Fleas

Question 1

What is a parasite?

Answer 1

an organism that obtains nourishment and shelter on/in another organism, without usually causing death

Question 2

What is an ectoparasite?

Answer 2

A parasite that spends some or all of their lives parasitising and usually live on or burrow into the surface of the host’s skin

Question 3

Describe the anatomy and function of the exoskeleton/cuticle of fleas

Answer 3

Made of chitin
Protection
Site of muscle attachment
Limits respiration
Limits size of each growth stage

Question 4

Describe the respiratory system of fleas

Answer 4

Spiracles
Filters and oils at end of spiracles protect from dust and repel water

Question 6

What is hemimetabola?

Answer 6

Type of insecta life cycle
Partial metamorphism
Eggs -> nymphs -> adults
e.g., lice

Question 7

What ectoparasites come under the insecta class?

Answer 7

Lice
Flies
Fleas

Question 7

What is holometabola?

Answer 7

Type of insecta lifecycle
Full metamorphism
Eggs -> larvae -> pupae -> adult
e.g., flies, fleas

Question 7

What ectoparasites fall under the class arachnida?

Answer 7

Ticks, mites

Question 8

Describe the physical adaptations of fleas

Answer 8

Tube-like mouthparts to grip onto hair
Laterally flattened with hard exoskeleton
Wingless
Backwards pointing spines - can’t be pulled off host
Enlarged hind legs for jumping

Question 9

How do fleas cause disease?

Answer 9

Through:
irritation
allergy
blood loss/anaemia
spread of infections

Question 10

What are the most common fleas in the UK?

Answer 10

Question 11

What is the technical name for fleas?

Answer 11

Siphonaptera

Question 12

Label these fleas

Answer 12

Question 13

Label these fleas

Answer 13

Question 14

Describe the lifecycle of a flea

Answer 14

Eggs
- oval, pearl-like
- hatch in 1.5-6 days (depends of temp)

Larvae
- 3 stages of development (instars)
- negatively phototropic
- positively geotropic
- develop in 5-11 days

Pupae
- ~5mm long
- pupa covered in environmental debris
- 1 week to develop
- can stay in pupa for montha/years until appropriate stimuli detected

Adult

Question 15

What are the indirect effects of fleas?

Answer 15

Can act as a vector/host to pathogens e.g., myxotosis, bartonella
Can act as intermediate host for dog tapeworm

Question 16

Explain how fleas are controlled

Answer 16

Adulticides e.g., fipronil
Environmental control e.g., insect growth regulators
Mechanical removal

Question 17

Describe the ectoparasite ectoskeleton/cuticle

Answer 17

Made of chitin
- Polysaccharide (a bit like cellulose) and protein

Protection
- Crunchy on the outside

Site of muscle attachment

Limits size of each growth stage (further growth only possible through moulting, even in larvae where cuticle is soft)

Question 18

Describe how fleas act as an intermediate host for Dipylidium caninum (dog tapeworm)

Answer 18