Soybean Sentinel Plot Report: August 26, 2025

Overview of Reports from Around Pennsylvania

This week, we have eleven reports from eleven counties. The fields that we scouted ranged from growth stages R5 to R7. As maturity approaches, yield gets set and insect pests become less relevant. Disease, particularly white mold, can remain relevant up to R7. Fortunately, for the fields that we scouted this past week, insect and pathogen populations remain low. Some fields harbor healthy communities of insects, dominated by grasshoppers and Japanese beetles, among others, but in the fields we scouted, they are not causing economic damage. Due to dry conditions, pathogens are less abundant, but scouting still revealed some minor infestations of Septoria brown spot and frogeye leaf spot. We also found some incidences of downy mildew and white mold. 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 their local populations, but these reports will indicate which pests are likely to be active in fields. Our reports are distributed via this weekly newsletter.

Reports

25 August 2025 – Lancaster County – Jeff Graybill

Field near Manheim

Growth stage: R6

• No insects noted
• Sudden death syndrome – Severity: 3
• Bacterial blight – Severity: 3
• Field suffering from drought

25 August 2025 – Columbia County – Anna Hodgson

Field near Bloomsburg

Growth Stage: R7

• No insects or diseases noted
• Beans are drying down and plants are losing leaves

25 August 2025 – Butler County – Stephen Campbell

Field near Saxonburg

Growth Stage: R6

• Grasshoppers – Severity: 1
• Japanese beetles – Severity: 1
• White-tailed deer – Severity: 1
• Septoria brown spot – Severity: 1

25 August 2025 – Perry County – Ashley Issacson

Field near Duncannon

Growth Stage: R5

• Japanese beetle – Severity: 1
• Grasshoppers – Severity: 1
• Green stink bug – Severity: 1
• Brown stink bug – Severity: 1
• White-tailed deer – Severity: 3
• Septoria brown spot – Severity: 1

25 August 2025 – Northumberland County – Anna Hodgson

Organic field near Danville

Growth Stage: R6

• Bean leaf beetle – Severity: 1
• Green cloverworm – Severity: 1
• Beneficial species present: lady beetles
• No diseases noted

25 August 2025 – Mercer County – Erin Cuprinka

Field near Mercer

Growth Stage: R5

• Japanese beetle – Severity: 1
• Cucumber beetles – Severity: 1
• Beneficial species present: lady beetles
• No diseases noted

25 August 2025 – Beaver County – Stephen Campbell

Field near Fombell

Growth Stage: R5

• Soybean aphid – Severity: 1
• Grasshoppers – Severity: 1
• Japanese beetle – Severity: 1
• White-tailed deer – Severity: 1
• Beneficial species present: Honey bees, lady beetles, web-building spiders
• No diseases noted 

25 August 2025 – York County – Heidi Reed

Field near Fawn Grove

Growth Stage: R6

• Japanese beetle – Severity: 1
• Downy mildew – Severity: 3

25 August 2025 – Franklin County – Tosh Mazzone

Field near Mercersburg

Growth stage: R6

• Japanese beetle – Severity: 1
• Green cloverworm – Severity: 1
• Grasshoppers – Severity: 1
• Beneficial arthropods: hover flies, web-building spiders, spine soldier bug
• White-tailed deer – Severity: 1
• Frogeye leaf spot – Severity: 1

25 August 2025 – Centre County – Adriana Murillo-Williams

Field near Bellefonte

Growth stage: R6

• Bean leaf beetle – Severity: 1
• Japanese beetle – Severity: 1
• Green cloverworm – Severity: 1
• Grasshoppers – Severity: 1
• Blister beetle – Severity: 1
• Silver spotted skipper – Severity: 1
• Beneficial arthropods: lady beetles
• Downy mildew – Severity: 1
• Frogeye leaf spot – Severity: 1
• Soybean vein necrosis – Severity: 1

22 August 2025 – Lebanon County – Del Voight/Tyler McFeaters

Field near Lebanon

Growth Stage: R5

• Grasshopper – Severity: 1
• White-tailed deer – Severity: 1
• Sudden death syndrome – Severity: 1
• White mold – Severity: 1
• Anthracnose stem blight – Severity: 1