Lice

Question 1

• What is the body plan of lice?

Answer 1

Same as fleas and flies – head, thorax, abdomen and 3 pairs of legs

Question 2

• What are the physical adaptions of lice?

Answer 2

Claws, dorso-ventrally flattened, wingless

Question 3

• How are lice mouthparts adapted?

Answer 3

Either for chewing on epidermal debris, parts of feather and sebaceous secretions, or for sucking blood

Question 4

• Are lice holometabola or hemimetabola?

Answer 4

Hemimetabola – characterized by gradual and usually incomplete metamorphosis

Question 5

• What is the lifecycle of lice?

Answer 5

Egg -> Nymph -> Adult

Question 6

• How many hosts do lice have?

Answer 6

Lice are highly specialised and live on a single host species

Question 7

• What is pediculosis?

Answer 7

An infestation of lice

Question 8

• What are the direct effects of pediculosis?

Answer 8

Pruritus and dermal irritation, lowered production in farm animals, in severe infestations there may be loss of hair and local scarification, extreme infestation with suckling lice can cause anaemia, wounds may become infected

Question 9

• What are the indirect effects of pediculosis?

Answer 9

Lice are more important due to their direct effects, but do spread some pathogens e.g. pig louse is a mechanical vector of swine pox, lice can act as intermediate hosts for tapeworm Dipylidium caninum

Question 10

• What are the effects of lice in large animals?

Answer 10

Infested animals bite, scratch and rub themselves causing self-trauma

Question 11

• When can lice more easily effect small animals?

Answer 11

More common elderly animals, animals in very poor health or longhaired breeds that are unable to groom themselves

Question 12

• In birds, what does severe irritation caused by a lice infestation result in?

Answer 12

Restlessness, feather damage, feather plucking, cessation of feeding, death

Question 13

• What are the four suborders of lice?

Answer 13

Anoplura (sucking lice), Rhynchophthirina, Amblycera (chewing lice) & Ischnocera (chewing lice)

Question 14

• What are the characteristic differences between sucking lice and chewing lice?

Answer 14

Sucking lice have a small, narrow and elongated head, and legs are usually strong with crab like claws
Chewing lice have a large, broad rounded head, and legs are small and slender

Question 15

• What are the two common chewing lice species affecting guinea pigs?

Answer 15

Gliricola ovalis & Gyropus porcelli

Question 16

• How are lice spread?

Answer 16

By direct contact between animals, can only survive a few days off the host

Question 17

• Why is control relatively uncomplicated?

Answer 17

Lice spend their whole lifecycle on the host