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

Share This Story