External parasites of poultry and their control

              ilO.IUO^ NEW MEXICO COLLEGE OF AGRICULTURE AND MECHANICARTS
AND AGRICULTURAL EXPERIMENT STATION !      ' P." *
Press Bulletin 1002
(906 revised) "''.>.'?.- - jfl    ,<4*
EXTERNAL PARASITES OF POULTRY AND THEIR CONTROL "^""W--^*
Many kinds of external parasites are known to infest poultry. The list includes
lice, mites, ticks, and fleas, together with other less important forms. The total
loss caused by these parasites is enormous and their control presents a practical
problem wherever fowls are kept.
Lice
The louse is the most common of these parasites. It is a small, flattened insect seldom over 3/l6 inch in length and yellowish or gray in color. These insects
show considerable variation in form and structure, depending upon the part of the
body which they inhabit. In all, some 40 or 50 species of these insects have been
found on fowls. They are not blood-sucking parasites but have biting or cutting
mouth parts with which they feed upon bits of feathers and scales from the skin.
Their entire life cycle is spent on the body of the host. Therefore, any method of
control, to be successful, must be one which treats the individual bird. Furthermore, since most materials used to kill the lice do not prevent the eggs—or nits,
as they are called—from hatching, and do not last long enough to kill the young
lice which hatch from the eggs that are on the fowl at the time the material is applied, a follow-up treatment is necessary in about ten days. Fortunately, it is not
necessary to use a different method of treatment to destroy the different species of
lice, as with few exceptions the various methods of control are effective against
all species.
There are four important methods which may be used in controlling lice. They
are dusting, dipping, greasing, and fumigating. Claims have been made to the effect
that lice could be controlled by means of various substances placed in the drinking
water. However, the work of Parman and others in the United States Department of
Agriculture has shown that all of these claims are without foundation.
Dusting is one of the common methods for controlling body lice and if properly
done, using suitable materials, it is economical and effective. Sodium fluoride is
recognized as one of the best materials. In applying it a small amount of the powder
is dusted among the feathers on the breast, fluff, back, and head, and under the
wings. The powder may be applied from a can with a perforated top or it may be applied by the "pinch method." One pound of powder will treat about 100 hens. The
treatment should be repeated every week or ten days until the fowls are free of the
parasites.
The Florida Experiment Station reports excellent control from dusting with
ordinary commercial dusting sulphur. The procedure is as follows:  (1) The floors
and nests in the houses are given a generous dusting with sulphur.  (2) The soil of
the poultry yards is treated at the rate of two pounds of sulphur per hundred square
feet. (3) For a period of three weeks the dry mash fed contains five percent of fine
sulphur. This latter measure, it appears, is of value because the birds' head and
neck feathers become impregnated with the sulphur during feeding.
Dipping.—Sodium fluoride is also the recommended material for dipping. This
practice is not used so commonly as the other methods, as dipping can be carried out
only under favorable weather conditions; and furthermore, dipping does not seem to be
a very suitable treatment for birds. The dipping solution is made by using lukewarm
water to which has been added sodium fluoride at the rate of 1 ounce to each gallon
of water. Each bird is submerged in this solution, and held there for a few seconds
while the feathers are thoroughly ruffled so that the solution may penetrate to the