Green stink bug

The native green stink bug (GSB) is the least damaging of the podsucking bugs.

Scientific name

Plautia affinis

Description

  • Adults are 8mm long with a green shield-shaped body and brown wing covers.
  • Nymphs are cream and yellow with prominent dark markings, changing to mossy green with dark markings on their back.
  • Eggs are similar shape to those of the green vegetable bug (GVB) but are olive-green and laid in small loose rafts of only 5–15 eggs.

May be confused with

Their 2-tone colouring distinguishes adult GSB from other green podsucking bug species.

Distribution and habitat

Widespread.

Hosts

All summer legumes, sorghum, and occasionally cotton.

Damage

In pulses, GSB damages only 10% as many seeds as GVB.

Life cycle

  • Adults typically invade summer legumes at flowering.
  • Females can lay over 400 eggs.
  • There are 5 nymphal stages. Nymphs usually reach a damaging size during mid to late podfill.
  • Usually only 1 generation develops per summer legume crop, unless temperatures are high.

Monitoring and thresholds

  • Inspect crops twice weekly from budding until close to harvest (the main risk period is at podding).
  • Beat-sheeting is the preferred sampling method for adults and nymphs.
  • Sample crops in the early to mid-morning when bugs are more likely to be at the top of the crop.
  • Look for the distinctive small egg rafts, which indicate a green stink bug is present.

Green stink bugs are not specifically included in the online calculator for podsucking bugs; therefore, if numbers are high, divide by 10 and include in the GVB column.

Natural enemies

  • Spiders, ants and predatory bugs are major predators of eggs and young nymphs, with mortality sometimes exceeding 90%.
  • Eggs may be parasitised by the tiny wasps Trissolcus basalis, T. oenone and Telenomus cyrus.

Control

  • Green stink bugs may be incidentally controlled by products used against the green vegetable bug.
  • Spring plantings are less at risk than summer-planted crops.
  • Where possible avoid sequential plantings of summer legumes.
  • Avoid combining cultivar and planting times that are more likely to lengthen the duration of flowering and podding.

Further information