Fleas

Question 1

• What is the gross anatomy of a flea?

Answer 1

Three body parts (head, thorax, abdomen) and three pairs of legs

Question 2

• What is the purpose of the exoskeleton?

Answer 2

Protection, site of muscle attachment, limits absolute size, limits size of each growth stage

Question 3

• What is the function of the sensory hairs in spiracles?

Answer 3

Monitor external conditions and can trigger spiracle closing when necessary

Question 4

• What is the lifecycle of the flea?

Answer 4

Egg -> larvae-> pupae -> adult

Question 5

• What is the difference between hemimetabola and holometabola?

Answer 5

Hemimetabola – semi body change (Phthiraptera – lice)

Holometabola – complete body change (Diptera – flies, Siphonaptera – fleas)

Question 6

• Define the term ectoparasites

Answer 6

Ectoparasites – spend some or all of their lives parasitising animals and usually live on or burrow into the surface of the hosts skin

Question 7

• What are the physical adaptations of fleas?

Answer 7

Tube like mouthparts, laterally flattened, wingless, backwards pointing spines and bristles, enlarged hind legs

Question 8

• In which animals do fleas exist?

Answer 8

Animals that have a nest/burrow as fleas need to be somewhere where the host regularly comes back to e.g. dogs, cats, mice, rabbits, chickens, humans NOT chimps, cows

Question 9

• What are the two families of fleas that are of veterinary importance?

Answer 9

Ceratophyllidae & Pulicidae

Question 10

• What is the most common and therefore most important flea?

Answer 10

Ctenocephalides felis (cat flea)

Question 11

• What are combs?

Answer 11

Rows of dark spines that may bear on the head and first section of the thorax – used in identification

Question 12

• What are the direct effects of fleas?

Answer 12

Severe infestation of young/old animals can lead to anaemia, substances in flea saliva act as allergens causing FAD – hypersensitivity reaction; sensitised animals intermittently exposed to fleas appear to have the greatest reaction

Question 13

• What are the indirect effects of fleas?

Answer 13

Cat dog and human fleas can act as the intermediate host for Dipylidium caninum, the dog tapeworm – tapeworm eggs eaten by flea larva, hatch and form an infective cysticercoid within the adult flea, when adult flea is eaten cysticercoids enter the digestive tract and develop into tapeworms

Question 14

• Which pathogens can fleas act as vectors for?

Answer 14

Leporipoxvirus species (myxomatosis), Yersinia pestis, Rickettsia felis, Bartonella henselae, Haemoplasma species, Potentially feline leukaemia virus

Question 15

• How can fleas be controlled?

Answer 15

Chemical – repellents, adulticides, larvicides, ovicides, insect growth regulators (prevent flea larvae and pupae from develop or prevent the normal development of the exoskeleton)
Mechanical removal