2011 Corn Earworm Trapping in Kansas

Source: Henderson State University

Trapping Corn Earworm in Kansas Offers Keys to 2011 Disease Issues

In 2011, Syngenta cooperated with Kansas State University to collect data on Corn Earworm (CEW) moth activity throughout eastern Kansas. The CEW moth trapping project utilized the KSU protocol.

Trapping started in June with 11 CEW traps placed across eastern Kansas at the following locations: Marysville, Centralia, Winchester, Atchison, Wamego, Girard, Yates Center, Ottawa, Thayer, Coffeyville and White City.

Each CEW team member checked the trap weekly, replacing the pheromone every two weeks. Once weekly, each location reported the number of moths captured. Data was compiled and reported on CEW moth activity as individual locations and as a group. The event created a lot of chatter early in the season as no one had ever seen a trap like the CEW moth trap in the corn fields. The teams were seeing higher moth counts each week as the growing season progressed. As we evaluated the moth flight increase throughout the summer, we sent out agronomy alerts about the high CEW moth pressure level. We know there is no direct correlation between moth flights and actual damage, but the alert advises growers to evaluate the field for damaged ears and the possibility of aflatoxin and mycotoxins in the field during harvest. During June and July we generally expect high flight patterns and early feeding on the ears. Typically, we should expect 2-3 flights of CEW moths in the western Corn Belt states. We also observed moth count anywhere from 6-1,170 moths in a single week. Threshold levels range from 5-10 moths in a 24 hour period. This level does require the application of an insecticide.

As we ended the month of August, we were not noticing the damage from the CEW that we saw a year ago, even though flights were higher than in past. The hot spots in the state seemed to be the very southeast corner of Kansas − Thayer and Girard areas. In the northeast corner of the state the hot spot covered Centralia to Atchison. We also found pod worms in the soybeans, which is another name for CEW. CEW can migrate from corn to soybeans as the pests seek soft tissue for feeding. Corn will become a harder material as it matures and the next best crop to feed on is soybean.

The summer of 2011 showed most diseases in corn and soybeans hit later than normal and really didn’t affect the health of the plant during the reproduction stages. Our research showed that more insects were working on soybeans this year than in the past. We knew the CEW or pod worms were coming, but unfortunately could not predict when. We did see an increase in insecticide use in soybeans this year and believe the ROI on that application more than paid for itself with the insect pressure we were seeing.

The CEW traps provided a significant amount of data and enabled growers to better understand pest issues in their crops. In addition, the data collected by Syngenta cooperators was added to the KSU information on pest activity.

Here’s the full wrap-up report.