Unlocking the Power of Pest Scouting: Tips for a Pest-Free Environment

Spraying pesticides occurs when the cost of pest damage exceeds the cost of pesticides. Growers evaluate the cost of pest damage and only use pesticides when the cost of damage is greater than the cost of using pesticides.

Fremont, CA: A pest scout's job is not limited to inspecting just insects. They also check for diseases, nutrients, crop height management, irrigation, and crop stages. Walking through the crop, they observe the flowers, roots, stems, and leaves. This task is essential, as it helps companies control most pests and save money. Greenhouse employees could do other important tasks instead of wasting their time scouting. Our basic scouting outline can be used as a guide to achieve effective pest control.

Greenhouse preparation

The best way to scout a greenhouse is to divide it into sections. Make sure to spend a predetermined amount of time on each area, starting with plants nearest entryways.

Be sure to keep records

Scouting reports should include pest life cycles and growing conditions.

Pest life cycle: Monitor the type of pest, number of pests and eggs, development stage, crop issues, and damage types.

Growing environment: Record the temperature because it plays a key role in pest development-the warmer the temperature, the faster the life cycle.

Plant inspection

Plant growers are aware that certain plants are always susceptible to certain pests. Plants such as these require close monitoring and management, as well as preventative measures. Scouting involves examining the entire crop for color, height, and uniformity. Scan for pests by looking for plants that stand out from the others.

Select plants randomly for closer examination after completing this quick overall assessment. When detecting pests, we recommend using a hand lens of at least 10X magnification, whereas fungal diseases are usually visible from a distance. Examine the upper and lower surfaces of the leaves, flowers, and stems. There are relatively few pests that are found in a defined location on plants. Inspect mature leaves carefully along the midvein, where mites are usually found first. For root pests, remove a few plants from their pots in each section to inspect the roots.

Spider mite case: 

If the population hasn't reached an infestation level, spider mites are generally found under the leaves. On the upper side of the leaves, spider mite symptoms appear as small stippling, caused by their feeding. Many ornamental plants suffer from this problem because their diagnosis was made too late.

Population monitoring of pests

Monitoring populations with yellow sticky cards, indicator plants, and potato disks is common practice. Three to four yellow sticky cards should be placed per 1,000 square feet throughout the greenhouse. Place extra cards near doorways and vents.

Identify the crop's economic threshold

It is possible that some growers have already established their pest threshold level. Use the results from regular scouting to determine the pest threshold level for a crop or production. Usually, the level of pest tolerance varies from crop to crop: stock plants must be as pest-free as possible, while vegetable crops are more tolerant. Spraying pesticides occurs when the cost of pest damage exceeds the cost of pesticides. Growers evaluate the cost of pest damage and only use pesticides when the cost of damage is greater than the cost of using pesticides.