Fly CONTROL

Biting flies are a nuisance, and their bites are painful and irritating.

- HEATHER SMITH THOMAS

When cattle are distracted by discomfort, they may spend more time fighting flies than grazing-slinging their heads over their shoulders to try to dislodge them, kicking flies off their bellies and constantly using their tails as flyswatters.

Bites of horseflies, deerflies and stable flies are very painful, and these flies go from animal to animal and can spread bloodborne diseases. Horn flies, by contrast, live their whole adult life on the host animal, and large numbers can suck enough blood to reduce weight gains.

CATTLE CONUNDRUMS

During fly season, some cattle may have thousands of these little flies covering neck, shoulders and back, with smaller numbers on the rest of the body or along the midline of the belly. After these flies feed and mate, the females move to the rear of the animal and fly to the ground as the animal defecates, immediately laying eggs in the fresh manure.

Horn fly eggs are generally laid in clumps on grass and other vegetation covered by the cowpat. After a time, which varies depending on temperature, the eggs hatch and maggots develop and grow. They then pupate in or below the pat, and the emerging adults later seek cattle hosts.

Horn flies live on the hosts — only flying up temporarily in a cloud of flies if the animal brushes them off — until they have sucked enough blood to mate and prepare to lay eggs. As summer moves into fall, horn fly larvae in manure mature only to the pupal stage and overwinter, waiting to become adult flies the following spring.

Other Ways to Reduce Fly Load