Lice Flashcards
Lice (5)
-dorsal-centrally flattened
-flightless insects
-terminal claws used to grasp hair
-chew skin OR suck blood
-permanent, obligatory ectoparasites
Outbreaks of lice indicate
Poor husbandry / condition
Two suborders of Lice
- Mallophaga (Chewing Lice)
- Anoplura (Sucking Lice)
Mallophaga (Chewing Lice) (6)
-found in fine body hairs
-eggs are concealed
-head as wide/wider than thorax
-small, yellow
-transmitted via contact
-treatment = topical ONLY
Anoplura (Sucking Lice) (7)
-narrow head in relation to thorax
-mouthparts used for sucking blood
-found in coarse hairs at the extremities of body (ex. Mane, tail)
-eggs readily visible
-large, black/blue
-transmitted via contact or on pasture
-treatment = topical or oral
Mallophaga (chewing lice) have a ___ while Anoplura (sucking lice) have a ____
Chewing: large mandible/head for chewing skin
Sucking: mouthparts like a tube for sucking blood
Hemimetabolous development means there is
No true metamorphosis
General life cycle of lice (2)
-Hemimetabolous
-all stages on host (eggs —> 3 nymph stages —> adult)
Unlike fleas, lice have
High host specificity
Transmission of lice is favoured in
Overcrowded conditions (transmission is via contact)
Lice eggs (3)
-on host
-hatch after ~7-10 days
-resistant to insecticides
One of the few lice species that can survive off the host (for only 18 days) is
Linognathus pedalis (foot louse) of sheep
Bovicola ovis (sheep body louse) (5)
-small, yellow
-chewing louse
-distribution on body dependent on temperature and fibre diameter
-life cycle takes 35 days
-can live off host for 10 days
B. Ovis is most prominent during
Autumn/winter (low temperatures)
Transmission of B. Ovis is greatest when
Wool is short
Effect of B. Ovis on the sheep host (4)
-irritation leading to rubbing
-reduced wool quantity and quality
-denial of sheep to sale yards
-susceptibility to blowfly strike
Best methods to control sheep body louse (B. Ovis) (3)
-isolate infested stock from non-infested
-split shearing
-biosecurity of shearers
Linognathus pedalis (sheep foot louse) (3)
-sucking louse (feeds on blood)
-large, blue
-can live on pasture up to 18 days
Menacanthus stramineus (poultry/fowl louse) (3)
-chewing louse but then feeds on blood
-lives on skin
-causes: irritation, poor growth, reduced egg production
Haematopinus suis (Pig) (4)
-sucking louse
-very large (can be mistaken for a tick)
-causes red spots on skin
-transmits pox and swine fever
Lice of cattle (3)
-sucking
-maximum numbers during winter
-cause rubbing/irritation
