CHAPTER XVII 
EXTERNAL PARASITES 
LICE 
General nature. Bird lice are wingless parasitic insects with 
mouth parts adapted to biting, not sucking. Lice in general perma- 
nently infest the host bird except when moving to other individuals. 
Opportunity exists for this migration on the roost, the nest, during 
copulation or while a hen is hovering chickens. Occasionally lice 
which are normally parasitic for the hen, guinea-fowl or turkey 
will be found on another species in close contact. 
Lice feed on epidermal products such as feathers, 
scales and the skin itself. Blood dried on the skin 
may be eaten but lice are not blood suckers. 
Injury caused by lice. Their presence causes 
pruritis set up by their claws and mouth parts. 
Excessive infestation undoubtedly is a serious hin- 
drance to normal growth and development. Brood 
hens are annoyed in some cases to such an extent 
that there is interference with incubation. In the 
Fic. 38. Head Southern States, there is a heavy mortality among 
at pc gore chicks hatched by hens after April 1, which may be 
enlarged. (Bish- attributed to the heavy infestation by lice. Bishopp 
opp and Wood) 4 Wood regard symptoms of lice infestation as 
consisting of droopiness, lowered wings and ruffled feathers. In 
grown fowls heavy infestation may be tolerated without causing ill 
effect. In other cases there is reduction in egg yield and loss of 
weight. 
Species of lice. More than 40 species of lice occur on domesti- 
cated birds. Some species are restricted to one host, while others 
infest several different host species. Bishopp and Wood state that 
seven species are very commonly found on chickens in the United 
States, four or five on pigeons, two or three each on geese and ducks, 
three on turkeys and several each on guinea fowl and peafowl. 
These are: On chickens, the head louse (Lipeurus heterographus), 
the body louse (Menopon biseriatum), the shaft louse (Menopon 
pallidum), the wing louse (Lipeurus variabilis), the fluff louse 
208. 
