Illinois Field Crop Applicators Practice Test

Which of the following is an indication to scout for pests in a crop?

1. Improper irrigation practices

2. Unusual changes in plant color or growth

3. Detection of beneficial insects

4. High soil moisture content

The correct answer is: Unusual changes in plant color or growth

Scouting for pests in a crop is critical for effective pest management, and unusual changes in plant color or growth serve as key indicators of potential pest problems. These changes can manifest as yellowing leaves, stunted growth, wilting, or other atypical symptoms that signal the presence of pests such as aphids, mites, or caterpillars, which may be feeding on the plant or causing stress. Detecting such anomalies allows growers to investigate further and determine if pest management actions are necessary. In contrast, the other options are not direct indicators of pest presence. Improper irrigation practices can lead to diseases or stress but do not specifically indicate a pest problem. The detection of beneficial insects, while important for understanding the ecosystem and potential natural pest control, does not itself signal the necessity to scout for pests. Lastly, high soil moisture content can affect plant health but is not a reliable sign of pest activity. Thus, unusual changes in plant color or growth are the most relevant cues for initiating pest scouting efforts.