Soybean Sentinel Plot Report: July 21, 2026

Overview of reports from around Pennsylvania

We have reports from extension educators this week from sixteen fields in eleven counties. Their reports cover fields from growth stage V2 to R3, illustrating variability across Pennsylvania. Our reports continue to reflect low insect and slug populations and low disease populations in the soybean fields that we are scouting. As usual for this time of year, our reports identify bean leaf beetle, grasshoppers, and Japanese beetle as the main insect pests that are active, but some other pests like soybean aphid and silver-spotted skipper caterpillars were found. Downy mildew and Septoria brown spot were the diseases found. Unfortunately, deer and groundhogs continue to be active in some fields. Scout your own fields to learn what is active in your area. Good luck!

Background on the project

This growing season the Pennsylvania Soybean Promotion Board is funding a Soybean Sentinel Plot Program, which is being managed by The Department of Entomology at Penn State and executed by Penn State Extension. In this effort, Penn State Extension Educators are regularly scouting about 25 'typical' soybean fields in about 20 counties across the state, reporting the populations of plant pathogens and insect pests that they find. Our goal is to inform the agricultural community about which pests are active across the state, so folks will have a sense of what to expect when they scout their own fields as part of an IPM program. It would be inappropriate to use these reports to justify insecticide applications.

In the reports below, pests that were found during scouting are listed with their severity, which is rated on a 1-10 scale with 10 being the highest. A severity score of 1 equates to 10% or less infestation or defoliation, a "2" aligns with 20% or less infestation or defoliation, and so on. Growers should be sure to check their own fields to determine your local populations, but these reports will indicate which pests are likely to be active in fields. Our reports are distributed via this weekly newsletter and are available via the Penn State Extension website (then search for "soybean sentinel plot").

Reports

20 July 2026 – Beaver County – Stephen Campbell

Field near Fombell

Growth Stage: R1

• Grasshopper – Severity: 1
• Deer – Severity: 1
• No diseases noted

20 July 2026 – Butler County – Stephen Campbell

Three fields: one near Marwood, one near Saxonburg, one near North Washington

Growth Stage: V7-R2

• Bean leaf beetle – Severity: 1
• Grasshopper – Severity: 1
• Japanese beetle – Severity: 1
• Septoria brown spot – Severity: 1
• Deer – Severity: 1

20 July 2026 – Northumberland County – Anna Hodgson

Two fields near Rushtown (one organic)

Growth Stage: V5-R4

• Bean leaf beetle – Severity: 1
• Grasshopper – Severity: 1
• Japanese beetle – Severity: 1
• Potato leafhopper – Severity: 1
• Tarnished plant bug – Severity: 1
• No diseases noted – Severity: 1

20 July 2026 – Centre County – Adriana Murillo-Williams

Field near State College

Growth Stage: R2

• Japanese beetle – Severity: 1
• Downy mildew – Severity: 1

20 July 2026 – Dauphin County – Heidi Reed / Brooke Coble

Field near Bellaire

Growth Stage: R3

• Grasshopper – Severity: 1
• Japanese beetle – Severity: 1
• Soybean aphid – Severity: 1
• Downy mildew – Severity: 1

20 July 2026 – Columbia County – Anna Hodgson

Field near Mainville

Growth Stage: R3

• Bean leaf beetle – Severity: 1
• Grasshopper – Severity: 1
• Green cloverworm caterpillar – Severity: 1
• Japanese beetle – Severity: 1
• Silver-spotted skipper caterpillar – Severity: 1
• Frogeye leafspot – Severity: 1

20 July 2026 – Lancaster County – Heidi Reed / Brooke Coble, Helen Sleat, Jacob Sherry

2 fields, one near Elizabethtown, one near Willow Street

Growth Stage: R2-R5

• Grasshopper – Severity: 1
• Japanese beetle – Severity: 1
• Soybean looper – Severity: 1
• Downy mildew – Severity: 1
• Septoria brown spot – Severity: 1

17 July 2026 – Indiana County – Stephen Campbell

Field near Brush Valley

Growth Stage: R1

• Bean leaf beetle – Severity: 1
• Japanese beetle – Severity: 1
• Slugs – Severity: 1
• Septoria brown spot – Severity: 1

17 July 2026 – Jefferson County – JohnMark Miller

Two fields: One near Sykesville, one near Troutville

Growth Stage: R1, V7, respectively

• Grasshopper – Severity: 1
• Japanese beetle – Severity: 1
• Groundhog – Severity: 1
• No diseases noted

17 July 2026 – Clarion County – JohnMark Miller

Field near Snively Corners

Growth Stage: V2

• Japanese beetle – Severity: 1
• No diseases noted

14 July 2026 – Perry County – Ashley Isaacson

Field near Blain

Growth Stage: R2

• Bean leaf beetle – Severity: 1
• Grasshopper – Severity: 1
• Japanese beetle – Severity: 1
• Mexican beetle– Severity: 1
• Silver-spotted skipper caterpillar – Severity: 1
• Groundhog – Severity: 4
• No diseases noted