Order PHTHIRAPTERA (Lice or Kuto)
Wings are absent
Body flattened dorso-ventrally
Eyes are absent or reduced
Head, thorax, and abdomen distinct
Metamorphosis incomplete or gradual (Hemimetabolous development)
Whole life cycle is spent on the host
Lice are permanent ectoparasites of birds and mammals
Cause pediculosis or lousiness or louse infestation
Lice are classified into two suborders:
1. Anoplura – sucking lice
2. Mallophaga – biting lice
Anoplura
Head elongate and narrower than the thorax
Parasites of mammals only, usually host specific
Blood suckers with piercing stylets
1. Family Haematopinidae – no eyes, temporal angles present, legs almost equal in size, paratergal plates
present, has one row of hairs on each abdominal segment
Genera and species:
Haematopinus suis – swine
H. asini – horses
H. eurysternus – cattle
H. quadriperstus – cattle
H. tuberculatus – carabaos and buffaloes
H. nigricantis – Luzon brown deer
Life cycle:
Eggs or “nits” are attached to the hair close to the skin usually at the region of the neck,
shoulder, flank,a nd lower abdomen. Eggs are white to dirty white in color. A female requires a blood
meal before laying eggs. Eggs hatch into first nymph after 2-3 weeks. Nymph molts 3 times within 16
days (5 days/molt) before developing into an adult. First molt occurs after 6 days; second molt – after 4
days; third molt – after 5 days. Adult becomes sexually mature after 3 days. Egg to egg cycle take 23-32
days.
2. Family Linognathidae – no paratergal plates, smaller and more slender than Haematopinus, temporal
angles present, legs unequal, the first pair being the smallest
Genera and Species:
Solenopotes capillatus – cattle
Linognathus vituli – cattle (long-nosed cattle louse)
Linognathus africanus – goats
Linognathus stenopsis – goats
L. pedalis – sheep
L. ovillus – sheep
L. setosus – dogs
Life Cycle:
Eggs are attached to the hair usually on the dewlap, shoulders, sides of the neck, and face anywhere in
the body in heavy infestation. Eggs are dark blue in color and hatch into nymph after 10-13 days. Nymph molts 3
times within 15 days (5 days per molt). Egg to egg cycle requires 23-27 days.
3. Family Pediculidae – eyes present, legs almost equal, paratergal plates present
Genera and Species:
Pediculus humanus capitis – human head louse
Pediculus corporis – human body louse
Pedicinus eurygaster – macaque
Pedicinus obtusus – monkey, baboons
Phthirus (Pthirus in google) pubis – crab louse or pubic louse of man and may occur in the pubic
region, may also occur in the armpit, eyelashes, eyebrows, beard, mustache
(Life cycle skipped, refer to hardcopy)
4. Family Hoplopleuridae – paratergal plates project apically from the body. Tergal and sterna plates
usually distinct
Genera and Species:
Polyplax serrata – mouse
Polyplax spinulosa – mouse rat
Polyplax acanthopus – mice
Polyplax captiosa – mouse
Polyplax pacifica – rats
Haemodipsus ventricosus – rabbits
5. Family Echinophthiriidae – body densely clothed with thick setae, sometimes modified into scales,
sterna plates absent
Genus and Specie:
Antarctophthirus microchir – sea lions
Importance of sucking lice:
Effects on the host:
Cause irritation, itchiness (pruritus) leading to biting, scratching, restlessness, nervousness,
loss of blood, loss of sleep, interrupted feeding, loss of weight, loss of milk, shaggy rough coat,
matted hairs, thickened and darkened skin (vagabond’s disease). Licking results in bruises,
wounds, hairballs in the stomach. Foot louse cause lameness.
Haematopinus suis – may transmit swine fever virus (hog cholera)
Reduce body resistance to viral and bacterial diseases
Transmitter of:
o Borrela recurrentis – cause of epidemic relapsing fever
o Rickettsia prowazekii – cause of typhus fever
o Pasteurella tularensis – cause of tularemia
Transmission is through direct contact, sleeping together, use of same comb, clothes,
swimming trunks, bed sheets, toilet seat
Mallophaga (chewing lice)
Head broader than the thorax
Mouthparts adopted for biting or chewing
Mandibles present. Feed on epithelial debris, feather of birds, dried blood from small wounds, dried
bbjfhdf and tissue fluids.
Parasites of mammals and birds. Those parasitic on mammals have 1 claw while those on birds have 2
claws
Ischnocera – antennae filiform and visible at the sides of the head. No maxillary palpi. 2 claws per leg in species
occurring both in mammals and birds
Mammals – Bovicola, Damalinia, Trichodectes, Felicola
Birds – Anaticola, Columbicola, Chelopistes, Cuclotogaster, Goniodes, Goniocotes, Lipeurus
Amblycera – antennae lie in groove in the sides of the head and are not readily seen.
Mammals (one claw per leg) – Gyropus, Gliricola, Heterodoxus, Trimenopon
Birds (two claws per leg) – Menacanthus, Menopon, Holomenopon
