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HORSE FLY
Key Features
- 1 inch or longer
- Brown or black in color
- Large, often colorful or iridescent
eyes
- Piercing, sucking mouth parts
Breeding Sites
- Animal carcasses
- Garbage
- Animal manure
- Decaying vegetables
- Decaying grass clippings and leaves
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Horn
Fly
Haematobia irritans (Linnaeus),
Muscidae, DIPTERA
DESCRIPTION
Adult -- The horn fly is half the
size of the common house fly and is more
slender, and the horn fly has
piercing-sucking mouthparts. This fly has
a brownish-gray to black body with a
slight yellowish cast, a set of parallel
stripes just behind the head, brownish-red
antennae and two wings with a smoky tinge.
The body is 3.5 to 4 mm long.
Egg -- Tan, yellow or white at
first, the egg darkens to reddish-brown
before hatching. It is oval-elongate in
outline, flat or concave on one side,
convex on the other and 1.2 mm long.
Larva -- The newly hatched
maggot, about 1.5 mm long, develops
through three instars to reach a mature
length of 6.5 to 7.5 mm. Slender and
white, it narrows to a point at the head.
Pupa -- Enclosed within the
shrunken skin of the last larval instar,
the pupa is 3.3 mm by 1.4 mm.
Barrel-shaped and white at first, the
outer covering (puparium) soon turns a
dark reddish-brown.
BIOLOGY
Distribution -- Believed to have
been introduced from France prior to 1887,
the horn fly now is found throughout the
continental United States and Canada.
Hosts -- Although this
blood-sucking fly is primarily a nuisance
to cattle, other animals such as sheep,
goats, horses, mules and dogs are also
bothered.
Damage -- Congregating on those
areas of the body where they are not
likely to be disturbed (base of horns,
neck, throat, belly, thighs, back, etc.),
horn flies suck blood from livestock
through their needle-like mouthparts. Such
feeding causes weight loss, reduced milk
production, and reduced vitality.
Furthermore, animals become so annoyed
that they may injure themselves while
attempting to dislodge the flies. Although
infestations of 4,000 to 10,000 flies per
animal are common in some parts of the
country, horn flies rarely exceed 500 per
animal in North Carolina.
Life History -- Favored by warm,
moist weather, horn flies emerge in spring
and seek out host animals. Although they
locate hosts most successfully during the
day, they usually disperse at night,
sometimes traveling as far as 5 miles.
Soon after initial feeding, females
periodically leave the host animal and
deposit 1 to 14 eggs in fresh cow manure.
Both male and female horn flies apparently
feed on the manure from time to time. Eggs
hatch 16 to 24 hours later.
Over a 4- to 5-day period, the larvae
feed in moist cattle dung and develop
through three instars. They then either
burrow about 4 cm (1.5 inches) into the
soil or remain in the manure and pupate.
During spring and summer months, a new
brood of flies emerges 5 to 7 days later
and repeats the cycle. As winter
approaches, newly formed pupae overwinter
giving rise to a new generation of flies
the following spring. Although most
prevalent in spring and summer, horn flies
continue to produce a new generation
approximately every 2 weeks well into
autumn.
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Face Fly
Peggy K. Powell, Ph.D., Board Certified
Entomologist
February, 1995
Although the face fly, Musca
autumnalis, is nonbiting, it is
nonetheless a troublesome pest of cattle.
The face fly's feeding activities,
normally on secretions of the animal's eye
and nose, often result in both annoyance
to the animal and transmission of disease.
Identification
Face flies are 3/8-inch long, slightly
larger than the house fly. A female face
fly is slightly darker than a female house
fly, but is otherwise almost identical.
The male face fly's abdomen is orange with
a black band down the center. The puparium
or pupal case of the face fly is unusual
in that it is white. An easy field
identification characteristic is that face
flies congregate in clusters of 20 to 100
on the faces of cattle.
Biology, Habits, and Life Cycle
Only the female face fly is a pest of
livestock. Males spend their time perched
on vegetation, awaiting mates. The males
feed on plant nectar and on the liquid
secretions of dung. Females feed on
protein contained in eye secretions, nasal
secretions, and saliva, not on blood. They
feed only during the daytime, resting on
fence posts or vegetation at night.
While the fly is feeding, the roughness
of its sponging mouthparts irritates the
cow's eye and increases tear production.
Face fly feeding can transmit bacteria to
the eye, increasing the likelihood of
bovine pinkeye and Thelazia
eyeworms.
The lifecycle for the
face fly is about 14-21 days long.
In addition to feeding on facial
secretions, face flies are sometimes
facultative blood feeders. This means that
although they don't bite cattle to obtain
blood, they will feed on blood that oozes
from scratches and other mechanical
wounds.
The female face fly lays her eggs only
in recently deposited (less than 15
minutes old) manure from grass-fed cattle.
They do not lay eggs in manure piles
around barns or in the trampled manure
associated with feedlots.
Face fly larvae, or maggots, develop
under the crust of the manure pat. When
they reach maturity, they move into the
soil next to the manure to complete their
transformation to the pupal stage. The
flies emerge as adults about a week later.
Development from egg to adult requires
from two to three weeks.
The face fly is active from early
spring through late autumn. Although face
flies prefer bright sunlight and do not
enter buildings during the summer, in the
fall adult face flies often seek out
hibernation places inside structures.
Economic Threshold
The treatment threshold for face flies
is five flies per animal. A population of
12 to 14 flies per animal will result in a
decrease in grazing by about one hour per
day. Twenty to 200 flies per animal is
considered a heavy population. Heavy face
fly populations can cause cattle to stop
feeding and move into a shady location to
escape the flies, resulting in reduced
animal production. Dairy cattle will
cluster together to reduce face fly
attack, thereby increasing heat stress and
reducing milk production.
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Deer
fly
Scientific name: Chrysops sp.
(Diptera: Tabanidae)
Facts: Deer flies are biting
flies with a pattern in the wing. They are
larger than a house fly but smaller than
most horse flies. They can bite human,
pets, and livestock. Larvae are large
maggots usually in slow moving water where
they feed on organic matter. Adult flies
can be found around lakes and ponds.
However, they are also a pest of livestock
in rangeland where the adults like to
roost in cedar trees. In Texas, they are
sometimes called "cedar flies".
Photo credit:
Bastiaan (Bart) Drees
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Black Flies
William F. Lyon
| Common Name
| Scientific Name
|
| Black Fly, Buffalo or Turkey
Gnat
| Simulium vittatum
Zetterstedt
Simulium venustum Say
Simulium jenningsi
Prosimulium sp
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| Adult
| Larva (top)
Pupa bottom
|
Certain species of adult black fly
females are fierce biters, whereas others
are strictly a nuisance by their presence
around one's nostrils, ears, arms, hands,
and other exposed skin areas. These flies
can discourage people from remaining in or
visiting certain recreational areas for
fishing, camping, hiking, golf, etc. when
the black fly season occurs. Children are
especially susceptible and may be severely
bitten while adults in the same area are
scarcely aware of the flies. Most
complaints in Ohio occur in early spring
(April to June) in hilly areas with
swiftly, flowing streams. Bites may appear
where clothing fits snugly against the
body, leaving a ring of bites just above
or below the belt line.
After the black fly finishes feeding,
bleeding may continue for some time. At
first, the bite site appears as a small,
red, central spot surrounded by a slightly
reddened, swollen area. Next, the area
becomes increasingly itchy, swollen and
irritating, sometimes for several days.
Some black flies readily attack people,
whereas others prefer domestic animals or
birds, often feeding during the daylight
hours and sometimes into the night. Flies
may become so abundant as to be drawn into
the air passages of livestock,
occasionally resulting in death. It is
believed that allergic reactions to bites
may be caused by histaminic substances in
the fly's saliva. These flies transmit a
disease of filarial worms, onchocerciasis,
which causes blindness in people in
Mexico, Central America and Africa in
addition to protozoan parasites,
leucocytozoonosis to turkeys and wild
birds. They may be potential transmitters
of encephalitis. It is suspected that the
expansion of black fly populations in Ohio
is likened to improvement in stream and
river water quality in recent years. As
with many aquatic insects, black flies are
very sensitive to water pollution.
Identification
Most species of adult black flies are
about 1/8-inch long (2 to 5mm), black gray
or even yellow colored, broad clear winged
without hairs or scales with heavy veins
near the anterior wing margin, have short
11 segmented antennae, large round eyes
(no simple eyes) and the thorax (middle
body region) is strongly convex, giving a
humpbacked, gnat-like appearance.
Small creamy-white eggs (rather
triangular) about 1/32-inch long (0.1 to
0.4mm) are deposited on the water surface
or attached in compact masses to stones
and vegetation in shallow fast-running
water (riffles) in streams and rivers.
Larvae, black to light brown colored,
cylindrical, about 1/4-inch or more long
(10 to 15mm), are quite active and
abundant, sometimes appearing as moss.
Pupa are boat or basket-shaped cocoons up
to 1/8-inch long (2 to 5mm) in the water.
Life Cycle and Habits
There are four species present in both
Ohio and Pennsylvania according to Dr.
Peter H. Adler, Department of Entomology,
114 Long Hall, Clemson University,
Clemson, South Carolina 29631 - Telephone
803-656-3111 (formerly conducted black fly
research in Pennsylvania).
- Simulium vittatum Zetterstedt
- This species is strictly a nuisance
attacking horses and cattle, but not
humans. It does fly around people's
faces. Breeding occurs in rich
productive streams such as polluted
(sewage) areas, at beaver dams, etc.
It is dark gray to velvety black.
(Widely distributed in North America.)
- Simulium venustum Say - This
species is a nasty biter feared by
fishermen and campers. The season
extends from May to September with
greatest numbers in June and July.
They are usually less troublesome in
late summer. It is recognized by its
white-marked tibiae (leg parts).
(Widely distributed, especially in New
England and Canada.)
- Simulium jenningsi - This
species breeds in huge rivers (one
mile or so wide). In Pennsylvania, New
England and other states, there is
currently a multimillion dollar
program applying a biological
larvicide known as Bacillus
thuringiensis Berliner subspecies israelensis
(B.t.i.) into streams and rivers to
control larvae before adult emergence.
- Prosimulium sp. - This
species occurs in early spring (April
to May). It is a nuisance by both
swarming and biting. Larvae occur in
small woodland streams. It is the
first black fly species to appear each
year.
Black flies often occur in enormous
numbers in the spring and early summer
months, especially in the northern
latitudes. Bites can be extremely painful,
and their mouthparts are somewhat similar
to those of a horse fly (bladelike and
piercing) in the female. Mouth parts are
rudimentary in the male. On people, they
crawl into sleeves, under neckbands,
around boot tops and other vulnerable
places, especially favoring the head just
beneath the rim of a hat. Bites can cause
swelling and numb soreness for many days.
There are records of both domestic animals
and people being killed in a few hours
through venomous bites and blood loss.
Death can result from suffocation as a
result of plugged nasal or bronchial tubes
and allergic reactions.
Flies usually bite during the day in
outdoor shaded or partially-shaded areas.
They do not bite indoors or late at night.
Some fly 7 to 10 miles from the breeding
sites, or are blown by wind even further
to feed on warmblooded animals and people.
Flies usually bite for about three weeks
before they die. Dark blue cloth attracts
more flies than white cloth.
Females deposit from 150 to 500 small,
shiny, creamy-white eggs on submerged
objects in the stream such as on water
plants, rocks, twigs, leaves, etc. or
simply scatter the eggs over the water
surface. Eggs darken then hatch in four to
five days at water temperatures of 70 deg
F. Eggs deposited in the autumn do not
hatch until the following spring when the
water warms.
Young larvae attach themselves to
submerged objects, molting six times as
they grow. They are elongate with the hind
part of their bodies swollen. A head fan
sweeps food material into the mouth. They
retain their position in the water by
means of sucker-like discs and tiny hooks
at the tip of the abdomen. Also, they may
spin a fine thread which aids in anchoring
them. Winter may be passed as larva.
Pupation occurs in a cocoon, open at one
end. Adults emerge in two to three days
when the water is warm. They are capable
of immediate flight and mating. The entire
life history spans about four to six
weeks, depending on species, water
temperature, available food, etc. There
may be four generations per year.
Black flies are attracted to mammals by
the carbon dioxide and moisture in exhaled
breath, dark colors, convection currents,
perspiration, perfumes, toiletries, etc.
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Key
Features
Other
Names
Other
Names
Other
Names
Other
Names
Key
Features
Developmental
Stages - Egg to Larvae to Pupa to
Adult, 12-27 days