WEBINAR: Insect Pest Management in Soybeans: What to Watch Out for in 2020

This webinar will focus on season-long insect pest management in soybeans. We will discuss biology, damage potential and management tactics for dectes stem borer, stink bugs and defoliating insects.

1 CEU in Integrated Pest Management

Presenter: Nick Seiter, Research Assistant Professor, Field Crop Entomology at the University of Illinois at Urbana-Champaign

Dr. Nick Seiter is a Research Assistant Professor of Field Crop Entomology at the University of Illinois. He develops management recommendations for insect pests of soybean and corn. He has a Ph.D. in entomology from Clemson University, and bachelor’s and master’s degrees in entomology from Purdue University.

• Dectes Stem Borer
  • Dark brown frass lines tunnels of soybean stem
  • Larvae are cannibalistic and will eat other larvae
  • Indication of larvae – a pile of sawdust when dectes larvae girdle the main stem
  • Management:
    • Chemical control is not recommended at this time – would take multiple applications to get control
    • Prevent lodging with a timely harvest
    • Identify infested fields during late summer and as harvest approaches: wilted petioles, larval tunneling, sawdust piles
    • More likely to have infestations in no-till fields
• Stink Bugs
  • Populations are typically highest in late R5/R6 in Illinois
  • Several species – green and brown
    • Brown stink bugs are more difficult to control with chemical
  • Brown Marmorated Stink Bug – invasive species increasing in population
    • Haven’t seen big issues in soybeans yet
    • Better at avoiding detection
  • Redbanded Stink Bug – major issue in the mid-southern US
    • More damaging than other species in soybeans
    • Mouth part is larger and can ingest more material
    • Stronger preference for soybeans and legumes
    • Has not been a major issue in Illinois yet
  • Management in Illinois
    • Most infestations occur late in season (R5-R6)
    • Preventative insecticide sprays are not effective because of short residual
    • Scout during R5-R6
    • Economic thresholds: Sweep-net nine stink bugs in 25 sweeps; drop cloth one stink bug per row-ft
• Defoliators
  • Most defoliation we see in Illinois is cosmetic – soybeans tolerate a lot of defoliation, especially in vegetative stages – economic threshold is 30%
• Armyworms and Stand Loss
  • Scout when soybeans follow a grass or in a field near wheat
  • Rye cover crop is also very attractive