appear as yellowish pale spots on the lower surface of

the infected leaves. Gradually, the spots change to dark yellowishthe infected leaves. Gradually, the spots change to dark yellowish

then transfer to reddish and finally to brownish spots. In highlythen transfer to reddish and finally to brownish spots. In highly

infected plants, the spots become larger and joining together toinfected plants, the spots become larger and joining together tocover most or entire the lower leaf surface. The upper surface ofcover most or entire the lower leaf surface. The upper surface of

the infected leaf has purple colour which then turns to dark brown.the infected leaf has purple colour which then turns to dark brown.

In advanced case, the leaves die and fall down; and fruits becomeIn advanced case, the leaves die and fall down; and fruits become

scabby.scabby.


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Life cycle:Life cycle:The female deposits eggs singly around leaf veins specially on theThe female deposits eggs singly around leaf veins specially on the

lower surface, as well as on buds. When the egg hatches, a larva withlower surface, as well as on buds. When the egg hatches, a larva with

three pairs of legs emerges and starts to feed on leaf tissues juice. Then,three pairs of legs emerges and starts to feed on leaf tissues juice. Then,

the larva becomes quite before molting to a protonymph which has fourthe larva becomes quite before molting to a protonymph which has four

pairs of legs, and starts to feed for a while after which it becomes quitepairs of legs, and starts to feed for a while after which it becomes quite

and molts to deutonymph. It then feeds, becomes quite and molts toand molts to deutonymph. It then feeds, becomes quite and molts to

mature female or male. Mating occurs and females deposit eggs tomature female or male. Mating occurs and females deposit eggs to

repeat the life cycle. The life cycle lastsrepeat the life cycle. The life cycle lasts 88 days in summer anddays in summer and 4040 day inday in

winter. A number ofwinter. A number of 2727 generations per a year is found under thegenerations per a year is found under the

Egyptian circumstances. One female can lay a number ofEgyptian circumstances. One female can lay a number of 100100 eggseggs

during its life span.during its life span.


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Developmental stages of the life cycle ofDevelopmental stages of the life cycle ofTetranychusTetranychus urticaeurticae

EggEgghatchhatch

Larva deposit eggLarva deposit egg ((33, pairs of legs), pairs of legs)

MM

ProtonymphProtonymph(Mature)(Mature)(Mating) Male Female(Mating) Male Female

((44, pairs of legs), pairs of legs)

M MM M

DeutouymphDeutouymph

((88 days in summer)days in summer)

((4040 day in winter)day in winter)


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Treatment and Prevention:Treatment and Prevention:11.. Elimination of weeds which act as hosts for mites during preElimination of weeds which act as hosts for mites during pre--cropping periods.cropping periods.

22.. Using healthy plant materials (seedingsUsing healthy plant materials (seedings--cuttingscuttings-- corms bulbscorms bulbsetc).etc).

33.. Treatments with acaricides to reduce the mites populations.Treatments with acaricides to reduce the mites populations.

Ex.Ex.22 TheThe Soft and Hard Ticks of DomesticSoft and Hard Ticks of DomesticAnimals:Animals:

The ticks are classed in two families, Argasidae or "Soft ticks", and Ixodidae

"Hard ticks" which differ considerably both in their structure and life cycle.

Structurally the Argasidae are distinguished by having the body covered by a

leathery cuticle marked by numerous tubercles or granulations, and sometimes

small circular discs, also but no plates or shields. The Ixodidae, on the other hand

have a dorsal shield or scutum that almost completely covers the back in males,

but only the anterior portion of it in females. Another character distinguishing

these two families is the ventral position of the mouth parts in the Argasidae and

their anterior position in the Ixodidae, where they fit into a groove or camerostome

at the anterior end of the body. The females of both families when unfed are flat,

but after their gluttonous meals they become grotesquely engorged


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and resemble beans or nuts. Also, several nymphal stages exist in of

ticks, while in hard ticks, there is only one nymphal stage. Soft ticks are

quick feeders as they attached to the host for several days and feed only

once . After feeding the adult female lays a large mass of eggs and dies.

Adult soft ticks, on the other hand, lay eggs after each blood meal.

AA-- The Fowl Tick,The Fowl Tick, Argas PersicusArgas Persicus::

Widely distributed; though it infests several hosts, e.g. birds, specially

fowls and small mammals. It related to Fam. Argasidae.


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Symptoms of Argas Persicus:Symptoms of Argas Persicus:

The parasitized animals become weak due to sucking of large

amounts of bloods which leads to appearance of anemic disorders.

The presence of ticks in large number causes irritation and

annoyance. More serous than the painful wound made by ticks is a

peculiar paralyzing effect of tick bits, known as tick paralysis. Also,

the tick may act as a transmitter of the bacterial disease,

Spirochetosis caused by Borrelia onserina, whichaffects egg andmeat production in fowls and other birds.


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::A. persicusA. persicusLife Cycle ofLife Cycle of

The adult females lay their eggs in batches at intervals of

weeks or months. The eggs require from 2 to 3 weeks to

develop. Eggs deposited in the fall do not hatch unit the

following spring. Newly hatched ticks are called larvae, and

are recognizable by having only six legs. The larvae feed on

host blood for a long period before molting to nymphs which

remain attached to the host for 1-2 hours getting their blood

meal. Then, the nymphs move away to rest and molt for thesecond time to second stage- nymphs. They feed on host

blood and after a while molt to adults. Egg laying begins a

week or more after mating and feeding.


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Treatment and Prevention:Treatment and Prevention:

11-- Cleanliness of poultry houses.Cleanliness of poultry houses.

22-- Spraying of floors and walls with chemicals may eliminate ticks for aSpraying of floors and walls with chemicals may eliminate ticks for a

long time.long time.

33-- Dusting with chlorinated hydrocarbons or other chemicals is effective.Dusting with chlorinated hydrocarbons or other chemicals is effective.

44-- Spraying poultry houses, roosts, and litter with special chemical.Spraying poultry houses, roosts, and litter with special chemical.

B- The Hard Tick, Hyalomma aegyptiaca:

This tick infests cattle, sheep, camel, horse, cat, and fox. It usually

exist in places plenty in grass. It related to Fam. Ixodidae..


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:aegyptiacaHyalommaSymptoms of

The wounds made by the tick bites may cause inflammation and damageto the host tissues. The tick salivary secretion, which passes into the

wound during he bite, may cause tick paralysis to the host. It may

transmit pathogenic viruses to the infested animals.

Life Cycle ofLife Cycle of H. aegyptiacaH. aegyptiaca::The adult females take a single enormous meal, after which they drop

off the host to soil and lay their eggs at once. After a period, the newly

hatched ticks known as larvae which have six legs each, remain waiting

until a suitable host passes within reach. Often they crawl up on a bladeof grass or a twig to reach to the host. They feed for only a few days,

becoming distended with blood and then distended with


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blood and then dropping to the ground again. After a while

they shed their skin and emerge as eight-legged but sexaully

immature ticks known as nymphs. The nymphs are

distinguishable from females by absence of the genital

aperture. They climb upon bushes or weeds waiting for a

host, unless they stay starved in the absence of the host.They get their meals from the host, and drop to the ground

to digest the meal, transform, and molt to sexual mature

adults then, they climb up to host for mating, copulating,

and the males usually die shortly after copulation. The

females get down. Laying a large mass of eggs and die.


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Treatment and Prevention:Treatment and Prevention:

Cleanliness of the domestic animal's pens.

Spraying houses, barns and/or dipping infested animals

in pens with special acaricides.

Elimination of weeds and grasses, or using chemical

control by dusting or spraying the pastures or grasses.


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Mite (left) and Tick (right)Mite (left) and Tick (right)

pedipalps&

chelicerae

cephalothorax

abdomen


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T. UrticaeT. Urticae

Mating HatchingMating Hatching

EggsEggs LarvaeLarvae((33 pairs of legs)pairs of legs)

AdultAdult

++ FeedFeedQuiteQuiteMoltMolt

Feed, Quite Feed, QuiteFeed, Quite Feed, QuiteDeutonymph ProtonymphDeutonymph Protonymph

Molt Molt (Molt Molt ( 44 pairs of legs)pairs of legs)

Singly on the leaflower surface or

buds

L.C. 8 days in summer, 40 days in winter.27 generations.


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Soft TickSoft Tick

MatingMating 22--33 weeks (developing)weeks (developing)

EggsEggs LarvaeLarvaeFallFall SpringSpring ((66 legs)legs)

AdultAdult

++ FeedFeed

MoltMolt

Feed,Feed, Feed (Feed (11--22 hrs.),hrs.),

22ndnd stage nymph Nymphstage nymph Nymph

MoltMolt Rest, MoltRest, Molt

In

batches

A. persicus


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Hard TickHard Tick

+ Big meal+ Big meal

Climb to Eggs Larvae

the host for (in soil) (6 legs)

Mating Large mass

AdultFeed,

++ Molt

Soil or Digest FeedPlants

molt Nymph

(6 legs)

H. aegyptiaca


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Distinguishable comparisons between the softand hard ticks.

Hard ticksSoft ticksCharacter Related to Fam. Ixodidae Related to Fam. ArgasidaeTaxonomicTaxonomic

groupgroup

Body has a dorsal shield orscutum which completelycovers the back in males, butonly the anterior portion offemales.

Body covered by a leatherycuticle marked by tuberclesor granulations, no plates orshields.

MorphologicalMorphologicalvariationsvariations

Mouth parts located in ananterior position.

Mouth parts located in aventral position

Have one numphal stage. Slow feeders; long-feeding

ticks; adults feed only once.

Adult lays a large mass of

eggs and then dies.

Have several nymphalstages

Quick feeders; nymphs andadults feed frequently.

Adult lays eggs after eachblood meal.

BiologicalBiologicalvariationsvariations


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2011/20122011/2012

aethropods 5

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