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 also 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 biocontrol relies on the release of large numbers of biocontrol agents to allow establishment of insect or pathogen populations that 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 reliance on conventional pest controls such as pesticides, which may be prohibitively expensive to control pests over widespread areas and may have deleterious indirect effects on non-target species.
Insect pest biocontrol agents approved for use in New Zealand
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 triozaewas 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 daeneryswas 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
In November 2008 a beetle from Brazil (Neolema ogloblini) was approved to control the weed tradescantia[SC8] . In June 2011 two more beetles from Brazil, Neolema abbreviata and Lema basicostata, were approved to control tradescantia.
In January 2013 the yellow leaf spot fungus Kordyana sp. was also approved to control tradescantia[SC10] .
The lace bug (Gargaphia decoris) was approved to control woolly nightshade (a weed which forms dense canopies that prevent the establishment of other species) in September 2009.
The plant fungal pathogen Uromyces pencanus was approved as a biological control agent for the emerging weed Chilean needle grass in June 2011. This approval has lapsed.
Colaspis argentinensis was approved for the control of moth plant (Araujia hortorum) in December 2011. The rust fungus Puccinia araujiae was approved as the second biocontrol agent for moth plant in December 2015.
A weevil Grypus equiseti was approved to control field horsetail (Equisetum arvense) in May 2016.