Lecture 20

Question 1

ectoparasite

Answer 1

an organism which spends much of its adult life in close assoc with the habitat created by the skin & its outgrowths of mammals & birds or with the host’s nest or roost, possessing obvious adaptations to its habitat and deriving its food from its host

Question 2

why is a cockroach not a parasite?

Answer 2

not in close assoc

Question 3

why is a mosquito not a parasite?

Answer 3

not in close assoc

Question 4

what are the 2 grps of ectoparasites in Canada not well studied?

Answer 4

lice & mites

Question 5

what are the characteristics of all lice? (7)

Answer 5

Ectoparasites of birds/mammals

Hemimetabolous

Wingless

Dorso-ventrally flattened – enables movement among feathers or hairs

Backward-directed setae – facilitates movement through feathers

Eggs cemented to hairs/feathers

3 juvenile instars

Question 6

what are the characteristics of sucking lice?

Answer 6

Sucking mouthparts

Tarsal claws (one/leg; some large) – OT

Blood-feeders only; mammals only

Question 7

what are the characteristics of chewing lice?

Answer 7

Chewing mouthparts

Tarsal claws (always small)
1 claw when parasitic of mammals – OT
2 claws when parasitic on birds – OT

Feed on hair/feathers &/or blood consumed

Question 8

Rhynchopthirina

Answer 8

parasites of elephants, rhinos & warthogs

Question 9

Laemobothrion

Answer 9

largest chewing lice

Question 10

Nosopon lucidum

Answer 10

smallest chewing lice

Question 11

where do lice attach?

Answer 11

thickest hairs of their host

Question 12

what adaptation do sucking lice from seals have?

Answer 12

hairs are modified into scales

Question 13

direct contact

Answer 13

one host is physically against another one

Question 14

what are the methods of dispersal in lice?

Answer 14

direct & indirect contact

Question 15

what are the 4 ways of direct contact in lice?

Answer 15

parent to offspring (vertical)

during roosting (horizontal)

during mating (horizontal)

allogrooming (horizontal)

Question 16

parent to offspring dispersal of lice is done in what animals? (2)

Answer 16

great grey owls, royal albatross

Question 17

roosting dispersal of lice is done in what animals?

Answer 17

roosting broadgulls, emperor penguins

Question 18

indirect transfer

Answer 18

hosts don’t come close to each other

Question 19

what are the ways of indirect contact in lice?

Answer 19

phoresy

fomites

Question 20

what is a method of human-assisted dispersal of lice?

Answer 20

fomites

Question 21

what does horizontal transfer of lice mean?

Answer 21

occurs outside the nest

Question 22

what is the method of vertical transfer of lice?

Answer 22

parent to offspring

Question 23

how do chewing lice latch onto their host?

Answer 23

latch on to hairs & feathers with exerted mouthparts

Question 24

how do sucking lice latch onto their host?

Answer 24

with tarsi since their mouthparts are not exerted

Question 25

why are birds an attractive host to lice?

Answer 25

have a variety of feather thicknesses

Question 26

why do lice lay eggs in hairs?

Answer 26

ensures the attachment of their eggs

Question 27

describe pelican lice

Answer 27

Males exist in pouches When teneral female emerges, the males latch on to the female Mate with female, release her Female leaves pouch & goes back to feathers to lay eggs Looks like the pouch is for mating

Question 28

what were the benefits of prof's study? (5)

Answer 28

Host diversity (275 spp.) Sample size Geographic distribution Total ectoparasite pop - good quantitative data No animals sacrificed

Question 29

what were the disadvantages of prof's study? (6)

Answer 29

Sample sizes Geographic distribution Sample bias – lice are free to feed on dead hosts Deficiencies in collection data Cross-contamination Spatial distribution lost