Biological Pest Controls

Overview of the progress of biological controls of weed species across the Shoalhaven and Illawarra

Biological Pest Controls

Overview of the progress of biological controls of weed species across the Shoalhaven and Illawarra

Taking Action -


The issue

Weeds and pests grow and reproduce faster that we can control them. That’s both the problem, and why we are losing the battle. Biological controls – rusts, viruses and insects – have the potential to change the balance, but they are variable in their impact, unreliable and unpredictable and viewed with suspicion by many landowners.  Everyone remembers the cane toad, but few recall cactoblastis.  Government interest is variable, dampened by inconsistent outcomes and often varying with funding cycles. It was a struggle to maintain enthusiasm over the years through the ups and downs.

The solution

Landcare groups in the Shoalhaven have embraced all opportunities to be involved in the promotion, distribution and monitoring of 8 biological control agents over the past 15 years. This involved keeping in regular contact with the experts in CSIRO, DPI and Local Government, seeking updates and offering assistance. As agents became available for release, Landcare and Bushcare groups and active landowners have embraced the opportunity and participated as the willing arms and legs on the ground.  Over the past 15 years, we have been involved with releases and monitoring of biocontrol agents to control Mist Flower, Crofton Weed, Lantana, Madeira vine, Bitou Bush, Bridal Creeper, Giant Parramatta Grass and wild rabbits.

The impact

Results have been valuable yet variable... 

  • Rusts for Mist Flower and Crofton Weed have spread rapidly, without assistance and have persisted in the landscape to allow for replacement by native ferns, herbs and grasses.
  • In coastal areas, Bushcare groups have led the fight with effective controls against Bitou Bush and Bridal Creeper.
  • Giant Parramatta Grass is a major threat to our grazing industries. Unfortunately crown rot fungus has not persisted in our climatic conditions however trials and monitoring involving Landcare are continuing and we remain hopeful.

The CSIRO provided Landcarers an insightful and positive briefing on new biological controls under development and future funding at a forum at Berry in August 2017.

Key facts

  • CSIRO updated Landcarers on status of bio-controls in Berry August 2017
  • Results are variable with some successes and some challenges
  • Inconsistent and irregular funding further limits progress

Project Partners