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Face Fly

Face Fly:

General Description

Credit: TristramBrelstaff

Credit: James Lindsey

 

  • The face fly is similar to the closely resembles the house flybut is slightly larger,
  • They are about 7–8 mm long.
  • Adults are grey in color with four dark stripes on the thorax, with a grey-black patterned abdomen.
  • The eyes in males almost touch when viewed from above.

Life Cycle and Common Characteristics

  • Females deposit eggs only in newly deposited manure from cattle on rangeland or pasture.
  • Eggs hatch within hours after deposition.
  • The larvae are yellow in color. They pass through three larval stages, growing to about 12 mm long, then developing into white pupae.
  • Adults emerge after 10 to 20 days of egg deposition.
  • Adults emerge from winter hibernationfrom March to April.
  • They feed on manure juices and plant sugars, and on secretions around the eyes, mouth, and nostrils of horses and cattle.
  • They also feed on the host’s blood through wounds caused by orse-fly
  • Most of the flies on the host are females searching for protein sources.
  • Male flies feed only on nectar and dung. They rest on branches and fences, attempting to catch a female and mate
  • At night, both sexes will rest on vegetation.
  • The life cycle (Egg to adult) takes about 3 weeks

Damage and Medical Implications

  • Female face flies typically cluster around the host animal’s eyes, mouth, and muzzle, causing extreme annoyance.
  • Face flies are economically important to livestock producers since they transmit eye diseases and parasites to cattle.
  • Contaminated females can transmit infectious bovine keratoconjunctivitis (pinkeye) and bovine rhinotracheitis to their hosts.
  • They are the source of nematode eye worm, Thelasia rhodesi, and infections in horses and cattle.
  • The female face fly’s persistent feeding habits produce significant annoyance and irritation.
  • The cattle’s defensive behavior can affect grazing patterns.