Beef Cattle Fly Control
Geographic Distribution
The face fly Musca autumnalis (De
Geer) was first reported in the U.S. in 1952 and has spread all
the way across the northern half of the U.S. and southern
Canada since and has now extended its range south into Alabama
in the southeast U.S. It is generally a pest along waterways or
areas of higher rainfall. However, irrigated pastures in the
more arid regions and pastures with tree cover will also
support large populations of face flies. Apparently the manure
in which the flies breed dries out too rapidly for the fly to
complete its larval development in the arid open ranges.
Livestock Losses
Losses to the livestock industry as a
result of the face fly is estimated by the USDA to be $68
million annually (1979). The losses from this pest are more
difficult to document than for the horn fly. However, the fly
has been implicated in the transmission of pinkeye which thus
makes it a serious pest.
The face fly is not a
blood sucker since its mouthparts are the sponging type like
those of the house fly. The face fly feeds on various animal
secretions. Tears, saliva, nasal mucus, blood and serum exuding
from wounds, perspiration and filth adhering to the animal hair
are all attractive to the face fly for feeding purposes. The
persistence and habit of the fly in congregating about the eyes
and nose of an animal cause the cattle to bunch and seek shade
or water. These evasive actions by the cattle undoubtedly
interfere with normal grazing patterns and thus cause reduced
milk and weight gain production.
Identification and Life History
Adult face flies closely resemble
house flies except they are slightly larger and darker. The
persistence and habit of congregating About the eyes and nose
of animals helps in distinguishing the face fly from the house
fly. The larger size (double) helps distinguish the face fly
from the horn fly. Most of the face flies on cattle are females
and the fly spends considerable time away from cattle which
makes control of this pest more difficult than for control of
horn flies which spend most of their time on cattle. The face
fly, like the horn fly, deposits its eggs in fresh cow manure.
The eggs hatch in 1-2 days; the larval stage lasts from 3-6
days and the pupal stage (transitional larvae-adult) lasts 7-10
days. Unlike the horn fly, which overwinters in the pupal form
in the pasture, the face fly overwinters as an adult in barns,
houses, other farm buildings and probably in trees, cracks and
crevices and wild animal shelters in pasture areas. It thus can
be a pest of humans around dwellings when it is migrating into
the overwintering site in the fall and out again in the
spring.
| 
