W9&10 Phylum Arthropoda. Class Insecta. Flashcards
Class Insecta characteristics
body= head, thorax, + abodmen; 3 pairs of walking legs. pair of lrg compound eyes pair of antennae on the head; 2 pairs of wings in thoracic segments
what is Ametabolous development
Hatching eggs produce miniature copies of adults which increase size and shed exoskeleton Ecdysis. NO metamorphosis
what is Hemimetabolous development
Newly hatched are similar to adult but smaller in size +lack wings.sexually immature
incomplete metamorphosis HAS NYMPH STAGE
what is Holometabolous development
Newly hatched= completely different from adults . larval forms live in diff habitats. Larval stage= complete it stops feeding and builds cocoon around itself
HAS PUPA STAGE
Lava undergoes metamorphosis of organs fully formed adult.
Class Insecta Digestive system
closed. 3 part: foregut, midgut, hindgut
Complex digestive tract.
glands producing digestive enzymes+ anticoagulants.
mouthparts, related to their feeding habits.
Class Insecta circulation
open.
hemolymph confined to vessels. throughout rest of body it flows freely through body cavity. (hemocoel)
dorsal vessel acts as heart. it pumps hemolymph through the sinuses of the hemocoel.
DO NOT CARRY O2
Class Insecta respiration
tracheal system. air enters through spiracles. aquatic has gills
body muscles involved
Class Insecta excretion
Malpighian tubules remove nitrogenous waste from hemolymph. they work w/ hind gut
Class Insecta nervous
ganglia+ ventral double spinal cord
dorsal brain= linked to ventral nerve cord (paired ganglia)
CNS- most ganglia- brain+SC
peripheral nerve system: sensory neurons, sense organs-eye, sensitive to sound, sensitive to chemical
Class Insecta Reproduction
2 sexes, fertilization= internal
male locates female through chemicals (pheromones).
females store sperm in a special receptacle in abdomens
females mate only once and rely on sperm stored during that mating for the rest of their lives.
what are Pediculus humanus known as?
what are the types, habitat
head louse- doesn’t transmit infections
inhabits head w/ hair
body louse- transmits typhus
found in clothes+ underwear
Pediculus humans morphology
- female= 4mm, lrg eggs seen in abdomen, post end=bifurcated
- male= 3mm, copulatory organ reach post end= rounded
- body:covered by yellow/ brown chitinous exoskeleton
6 legs that end w/ curved chitinous claws- attach to hair
they are doors-ventrally flattened+ NO wings
EGG= ‘nits’: Females lay 3-4 eggs per day.
To attach an egg, the adult female secretes a glue from her reproductive organ.
egg = oval-shaped, 0.8mm
Pediculus humanus Transmission
direct contact w/ infected person, sharing louse-infected clothes
Pediculus humanus causes
transmitted diseases
pediculosis- severe itching, redness
Louse-borne Typhus = rickettsial disease .caused by “Rickettsia prowažeki”
it inhabits louse digestive
tract.
Relapsing fever caused by “Borrelia recurrentis” . It inhabits the louse hemolymph.
Pediculus humanus life cycle
nits= headlice egg
1) nits laid by adult female near scalp.
2) eggs hatch + release nymph. they mature after 3 molts+ become adults(6 legs)
3) they feed on blood several times to survive. w/o blood they die
3 NYMPH STAGE
What is Phthirius pubis known as?
crap louse or pubic louse-
doesn’t transmit diseases
Phthirius pubis morphology
2mm
body= round, is an obligate ectoparasite.
dorsoventrally flattened
6 legs w/ claws for clinging to hairs of host. back legs= thicker.front legs =equipped w/ large claws.
Phthirius pubis habitat
in pubic hair. in areas w/ coarse (thick) hair
Phthirius pubis cause
severe itching. DOES NOT TRANSIT DISEASES
Phthirius pubis transmission
from person to person via sexual contact.
They cannot jump, and feed
exclusively on blood.
Phthirius pubis life cycle
1) female eggs lays on hair shaft (30 eggs)
2) eggs hatch–> nymph (small version of adult) they most 3 times–> adult
require blood, w/o blood they die
3 NYMPH STAGES
what is Cimex lectularius known as
what are they? hosts?
common beg bug
blood feeding parasites of humans, chickens, bats and
domesticated animals.
Cimex lectularius morphology
body= dorsoventrally flattened covered by red- brownish chitinous exoskeleton ovoid w/ reduced wings.
mouth parts adapted for piercing + sucking. they inject saliva w/ antocoagulants+ painkillers
pair of antennae, pair of compound eyes.
male has present shaped copulatory organ
Cimex lectularius reproduction
sexual dimorphism.
mate by traumatic insemination. male pierces female abdomen+ injects sperm into female abdominal cavity. they reach ovaries= fertilisation
Cimex lectularius eggs
female lays 200 eggs, eggs laid on rough surface+ coasted w/ transparent coat =adheres them to substrate
Cimex lectularius life cycle
cimex takes blood meals, females lay eggs. eggs hatch–> nymph which take blood meals + molts into next stage.
5 NYMPHAL STAGE (blood meal between each stage)
–> adult
adult takes blood meal, mating occurs (traumatic insemination)
Cimex lectularius cause
carries
severe itching, skin rash
causes inflammation due to allergic components in saliva
carriers of leprosy, kin leishmaniasis, Q-fever
what is Pulex irritans known as
Human flea- bloodsucking ectoparasites of mammals and birds
Pulex irritans morphology
Small insect covered flattened body w/ yellow/brown Chitinous exoskeleton
no wings
posterior pair of legs elongated allowing insect to jump for escape and getting onto host
mouthparts adapted for piercing skin and sucking blood
LARVAE: worm like, feed of undigested blood in feces of adults
Pulex irritans as vector
plague
(agent: Yersinia pestsis), murine typhus (agent: Rickettsia typhi)
flea-borne spotted rickettsiosis (agent: Rickettsia felis).
intermediate host of Dipilidium caninum
Pulex irritans life cycle
eggs–> larvae–> pupae–> adults
eggs shed by female. eggs hatch–> larva+ feed on organic debris
larvae–> pupae=cocoons
adults hatch from pupae+ seek warm- blooded host= human
Genus Culex and genus Anopheles
Genus Culex = non malarial mosquito
Genus Anopheles= malaria mosquitos
only female feed on blood, male has feathery antenna
Genus Culex and genus Anopheles morphology
egg, larvae, pupae, adults
4-10mm
- egg:
C= light colour, laid vertically on water surface in groups,
A= bright, laid singly, they lay horizontally on water surface
- larvae:
C=has air tube at post end, so hangs at an Angle to water surface
A=no air tubes, lay parallel to water surface
- pupae:
C= abdomen less bent
A= abdomen more bent, have short air tube in ant part
- adults:
C= no spots on wings, at rest body lies parallel to surface
A= 4-5 sports on wings, st rest body is inclined at angle of 45 to surface
Genus Culex and genus Anopheles vector and transmitted diseases
Culex:
yellow fever (liver disease, yellow skin), denga, encephalitis (arboviruses), tularemia.
transmits filarial parasite
Anopheles:
transmits malarial parasite (plasmodium)
def host=Plasmodium species;
Genus Culex and genus Anopheles life cycle
egg–> larva(4)–> pupae–> adult
female lays eggs on water eggs, hatch into larva which swims, feeds -shed 4 LARVAL STAGES + grows into pupae
which comes to surface to breathe. pupae–> adult emerges.
adult has eyes, antenna, palps, + mouth part/proboscis
what is Phlebotomus papatasii known as
sand fly
Phlebotomus papatasii morphology
Chitin hair covered body
long legs
nocturnal, black eyes, hairy body when standing hold wings above body
female is bloodsucking.
Phlebotomus papatasii as vector
female carries the Leishmania protozoa transmitting the disease,
host + vector of leishmania Donovan- causes sandfly fever, kala-azar, leishmaniasis
vector of phlebovirus causing pappateci fever in human
Phlebotomus papatasii vs mosquito
Phlebotomus papatasii doesn’t require aquatic enviro to complete life-cycle
females lay eggs in soil or anyplace with decaying organic matter.
Phlebotomus papatasii life cycle
egg–> larva–> pupae–> adult
1) Female lays egg in damp dark places
2) eggs hatch– > larva which feed on organic matter 4 LARVAL STAGES–> Pupae found in cracks in walls then develops–> adult
