Scouting Resources : Vegetable : Center for Agriculture, Food, and the Environment at UMass Amherst

What is scouting?

IPM pyramid depicting prevention practices at the base, then detection, mechanical control, biological control, and finally chemical control at the top. — Scouting plays a vital role in the detection of pests for IPM. Control of pests depends on the information obtained through scouting.

Scouting is the process of systematically checking a crop for pest populations and tracking those populations over time in order to determine how to best manage them. Growers can scout for insect pests, diseases, weeds, or even abiotic disorders. This is an important step in integrated pest management (IPM). The goal of scouting is often to arrive at a number of a specific pests per plant or leaf, which can then be compared to an economic threshold that has been developed through research; if pest populations in your field are above the economic threshold, it may be worth intervening with a pesticide.

When scouting, try to get an unbiased, representative sample of the crop. Pest densities are rarely distributed evenly across a field, so sampling randomly throughout a field will give you a more accurate idea of the pest pressure. Choosing sampling points in a zig-zag or “W” shape across your field and selecting individual plants to check by counting a predetermined number of steps between sampling points can help with this. At least 25 sampling points may be necessary to get a good sample of a large field, but fewer may suffice in smaller fields. Scouting for different pests may require checking different parts of the plant, including undersides of leaves or bases of stems.

Diagram of crop field with plants showing high pest pressure near a row of trees — Figure 2. A farmer sees heavy pest pressure on the edge of a field near the tree line. Image: S. Scheufele

Diagram of crop field showing that the majority of plants are pest-free. — Figure 3. After surveying the whole field, the farmer finds that only the plants near the treeline have heavy pest pressure, while the whole field is under threshold and no treatment is necessary. Image: S. Scheufele

While scouting, keep in mind some of the pests you should be on the lookout for based on the crop, season, and field history. This includes common diseases and the different life stages of insect pests and when they are likely to appear. Scout routinely and maintain a record of scouting results and management practices used. These records can be used to keep track of pest pressure and the efficacy of management practices, as well as to plan ahead and know what to expect in future years. You may use the scouting forms below for this purpose. Other scouting resources are linked below on this page.

See this UMass fact sheet for more information on how to scout effectively.

Pest Scouting Calendar

This calendar is designed to help growers track the important pest prevention, scouting, and monitoring actions for vegetable fields in Massachusetts. It focuses on the most common and damaging invertebrate pests in the region but does not cover all potential pests. The suggested timing for management actions is based on when pests are typically first observed. However, pest occurrence varies annually and may take place earlier or later than expected due to changes in weather, temperatures, or the arrival of new invasive species. Pest occurrence also varies geographically across different parts of the state. Use the “Notes” column to jot down observations or management adjustments specific to your farm. These notes can help inform your pest management decisions in future seasons.

Pest Scouting Calendar (English)

Pest Scouting Calendar (Spanish)

Our Pest Scouting Calendar is also available as a Google Calendar. Click here to view the calendar. In order to move or edit the pest listings for yourself, click on an individual listing, then click "Options", and choose to add the listing to your own calendar.

Scouting Guides

Crop-specific guidelines including descriptions of common pests in Massachusetts and what to look for when scouting. Use these before, during, or after scouting to identify major pests of the respective crop.

Allium Scouting Guide

Bean Scouting Guide

Brassica Scouting Guide

Cucurbit Scouting Guide

Potato Scouting Guide

Tomato Scouting Guide

Scouting Toolkit Inventory

Crop Scouting Forms

These sheets are designed for use while scouting to record pest counts and other relevant information:

General Purpose Scouting Sheet - this form is designed to be usable for a wide variety of crops and pests for which specific pest scouting sheets may not exist, so it doesn’t include information on any specific pests. It may also be useful for scouting smaller farms for which traditional thresholds do not apply. See the sample sheet for an example of how this resource can be used.

General Purpose Scouting Sheet

General Purpose Scouting Sheet (Sample)

Crop-Specific Scouting Sheets – these forms are designed for recording information while scouting common crops with predictable major pests, and they include details on these pests and guidelines on what information to record.

Allium Scouting Form

Brassica Scouting Form

Potato Scouting Form

Sweet Corn Scouting Form