Plan for monitoring corn earworm in sweet corn in 2013
Use a pheromone trap to monitor corn earworm activity in Michigan sweet corn in 2013.
Corn earworm is usually the most destructive insect pest in Michigan sweet corn. It can also infest other vegetable crops including tomatoes, green beans and peppers. Corn earworm larvae feed on the tips of sweet corn ears, making them undesirable for consumers.
Corn earworm adult moths prefer to lay eggs on fresh, green silks. Sweet corn fields that have fresh silks should be monitored with a pheromone trap to determine when the moths are present laying eggs.
When the catch is less than 10 moths per night in pheromone traps, it is likely there is not enough egglaying activity to justify treatment. Otherwise, when the catch is more than 10 moths per night in pheromone traps, it is likely there is sufficient enough egglaying taking place to justify treatment with an insecticide labeled for corn earworm with retreatment necessary (depending upon temperature) every three to five days until the silks turn brown. For more information on managing sweet corn for corn earworm, refer to Managing Insects in Commercially Grown Sweet Corn from Purdue Extension. For information on insecticides and application rates, refer to MSU Extension Bulletin E-312, Insect, Disease and Nematode Control for Commercial Vegetables.
Heliothis traps for monitoring corn earworm are available online at Gempler’s or Great Lakes IPM. Pheromone lures to attract corn earworm adult moths for monitoring are also online at Great Lakes IPM and should be changed every two weeks.
To learn more about monitoring for corn earworm as well as other pests in sweet corn fields in 2013, growers are encouraged to attend the sweet corn session at the Great Lakes Expo held December 4-6 at the DeVos Place Convention Center in Grand Rapids, Mich. Registration is now open for the Great Lakes Expo.