Even with crop protection technologies "purchased with the bag of seed", it is still very important to make representative surveys of fields to have an accurate indication of pest problems. Now is the time to finalize crop monitoring plans for 2008.

The general recommendation is to visit each field on a weekly basis. During the growing season this frequency may be relaxed, but at other times some fields may require checking more than once weekly. Without regular monitoring, it is difficult to tell if pest populations are increasing, decreasing, or remaining stable.

The scouting or monitoring pattern needs to be from representative areas of the field. Several patterns can be used when scouting a field. In general, one should enter about 50 paces beyond the end rows before making pest counts and observations. Border rows are typically avoided, unless there are specific reasons for surveying those areas.

There are three basic patterns for pest infestations in a field and the monitoring should be conducted accordingly.

When pests are expected to be uniformly distributed over the field (for example foliar diseases, corn rootworm beetles, European corn borer, and corn leaf aphids) the monitoring sites should be evenly distributed over the field. In a square field, this could mean one sample in each corner and one in the center.

Some pests are expected to be concentrated in particular areas of the field. For example, black cutworm, white grub, Phytophthora root rot, and nematodes may be distributed in high or low areas of the field, or other distinguishing features.

Some pests are expected to appear at field edges first. Examples include common stalk borer in conventionally tilled corn, armyworm, grasshoppers, spider mites, and plant viruses carried by insects. Monitor for these pests by walking fence lines and waterways.

It may be necessary to combine two or more patterns on one sampling date. Monitoring guidelines for some pests indicate that a certain number of consecutive plants be checked. When monitoring mobile insects, like corn rootworm beetles, random plants are surveyed.

Additional crop monitoring information can be found in the University of Illinois Field Crop Scouting Manual, which can be ordered at https://pubsplus.uiuc.edu/X880d.html. Insights on pest problems and management strategies across Illinois can be found in the Pest Management and Crop Development Bulletin, written by University of Illinois Extension specialists, available at http://www.ipm.uiuc.edu/bulletin.