HESSIAN FLY

A, Infested wheat plant. B. Uninfested. C Infested stubble with puparia exposed. a. Puparium, b, larva; c. adult male; d, egg-laying female and eggs: e, puparia in base of stubble. (a, b, c, and d. about six times natural size; all others, natural size.)

HESSIAN FLY

In the winter-wheat region, the hessian fly injures wheat chiefly, but it may also attack barley and rye. The flies lay their eggs in the grooves of the upper surface of the leaves of young wheat. One female may deposit several hundred eggs and infest many plants as she flies over the grain field. The eggs hatch in 3 to 12 days, and the small red maggots make their way down the leaf and behind the sheath, where they begin feeding on the tender tissues of the plant. The maggots are full-grown in 2 to 4 weeks. They are then glistening white, but they soon turn brown, forming puparia or "flaxseeds." Adults emerge from the overwintering "flaxseeds" in early spring to lay their eggs. Small tillers of infested plants die; jointed tillers often break over and fall to the ground before harvest.

Adults that emerge from "flaxseeds" in stubble and in volunteer plants of harvested fields infest early fall-seeded fields, with resultant stunting and death of tillers and plants.

Control: The control of the hessian fly in wheat depends on good farm management and community cooperation. The methods that have proved to be the best are as follows: Plow under the stubble of the last crop, where practicable, soon after harvest. Destroy volunteer plants so far as possible before the seeding period of the next crop. Prepare a good seedbed and maintain a high fertility in the soil. Use only the varieties of wheat recommended by your State agricultural experiment station or county agent, and sow at recommended "safe" dates for your locality. Cooperate with neighboring farmers in following approved practices.