Week 2 - Fleas - COMPLETE ****

Question 1

Define Parasite

Answer 1

an organism that obtains nourishment and shelter in or on another organism

Question 2

Define Ectoparasite

Answer 2

a organism that spends some or all of their lives parasitising and usually live on or burrow into the surface of the hosts skin

Question 3

How does the Binomial system work to name an organism?

Answer 3

the first part of the name is the genus
the second part of the name is the species

Question 4

Anatomy: State the 3 main structural parts of an Insect (flea)

Answer 4

head
thorax
abdomen

Question 5

Anatomy: What is the exoskeleton made from?
- What is its main function?
- What does the exoskeleton limit and how? 2

Answer 5

a polysaccharide called chitin

it is hard to provide protection

it limits the absolute size of the organism because the exoskeleton is the site of internal muscle attachment
so their body would collapse in on itself if the muscles get any bigger

Question 6

Anatomy: How do insects grow?

Answer 6

they moult their exoskeleton and must grow before the new exoskeleton hardens

Question 7

Anatomy: How do they obtain oxygen?
- What are the other functions of this structure and how does it do it? 2

Answer 7

through spiracles in the exoskeleton

a filter at the opening keeps dust out
oils repel water

Question 8

Anatomy: Digestive System
- How do fleas and mosquitos eat?
- How do flies eat?

Answer 8

they have spikily mouthparts to puncture the hosts skin

they have spongey mouthparts and secrete saliva to digest food and then suck it up

Question 9

State the names of the 2 different insect life cycles

Answer 9

holometabola and hemimetabola

Question 10

Life Cycle: Which insects have holometabola life cycles?
- Which have Hemimetabola life cycles?

Answer 10

fleas and flies

lice

Question 11

Life cycle: Describe the holometabola life cycle 4

Answer 11

eggs
larval stages
pupa
adult

Question 12

Life cycle: Describe the Hemimetabola life cycle 3

Answer 12

egg
nymph stages
adult

Question 13

State the name for fleas

Answer 13

siphonaptera

Question 14

State the physical adaptations for a Flea 5

Answer 14

tube-like mouthparts
laterally flattened with hard exoskeleton
wingless
backwards pointing spines and bristles for attachment to host
enlarged hindlimbs for lumping

Question 15

Fleas: What do Adult males and female eat and why?
- How do they cause disease in the host? 4

Answer 15

blood because they are obligate blood sucking parasites

irritation
allergy
blood loss
spread of infections

Question 16

Name: Dog flea

Answer 16

ctenocephalides canis

Question 17

Name: Cat flea

Answer 17

ctenocephalides felis

Question 18

Name: Hen flea

Answer 18

ceratophyllus gallinae

Question 19

Name: Rabbit flea

Answer 19

spilopsyllus cuniculi

Question 20

Flea Lifecycle: How long can the eggs take to hatch?
- How many larval stages of development are there?
- How long does it take to go through all stages of larval development?
- What is the pupa/cocoon made from?
- How long will it remain in the cocoon once fully developed?

Answer 20

1.5-6 days depending on temperature

3

5-11 days

environmental debris

until it senses the appropriate stimuli

Question 21

Direct Effects: Why can a severe infestation of young or old animals be dangerous? 2

Answer 21

because the adult female cat flea can suck 13.6 micro litres blood per day
so a severe infestation can lead to anaemia

Question 22

Direct Affects: How can fleas cause irritation?
- What clinical signs would you see?

Answer 22

some substances in flea saliva act as allergens and can cause a severe allergic response

inflammation
pruritus

Question 23

Direct effects: Flea Allergic Dermatitis
- What is FAD?
- Which animals have the greatest reaction?
- Which animals will have the smallest reaction?

Answer 23

a common hypersensitivity reaction in cats and dogs

sensitised animals who are intermittently exposed to fleas

sensitised animals who are constantly exposed to fleas

Question 24

Indirect effects: How can fleas have indirect effects on a host?
- Give 3 examples and information about them

Answer 24

by acting as a vector or host for a range of pathogens

myxomatosis in rabbits caused by a poxvirus

cat scratch disease caused by bartonella henselae

feline infectious anaemia caused by mycoplasma haemofelis

Question 25

Indirect effects: Cat dog and human fleas can act as intermediate hosts for a specific tapeworm, what is it?

Answer 25

dipylidum caninum which is the dog tapeworm

Question 26

Indirect effects: Explain how fleas can infect hosts with the dog tapeworm 5

Answer 26

tapeworm eggs pass out in the faeces of the vertebrate host
the faeces are consumed by flea larvae
the tapeworm eggs hatch and the tapeworm develops within the fleas body cavity
the tapeworm larvae form an infective cysticercoid in the adult flea
the adult flea is consumed by the vertebrate host during grooming

Question 27

Control: What is the most effective non-chemical method for controlling fleas?
- what does this involve?

Answer 27

mechanical removal

removing flea eggs, larvae and organic debris by washing blankets, rugs, pet carrier and vacuuming pet sleeping areas

Question 28

Control: Give 3 examples of adulticide chemicals and explain how each works
- Give 2 examples of environmental chemicals

Answer 28

organophosphates - they overstimulate nicotinic synapses killing and repelling fleas
pyrethroids - they depolarise neurone via sodium channels killing and repelling fleas
fipronil - they interfere with GABA neurotransmission killing but not repelling fleas

organophosphates
pyrethroids

Question 29

Control: Give examples of products containing these chemical substances? 5

Answer 29

shampoos
sprays
collars
spot-ons
oral medication

Question 30

Control: Name 2 examples of insect growth regulators
- How does the first one work?
- Why might this be better for the environment?

Answer 30

lufenuron
methoprene

it interferes with chitin synthesis so strops the development of larvae in eggs and their ability to moult later on

it is stored in body fat and taken up by the adult fleas so does not go into the environment