Scouting for Pest Problems

— Written By and last updated by Patricia Burch

One of many important components of growing crops is scouting for pests. Scouting is described as a precise assessment of pest pressure and crop stages in order to evaluate economic risks due to pest pressure. It also helps with making decisions for potential management of pest problems that have reached economic threshold. Economic threshold is the point which economic loss will occur if present situation isn’t addressed. As an example, in this article I will discuss soybean scouting.

This time of year growers should have scouting soybean fields on their radar. If time permits, this should be completed on a weekly basis beginning July 25 to

mid-September. Fields that are in the flowering stage from the end of July through August should be given a higher priority for scouting.

Corn earworm moths are attracted to blooming fields and typically lay more eggs in open-canopied beans on high spots and lighter soils. From mid-August to mid-September, pay close attention to soybean fields that are adjacent to cotton fields because these areas can often have the highest looper populations. Scouting for stinkbugs can be difficult because they are not found in all areas of the field. Stink bug damage can occur from pod set to when pods begin to yellow, greater injury typically occurs during early pod fill.

The most important consideration for any field-scouting program is to get a representative sample. If you can’t scout all your fields, at least get a sample representative of the varieties and planting dates each week. Don’t treat all fields based on what is found in one variety or maturity group. Also, be sure to walk out into your fields to get a better idea of what pests are present. You do not want to rely on just what is found along the border of your fields because it could give you a “false reading” of overall activity within the field.

Foliage damage in soybeans due to foliage feeding insects is quite simple to evaluate. The threshold for foliage feeding pests is 30% loss throughout the canopy during the vegetative stages up to two weeks prior to flowering and 15% foliage loss throughout the canopy two weeks prior to flowering through the reproductive stages up to R6-R7.

For more information regarding integrated pest management and current pest news, visit the Integrated Pest Management website.