Stable flies primarily feed on the legs of horses and cattle but they can use all animals for a blood meal. In the absence of animal hosts, they bite people.
Peak stable fly breeding season is October thru January but they can breed year-round with wet summers. With a life cycle of 22 – 58 days, the female will deposit 500 – 600 eggs in four cycles. They lay eggs in wet piles of manure, hay, feed, fermenting weeds or grass cuttings, spilled green chop, seaweed on beaches, soiled animal bedding and sometimes in hay rings when the temperature warms in the spring. Do you have areas like that? Your damp organic matter may be the reason you have fly outbreaks.
A UF study found that stable flies can travel almost a mile from cattle to breed at horse farms following a blood meal and almost 10% had fed on humans. Sixty-four percent had fed on horses.
Those responsible for stable fly control need to be aware and extent of the problem. Small-scale and isolated efforts will not be effective. Everyone needs to work together. Efforts should be made to reduce man-made breeding sites of flies at agricultural, industrial and private properties. Oftentimes this can be accomplished by proper handling and disposal of animal and plant wastes.
For more information: http://edis.ifas.ufl.edu/pdffiles/IG/IG13300.pdf