Lice Flashcards
1
Q
Kingdom: Phylum: Class: Order
A
Animalia Arthropoda Insecta Phthiraptera
2
Q
Wings
A
None
3
Q
Divisions
A
Head, thorax, abdomen
4
Q
Body shape
A
Dorso-ventrally flattened
5
Q
Number of segments in antennae
A
3-5 segments
6
Q
Type of parasite
A
Obligate, permanent parasite
7
Q
Specificity
A
Host and site specific
8
Q
What is the claw size of a louse related to?
A
Fibre diameter
9
Q
Can lice survive off a host?
A
No, whole lifecycle is found on a host
10
Q
Pairs of legs
A
3
11
Q
Life cycle
A
Egg stuck to hair
No metamorphosis
3 nymphal stages
12
Q
Length of life cycle
A
2-3 weeks
13
Q
Two taxonomic groups lice are divided into
A
Anoplura
Mallophaga
14
Q
A
A = Anoplura
B = Mallophaga
15
Q
Anoplura: feeding strategy
A
Sucking lice Feed on blood or tissue fluids
16
Q
Anoplura: # of segments on antennae
A
5
17
Q
Anoplura: shape of head
A
Longer than broad and pointed
18
Q
Anoplura: hosts
A
Mammals only
19
Q
Anoplura: three families
A
Haematopinidae Linognathidae Pediculidae
20
Q
Genera of Haematopinidae family
A
Haematopinus
21
Q
Genera of Linognathidae family
A
Linognathus Solenopotes
22
Q
Genera of Pediculidae family
A
Pediculus Phthirus
23
Q
Anoplura: habitat
A
Coarse hairs (mane, tail) Eggs readily visible
24
Q
Anoplura: colour/size
A
Large, black or blue
25
Anoplura: transmission
Contact
26
Anoplura: treatment
Topical or oral insecticide
27
Mallophaga: feeding strategy
Biting lice Feed on epidermis, feathers
28
Mallophaga: shape of head
Head broad, rounded
29
Mallophaga: antennae
Thin, 4-5 segments
30
Mallophaga: hosts
Mammals and birds
31
Mallophaga: habitat
Fine body hairs Eggs concealed
32
Mallophaga: colour/size
Small, yellow
33
Mallophaga: transmission
Contact
34
Mallophaga: treatment
Topical only
35
Mallophaga: Genera with Mammal hosts
Damalinia Heterodoxus Trichodectes Felicola
36
Mallophaga: Genera with Bird hosts
Menacanthus Lipeurus Gonioides Goinocotes
37
Lice of the sheep
Body louse: Damalinia ovis Face louse: Linognathus ovillus Foot louse: Linognathus pedalis
38
A = Damalinia ovis
B = Linognathus ovillus
C = Linognathus pedalis
39
Damalinia ovis: features
Small yellow louse 30% properties affected Medium rainfall areas
40
Damalinia ovis: effect on host
Feeds on stratum corneum Hypersensitivity Irritation, rubbing "Pulled wool" Reduced wool production
41
Damalinia ovis: diagnosis
Find lice on sheep Part wool and look Minimum detection level 1000 lice per sheep Lice colonial and photophobic
42
How long do D. ovis eggs take to hatch?
10 days
43
How long is the lifecycle of D. ovis?
35 days
44
How long can D. ovis live off the host?
1 week
45
What is D. ovis affected by?
Temperature Moisture Sunlight
46
Effect of temperature on D. ovis
Optimum temperature 37 deg At low temperatures, eggs do not develop At high temperatures (above 39) few eggs are laid Lower numbers in summer
47
Effect of moisture on D. ovis
If humidity \> 90%, eggs do not hatch Heavy rain can kill eggs
48
Effect of sunlight on D. ovis
Exposure to sunlight kills lice Shearing removes 30-50% of lice as lice are exposed to UV radiation
49
When should D. ovis be treated chemically?
After shearing
50
What treatments are available?
Dips: Organophosphates or synthetic pyrethroids Pour-ons: Synthetic pyrethroids
51
Linognathus pedalis
Large blue louse Feeds on blood Found on feet, scrotum and belly Can develop at lower temperatures than D. ovis Attaches eggs to coarser hairs than D. ovis
52
What's special about L. pedalis?
Can survive on pasture for 18 days Can be transmitted through pasture
53
Linognathus ovillus
Uncommon Found on face
54
Lice of the goat
Damalinia caprae Linognathus africanus & stenopsis
55
Lice of the horse
Body louse: Damalinia equi Sucking louse: Haematopinus asini
56
A = Damalinia equi
B = Haematopinus asini
57
How is Damalinia equi transmitted?
Contact
58
How is Haematopinus asini transmitted?
Riding and grooming equipment
59
Damalinia equi
Small yellow louse Found on sides of neck and flanks
60
Haematopinus asini
Large dark louse Occurs on coarser diameter hairs Species can survive away from host for several days
61
A = Damalinia bovis
B = Haematopinus eurysternus
C = Solenopotes capillatus
D = Linognathus vituli
62
Lice of cattle
Body louse: Damalinia bovis Sucking lice: Short nosed cattle louse: Haematopinus eurysternus Tubercle bearing louse: Solenopotes capillatus Long nosed cattle louse: Linognathus vituli
63
Cattle sucking lice
Maximum numbers in winter Found on head, neck, back, tail Causes rubbing Larger numbers in sick animals
64
Lice of the pig
Sucking louse: Haematopinus suis
65
Haematopinus suis
66
Haematopinus suis
67
Haematopinus suis: Lifecycle
Eggs hatch 12-14 days Lice mature 12 days
68
Haematopinus suis: size
Very large, mistaken for a tick
69
Haematopinus suis: pathogenesis
May spread pig pox and swine fever Causes red welts on skin --\> production loss
70
Lice of the dog
Trichodectes canis Heterodoxus spiniger Linognathus setosus
71
A = Trichodectes canis
B = Linognathus setosus
C = Heterodoxus spiniger
72
Pathogenesis of Trichodectes canis
Can act as an intermediate host for the "flea tapeworm" D. caninum
73
Lice of the cat
Felicola subrostratus
74
Felicola subrostratus
75
Felicola subrostratus
Biting louse Pointed head Seen on aged or sick cats
76
Significance of heavy lice infestation in cats
May indicate underlying disease as cats are generally good groomers in health
77
Lice of poultry
Many genera, all biting Menacanthus Stramineus most common
78
A = Menacanthus Stramineus
B = Lipeuris caponis
79
Pathogenesis of poultry lice
Irritation Feather loss Poor growth Reduced egg production
80
Treatment of poultry lice
Dust baths, aerosols, vaporisers
81
Lice of humans
Head/body louse: Pediculus humanus, Pediculus capitis
Pubic louse: Phthirus publis
82
Pathogenesis of lice of humans
Vectors of typhus
83
