CHILLI THRIP - revised 2026

Apr 7
2 min read

The following is an article produced by the WA Rose Society to encourage people to persevere with growing roses in WA. Many gardeners have removed roses in the hope that Chilli Thrip will disappear. Unfortunately, they don't just live on roses, they also attack many of the plants in our gardens, including veggies and fruit!

Why Summer Is Hard on Roses

The extreme heat in Perth during Summer can cause your roses to suffer. The below information is provided as a guide to help during our hot weather.

What Is Chilli Thrip?

Chilli thrips (Scirtothrips dorsalis) are tiny, invasive, sap-sucking insects that are significant pests of various fruits, vegetables (like strawberries, tomatoes, grapes, citrus, capsicum, chilli), ornamentals (like roses, gerberas). Chilli Thrip has been in Australia for around 25 years and it is now a major problem in Perth. They are prevalent in many hot dry climates in the world. There is currently no eradiation method for Chilli Thrip, but it can be controlled.

The Good News

You CAN control Chilli Thrip. With good summer care and the right approach, your roses (and other plants) will survive the heat and reward you with beautiful blooms again.

How to Control Chilli Thrip

Keep roses healthy.
Fertilise regularly and mulch.
Water deeply and consistently
Overhead watering in the heat of the day, washes insects off the plant; increases humidity around the foliage; cools and hydrates the plant and reduces heat stress
Apply a soil wetting agent in Spring and Autumn
DO NOT prune roses hard during summer or autumn. As this allows the Chilli Thrip to enter the plant via the open cut, only light prune if absolutely necessary.
Spraying (General Guidelines).
- Spray as late in the afternoon as possible
- Always follow manufactures’ guidelines, we recommend you do not use the same product continuously as Chilli Thrip develop resistance. Spray thoroughly, including surrounding soil.
Commonly Used Products – Spraying
- Yates Success Ultra – 10ml per 1L water (repeat after 7–10 days)
- Success Neo – 4ml per 10L water (specialist product)
- Spectrum 200SC – 10ml per 10L water
- Conguard – 20ml per 3L water (double strength)
Commonly Used Products - Granular (applied around the drip line and watered in)
- Richgro Bug Killer
- David Grays Systemic Bug Killer
- Wetta Soll by David Grays or Richgro
The Organic Way: For gardeners who prefer not to use chemicals, beneficial predator insects are available. Suppliers include:
- Swiss Rose Garden Nursery (Baldivis): https://swissrosegarden.com.au/
- Biological Services: https://biologicalservices.com.au/pests/chillie-thrips/