Soybean Sentinel Plot Program July 18, 2017

Reports indicate low pest populations in the soybean fields around the state. For most issues, there is little economic return in applying insecticides.
Soybean Sentinel Plot Program July 18, 2017 - News

Updated: August 18, 2018

Soybean Sentinel Plot Program July 18, 2017

Our reports from this week identify bean leaf beetles, Japanese beetles, and grasshoppers as the primary defoliators. Soybean aphid can be found in some fields, but populations remain low. Remember that vegetative stages soybeans can tolerate up to 25% defoliation without dropping yield (reproductive stage beans can tolerate 15%), so do not overreact if you find some feeding damage in your fields. For diseases, reports of Septoria brown spot and frogeye leaf spot appeared this week, but populations seem low.

The Pennsylvania Soybean Promotion Board is funding a Soybean Sentinel Plot Program, which is being managed by Penn State Extension and The Dept. of Entomology at Penn State. In this effort, Penn State Extension Educators are regularly scouting 25 or so 'typical' soybean fields in nineteen counties across the state, reporting the populations of plant pathogens and insect pests that they find. Our goal is to keep folks aware of pests so that they will then scout their fields as part of an IPM program. It would be imprudent to use these reports as the basis or justification for an insecticide application or including insecticides in with a post emergence herbicide application.

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 give you a sense of what pests are active in fields. Our reports are distributed via this weekly newsletter.

Reports

18 July 2017 - Crawford County - Joel Hunter

Growth stage: V6-8

  • Minor Japanese beetles feeding
  • Minor infestation of Septoria brown spot

18 July 2017 - Armstrong County - Rachel Milliron

Near Dayton

Growth stage: R1

  • Bean leaf beetle - Severity: 1
  • Japanese beetle - Severity: 1
  • Grasshoppers - Severity: 1
  • Septoria brown spot - Severity: 1

17 July 2017 - Franklin County - Kelly Patches

Near Greencastle

Growth stage: R2

  • Japanese beetle - Severity: 1
  • Green cloverworm - Severity: 1
  • Bean leaf beetle - Severity: 1
  • Potato leaf hopper - Severity: 1
  • Grasshoppers - Severity: 1
  • Soybean aphid
  • Beneficial arthropods present: spiders, lady beetle, bees
  • No diseases noted

17 July 2017 - Blair County - Zach Larson

Near Martinsburg

Growth stage: R1-2

  • Japanese beetle - Severity: 1
  • Green cloverworm - Severity: 1
  • Grasshoppers - Severity: 1
  • No diseases noted

17 July 2017 - Columbia County - Chris Houser/Joel Imgrund

Growth stage: R1

  • Japanese beetle - Severity: 1
  • Grasshoppers - Severity: 1
  • Potato leaf hoppers - Severity: 1
  • Beneficial insects present: Honey bees and minute pirate bugs
  • No diseases noted

17 July 2017 - Northumberland County - Chris Houser/Joel Imgrund

Growth stage: R1

  • Japanese beetle - Severity: 1
  • Grasshoppers - Severity: 2
  • Potato leaf hoppers - Severity: 1
  • Green cloverworm - Severity: 1
  • Honey bees and other bees present
  • No diseases noted

17 July 2017 - Union County - Chris Houser/Joel Imgrund

Growth stage: V5

  • Japanese beetle - Severity: 3
  • Grasshoppers - Severity: 3
  • Potato leaf hoppers - Severity: 1
  • No diseases noted

16 July 2017 - Elk County - Nicole Carutis/Mellissa Rathbun

Near Kersey

Field was disked, then soybeans were drilled in 7.5" rows after last year's corn

Growth stages: V5

  • Japanese beetles - Severity: 1
  • Blister beetles - Severity: 1
  • Frogeye leaf spot - Severity: 1

16 July 2017 - Jefferson County - Nicole Carutis/Mellissa Rathbun

Near Brockway

Field was chiseled, Planted, 30" rows, 1st year bean after corn, double Inoculated

Growth stage- V3

  • Bean leaf beetle - Severity: 1
  • Potato leafhopper - Severity: 1
  • Beneficial arthropods present: Daddy long legs
  • Frogeye leaf spot - Severity: 1
  • Septoria brown spot - Severity: 1
  • No diseases noted

15 July 2017 - Franklin County - Kelly Patches

Near Fayetteville

Growth stage: V6-8

  • Field was sprayed with a post-emergent herbicide, and they unnecessarily include an insecticide
  • Japanese beetle - Severity: 1
  • No diseases noted

13 July 2017 - Cambria County - Zach Larson

Near Loretto

Growth stage: V7-9

  • Japanese beetles - Severity: 1
  • Green cloverworm - Severity: 1
  • No diseases noted

13 July 2017 - Clinton County - Don Woodring

Near Eastville

Growth stage: V4-5

  • Slugs are still active on new foliage
  • Japanese beetles present
  • Silver spotted skipper caterpillars present
  • No diseases noted

12 July 2017 - Lebanon/Lancaster County - Del Voight / Jeff Graybill /Dennis Schoffstall

Growth stage: R2-3

Ten fields across both counties

  • Japanese beetle - Severity: 1-2
  • No diseases noted

Authors

Insect ecology Plant-insect interactions Conservation biological control Chemical ecology Gall insects

More by John Tooker, Ph.D.