Soybean Sentinel Plot Report: July 29, 2025

Overview of reports from around Pennsylvania

We have eleven reports this week from extension educators in ten counties. Their reports cover fields from growth stage R2 to R5, late flowering to pod fill stages. The reports indicate low pest populations in the soybean fields that we are scouting, but there are a few instances where deer or groundhogs are problematic. Our reports identify Japanese beetle, grasshoppers, and green cloverworm as the main insect pests that are active; these are typical for this time of year. Mexican bean beetle has started to show up in southern counties. Diseases are becoming more prevalent but remain in low abundance. Our reports indicate downy mildew, frogeye leafspot, and Septoria brown spot as the main diseases present; these are typical for this time of year. 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 and are available via the Penn State Extension website (then search for "soybean sentinel plot").

Reports

29 July 2025 - Mercer County - Erin Cuprinka

Field near Mercer

Growth Stage: R2

• Japanese beetle  – Severity: 1 
• Beneficial species present: bumble bee, fireflies
• Bacterial pustule – Severity: 1
• Septoria brown spot – Severity: 1

29 July 2025 - Perry County - Ashley Isaacson

Field near Duncannon

Growth Stage: R3

• Bean leaf beetle  – Severity: 1 
• Grasshoppers – Severity: 1 
• Japanese beetles – Severity: 1 
• Beneficial species present: bumble bee
• Septoria brown spot – Severity: 1

28 July 2025 - York County - Heidi Reed

Field near Fawn Grove

Growth Stage: R5

• Grasshoppers – Severity: 1 
• Green cloverworm – Severity: 1 
• Japanese beetle – Severity: 1
• Mexican bean beetle – Severity: 1
• Septoria brown spot – Severity: 1

28 July 2025 -  Butler County - Stephen Campbell

Field near Saxonburg

Growth Stage: R3

• Grasshoppers – Severity: 1 
• Japanese beetles – Severity: 1 
• White-tailed deer – Severity: 3 
• Septoria brown spot – Severity: 3

28 July 2025 -  Beaver County - Stephen Campbell

Field near Fombell

Growth Stage: R3

• Grasshoppers – Severity: 1 
• Japanese beetles – Severity: 1 
• White-tailed deer – Severity: 2
• Beneficial species present: bumble bees, honey bees, lady beetles, spiders
• Frogeye leaf spot – Severity: 1

28 July 2025 - Centre County - Adriana Murillo-Williams

Field near Bellefonte

Growth Stage: R2

• Bean leaf beetle – Severity: 1 
• Grasshoppers – Severity: 1 
• Japanese beetles – Severity: 1 
• Silver-spotted skipper – Severity: 1
• Beneficial species present: fireflies, honey bees, lady beetles, spined soldier bugs
• Downy mildew – Severity: 1

28 July 2025 - Columbia County - Anna Hodgson

Field near Bloomsburg

Growth Stage: R4

• Bean leaf beetle – Severity: 1 
• Grasshoppers – Severity: 1 
• Green cloverworm – Severity: 1 
• Potato leafhopper – Severity: 1
• Beneficial species present: honey bees, lady beetles, spiders
• Septoria brown spot – Severity: 1

28 July 2025 - Northumberland County - Anna Hodgson

Field near Danville

Growth Stage: R2

• Bean leaf beetle – Severity: 1 
• Green cloverworm – Severity: 1 
• Potato leafhopper – Severity: 1
• Beneficial species present: bumble bees, damsel bugs, fireflies, honey bees, lady beetles
• Downy mildew– Severity: 1

25 July 2025 - Lebanon County - Del Voight/Tyler McFeaters

Three fields: one near Bellegrove, one near East Hanover, one near Jonestown

Growth Stage: R3-R5

• Grasshopper – Severity: 1 
• White-tailed deer – Severity: 1 (Bellegrove only)
• Beneficial species present: bumble bees (Bellegrove only), lady beetles (Bellegrove and East Hanover)
• Downy mildew – Severity: 1 (Bellegrove and East Hanover)
• Frogeye leafspot – Severity: 1 (Jonestown only)

25 July 2025 - Franklin County - Tosh Mazzone

Field near Lemasters

Growth Stage: R2

• Grasshopper – Severity: 1 
• Japanese beetle – Severity: 1 
• Mexican bean beetle – Severity: 1 
• Soybean leafminer – Severity: 1
• Groundhog – Severity: 5
• Beneficial species present: carabid beetles, fireflies, hover flies, spiders, spined soldier bugs
• Downy mildew – Severity: 1
• Frogeye leafspot – Severity: 1
• Stem canker – Severity: 1