Soybean – southern region

This page includes information specific to the southern soybean production region. See also the northern region soybean page.

Insect pest risk

High risk Reduced risk Low risk
Pod sucking bugs
  • Sequential plantings of soybean (pod sucking bug populations move progressively from early to late plantings, eventually building to very high levels).
  • Water stressed plants (set fewer pods and suffer greater % seed damage).
Late soybean plantings (greater risk of podsucking bugs).
Slugs and snails
  • Annual rainfall >500 mm
  • Above average spring–autumn rainfall
  • No-till stubble retained
  • Previous paddock history of slugs and snails
  • Summer volunteers and weeds
  • No sheep in enterprise
  • 450-500 mm annual rainfall
  • Tillage or burnt stubble only
  • Sheep on stubble
  • <450 mm annual rainfall
  • Drought
  • Tillage and burnt stubble
  • No volunteers and weeds
Other pests
  • Soybean close to lucerne increases the risk of early infestations of lucerne crown borer.
  • Use of non selective pesticides in the vegetative stages, especially synthetic pyrethroids, may flare Helicoverpa
  • Early spraying for podsucking bugs with synthetic pyrethroids at flowering flares mites and Helicoverpa
  • Low plant density (increased risk of lodging if infested with lucerne crown borer)
  • Water-stressed plants
    • greater risk of terminal damage by Helicoverpa and grass blue butterfly larvae
    • more attractive to soybean moth
Planting close to trees (more attractive to soybean moth)

Pest incidence

Pest Crop stage
Emergence Vegetative Flowering Podding Grainfill
Slugs and snails* Damaging  Damaging
Loopers Damaging Damaging Damaging
Aphids  Damaging  Damaging  Damaging
Native budworm (H. punctigera)  Damaging  Damaging  Damaging  Damaging
Grass blue butterfly  Damaging  Damaging  Damaging  Damaging
Lucerne crown borer  Damaging Present Present  Damaging
Mites  Present  Damaging  Damaging  Damaging
Soybean moth  Damaging  Damaging  Damaging
Podsucking bugs  Present  Damaging  Damaging
 * Snails may also cause grain con­t­a­m­i­na­tion at har­vest
Present Present in crop but gen­er­ally not dam­ag­ing
Dam­ag­ing Crop sus­cep­ti­ble to dam­age and loss.

Soybean crops can be attacked by pests at any stage from seedling to close to harvest.  Soybean leaves are more attractive to foliage-feeding pests than the leaves of other summer pulses. The crop becomes attractive to a greater range of pests from flowering onwards.

Key IPM strategies

  • Tolerate early damage. Minimise early season sprays to conserve beneficials.
  • Selective insecticides – Use biopesticides in vegetative soybeans prior to flowering to preserve beneficials:
    • Bacillus thuringiensis (Bt) is effective against loopers (under 12 mm)
    • NPV is effective agains Helicoverpa larvae (less than 7 mm long).
  • Consider the use of spray oils where aphid populations are low to moderate.
  • Use soft options that are pest-specific (e.g. pirimicarb is an aphid-specific product and softer on beneficial species than broad spectrum insecticides).
  • Controlling aphids with broad spectrum chemicals in the vegetative stage can flare aphids, mites, and Helicoverpa during subsequent crop stages.
  • Pests such as aphids often infest the edge of a field, not the entire field. Limiting spraying to borders where these pests occur enables the beneficial population to re-establish faster.

More information:

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