It attacks fly pupa inside and outside the barn. Maggots hatch in a day, feed on the dung for 3-5 days, pupate in the soil for five days, and then emerge as adults. Face flies cause extreme annoyance to cattle on pasture all summer. Maggots develop on cow manure, then pupate in the soil. The entire life cycle takes about 2-3 weeks.
Cattle grubs damage the animal ' s tissues, further reducing the carcass's value .
They affect the animal ' s ability to graze efficiently, reduce weight gain, and delay first lactation. Larvae emerge after 4-7 days and burrow into the skin, cause considerable irritation, and then migrate through the animal ' s connective tissues. After two months, the grubs emerge, drop to the ground, and pupate in pasture litter and soil for 2-8 weeks before adult flies emerge. No pesticides are currently registered for control of cattle grubs on lactating dairy cattle. Mange mites cause dermatitis, hair loss, scabbiness, and milk production decline.