CONTROLLING THE
NORTHERN
FOWL MITE
Dr. Charlie Pitts
Professor Of
Entomology
A number of infestations of the
northern fowl mite have been
reported; therefore, producers
should be on the lookout for infes
tations in their layer houses. To
successfully control this pest, one
should know its biology.
The northern fowl mite,
Ornithonyssus Sylviarum, infests a
wide variety of domestic fowl and
wild birds and is the most impor
tant and common external parasite
of poultry. Feeding on blood,
heavy mite infestations can irritate
and stress birds, reducing egg pro
duction by 10 to IS percent
However, a production loss of
only a small percentage can add up
to significant losses over the total
life of a caged-laying flock. Heavy
populations can also reduce weight
gains and. in male birds, reduce
seminal fluid volume. Mites can
also annoy egg handlers and other
personnel.
Mites first congregate in the
vent area, then the tail, back, and
legs of female birds; however, they
are more scattered on male birds.
As the mite population increases,
feathers become soiled from mite
eggs, cast skins, dried blood, and
excrement The soiling produces
• Agricultural • Commercial • Residential
Partial In-Ground Tank Featuring Commercial Chain Link Fence
(5’ High - SCS approved)
• Retaining Walls • Bunker Silos
• Manure Storage, Etc.
the characteristic blackened feath
ers in the vent area. Scabs may also
form in the vent area. While death
due to actual anemia is rare, birds
with heavy infestations (50,000
mites/bird) can lose six percent of
their blood daily.
Mite populations can increase
rapidly sifter a bird has been first
infested, especially during the
cooler months and on young birds
(20 to 30 weeks of age). Newly
infested birds may support mite
populations in excess of 20,000
per bird in nine to 10 weeks. Mites
do not become established on birds
in large numbers until birds reach
sexual maturity. Also, birds older
than 40 weeks usually do not sup
port many mites.
The northern fowl mite, com
pletes its entire life cycle on the
bird, although they can survive off
the host for two to three weeks
under suitable conditions. Life
cycle stages consist of egg, larva,
two nymphal stages, and adult.
The eight-legged adult is only
l/26th of an inch long and is usual
ly dark ted to black. Females lay
two to five eggs in the fluff of
feathers after each blood meal.
Eggs hatch into six-legged larvae
within two days. All other mite
stages possess eight legs.
Nonfeeding larvae develop in
approximately nine hours and molt
into blood-feeding nymphs that
develop in one or two days. Sec
ond stage nymphs, like the larvae,
do not feed and molt to adults in
less than a day. The entire life
cycle can be completed within a
week undo- favorable conditions.
Mite Control
Control of northern fowl mites
in caged-layer operations is based
on efforts to prevent infestation
and to apply an acaricide when an
infestation occurs. Regularly
monitoring flocks for the presence
of mites will allow them to be
detected while the population is
low or isolated to a few birds.
A house should be clean and
mite-free before new birds are
moved in, and the new flock
should be mite-free. Once the
flocks are in the house, care should
be taken to prevent contamination
from the clothing of workers and
various equipment since mites can
live for a few weeks off the host.
Mites have been shown to be
readily transferred from an
infested house to an uninfested
house by contaminated egg flats.
Wild birds and rodents can harbor
and disseminate northern fowl
mites as well.
The detection of an initial low
mite population that can be con
trolled effectively and economi
cally is important in a mite
monitoring program. With early
detection, only part of a caged
layer house may need to be treated.
At least 10 randomly selected
birds from each cage row in the
entire house should be monitored
weekly. The vent area should be
examined under a bright light and
the feathers parted to. reveal the
mites.
Single caged birds often have
more mites than those caged in
groups and, because of variation in
susceptibility among birds, one
bird may have mites while its cage
mates are mite-free.
The following index is effective
for estimating infestation levels: 0
=no mites observed, I=one to two
mites, 2 = three to nine mites, 3 =
10 to 31 mites, 4=32 to 99 mites, 5
= 100 to 300 mites, 6 = 301 to 999
mites, 7 = 1,000 to 3,000 mites, 8 =
3,001 to 9,999 mites, 9 = 10.000 to
32.000 mites, and 10 = more than
32.000 mites. An average index of
five or greater fra all examined
birds generally indicates the need
fra chemical treatment.
The actual decision to treat is
influenced by flock age, time of
year, and distribution of the infes
tation in the house. It is usually not
economical to treat older birds
because their mite populations arc
unlikely to increase. A population
buildup is more likely in a young
flock. Mite populations can be
expected to increase in cooler
months and decrease in warmer
months. An infestation restricted
to one part of the house may not
spread, but the infested area should
be closely monitored. Detection of
mites in broiler-breeder operations
generally means the entire flock
must be treated.
National Shorthorn
Leadership Elected
LOUISVILLE, Ky. Bill
Rasor, Allen, Texas, will serve a
second term as the president of the
American Shorthorn Association
board of directors.
Rasor, owner and operator of
WHR Shorthorns, was reelected to
a second term at the organization’s
annual meeting in conjunction
with the National Shorthorn Show
at the North American Internation
al Livestock Exposition in
Louisville, Ky.
Rasor, completing a second
three-year term, was first elected
to the board in 1992. He and his
wife, Becky, have long been breed
leaders and promoters in both state
and national activities. Their chil
dren, Will and Ann, have been
active in the American Junior
Shorthorn Association. Will
serves as the vice president of the
American Junior Shorthorn Asso
ciation board of directors.
Reelected as the national vice
president was Dr. James Freed,
Chickasha, Okla. The Freed oper
ation, Double J Ranch, has estab
lished a national reputation for
producing strong, performance
oriented breeding cattle. Support
and dedication to the Shorthorn
breed is a family affair. Freed’s
wife, Beverly, is a former director
of the National Shorthorn Lassies.
Their children, Janet and Jetty,
Automatic Systems
■ ' •—"
USED
80 KW Diesel 100 KW Diesel
18 KW L.P. Gss
SERVICE MAXI-POWER D , SP^S|
330 Fonderwhlte Rd. Lebanon, PA 17042
Lancaster Farming, Saturday, December 24, 1994-C3
Chemical control of northern
fowl mites in caged-layer opera
tions requires direct pesticide
application to the vent region with
sufficient pressure (minimum 100
to 125 psi) to penetrate the feath
ers. The spray will have to be
directed upward from beneath the
cages to reach the vent.
A split treatment of a recom
mended active ingredient may
increase effectiveness since water
is held better when applied to wet
feathers. Mix half the insecticide
in the standard amount of water for
the first application, spray, and
then mix the other half in another
standard amount of water for the
second application.
Dust formulations can be pur
chased ready to use and may be
applied to caged-layers with a
power blower. Treatment is diffi
cult in broiler-breeder operations
where birds are not confined to
cages. Current recommendations
for sprays can be obtained from
your local extension agent.
have both achieved outstanding
success in the junior program.
Two new directors were elected
to the board for three-year terms by
the voting delegates from 21-dis
tricts in attendance. Ron Moore,
Jerseyville, 111., is one of three
members of the Hugh Moore Jr. &
Sons Shorthorn operation. Moore
has played a major role in the
development of their strong pro
gram and the continued growth of
the Shorthorn influence in his area.
Also elected to the board of
directors was Bruce Wallace, East
Bend, N.C. Wallace’s love of the
Short-horn breed began in 1940.
The owner and operator of Flint
Hill Farm is establishing a premier
breeding program of seedstock
genetics.
Retiring members having com
pleted six years on the board were
Dermy Jordan, Gibson City, 111.,
and Maurice Korthaus, Prospect,
Ky. Jordan was a two-term nation
al president.
Returning members of the
board are Robert Alden, Hamilton,
Mo.; Hale Charlton, Quin
cy, Calif.; Bradley Eisiminger,
Waynesburg, Pa.; Dale Rocker,
Seward, Neb.; and Doug Schrag,
Marion, S.D. Dr. .Roger E. Hun
sley serves as the breed’s execu
tive secretary-treasurer at the
American Shorthorn Association
offices in Omaha, Neb.