Spined Citrus Bug
Biprorulus bibax
Native green shield bug with distinctive shoulder spines. Primarily a citrus pest but can appear on tomatoes and capsicums.
Background
Spined citrus bug is native to eastern Australia. It is primarily a pest of citrus, where feeding causes fruit drop and internal drying. In home gardens it is sometimes confused with green vegetable bug but is distinguished by its prominent sharp spines on either side of the pronotum. It will occasionally feed on tomatoes and other solanaceous vegetables growing near citrus.
How to identify
- Adult: 15-20mm, bright green, with pair of sharp outward-pointing spines on the shoulders of the pronotum
- Nymphs: green with red and black markings, also with shoulder spines
- Damage: fruit drop in citrus, sunken feeding spots on tomato fruit
Life cycle
Egg rafts laid on leaves. Nymphs pass through five instars over 6-8 weeks. Adults overwinter in sheltered sites. 1-2 generations per year.
Weather triggers
- Temperature: 15-32°C
- Activity peaks in warmer months. Adults overwinter and emerge as temperatures rise.
Peak season (southern hemisphere)
Red = active season · Dark red outlined = this month
Affected vegetables & crops
Click any crop to see current prices and growing info.
Climate zones at risk
Organic & low-impact control
- Handpicking adults and nymphs (wear gloves — defensive spray stains skin)
- Crushing egg rafts
- Maintain parasitoid populations by avoiding broad-spectrum insecticides
Chemical control
- Generally not warranted in home gardens
Always read product labels — registrations change.
Prevention
- Inspect citrus trees twice weekly in spring and summer
- Keep beneath-tree weed growth trimmed (sheltering habitat)
Companion planting
Flowering insectary plants support parasitoids.
Biosecurity
Native. No quarantine concerns.
Sources
- NSW DPI — Spined citrus bug
- Queensland DAF — Spined citrus bug in citrus
Accuracy confidence: medium. We update this library as new extension guidance is published.