The cherry fruit fly emerged in orchards this week, and all trees, whether in a backyard or commercial orchard, are required to use an insecticide to battle this insect.
Lynn Long, Oregon State University Extension horticulturist, announced the emergence of the cherry industry’s chief pest Wednesday, May 24. He said the entire cherry growing area, including the cities of The Dalles, Mosier and Dufur, are within a fruit fly control district. People with cherry trees must apply an insecticide immediately and then reapply it about every seven days through cherry harvest.
For homeowners, the recommended sprays include any product with spinosad or Malathion as an ingredient and labeled for use on fruit trees.
The cherry fruit fly overwinters in a cocoon as a dormant pupa and emerges in response to the rise in temperatures in the spring. The adult fly mates and begins egg laying within five to seven days after emergence.
Eggs are laid beneath the skin of the cherry and hatch into a worm about three days later.
The worm feeds within the cherry fruit, maturing in about two weeks. The worm then eats its way out of the cherry, falls to the ground, and goes into the resting stage until the next year. There is only one generation of cherry fruit fly per year. Fly emergence occurs over several weeks, however, which requires a season-long control program, Long said.
To obtain a free pesticide spray guide, contact the local extension office at 541-296-5494.