Biological control agents

Biocontrol is increasingly being recognised as an essential part of integrated pest management systems that contributes to sustainable pest control.

Our role in biocontrol

We have pioneered world-leading qualitative risk assessments. These assessments analyse and weigh up environmental, economic, societal, human health, and cultural values into a decision-making framework for using new biological control agents (BCAs) in New Zealand. 

Weeds and agriculture pests

Weeds are one of the hardest to control pest problems in New Zealand with massive adverse effects on productive land, natural habitats, and taonga species. The costs to conventionally manage weeds can be significant, as well as the costs of reduced productivity and biodiversity loss.

We have approved BCA insects to control serious agriculture pests such as codling moth and the tomato potato psyllid.

The benefits of biocontrol

Biological control sustainably controls the abundance of weeds and insects in the environment. Classical biological control relies on the release of large numbers of biocontrol agents to allow insect or pathogen populations to establish. These agents continue to control target pests over many years.

The underlying principles of biocontrol are safety, self-sustainability, and cost-effectiveness. It has long-term application. Biocontrol reduces the reliance on conventional pest controls such as pesticides. Pesticides may be too expensive to control pests over widespread areas, and may have harmful indirect effects on non-target species.

Insect pest biocontrol agents approved for use in New Zealand Plus
  • A small wasp (Thripobius semiluteus) was approved to control greenhouse thrips in June 2000.
  • A wasp (Pseudaphycus maculipennis now known as Acerophagus maculipennis) was approved to control the obscure mealybug, which damages pip fruit crops, in August 2000.
  • An Irish strain of a parasitic wasp (Microctonus aethiopoides) was approved to control the clover root weevil (a significant pest of New Zealand's main pasture species) in November 2005. As this is a release with controls, this wasp strain remains a new organism.
  • Cotesia urabae was approved for the control of the gum leaf skeletoniser – a threat to eucalypt trees in July 2010.
  • The parasitoid wasp Mastrus ridens was approved to control codling moth (Cydia pomonella) in June 2012.
  • Tamarixia triozae was approved to control the tomato potato psyllid, a serious pest of solanaceous crops in New Zealand in June 2016.
  • Samurai wasp (Trissolcus japonicus) was conditionally approved to be released in August 2018. This approval can only be used by the approval holder (Brown Marmorated Stink Bug Council).
  • The parasitoid wasp Eadya daenerys was approved to control the eucalyptus tortoise beetle - a threat to eucalypt trees in February 2019.
Weed biological control agents approved for use in New Zealand Plus