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
- 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
The mistflower gall fly (Procecidochares alani): this was approved to control mistflower (a serious weed in conservation areas in Northland) in November 2000.
The hieracium gall fly (Macrolabis pilosellae), the root-feeding hover fly (Cheilosia urbana) and the crown-feeding hover fly (C. psilophthalma): approved to control hawkweed in June 2001.
The boneseed leafroller: this was approved in February 2005 to control boneseed – a significant weed in conservation areas.
The buddleia leaf weevil: approved to control the weed pest buddleia (a weed of forestry plantations) in November 2005.
The ragwort crown borer (Cochylis atricapitana) and the ragwort plume moth (Platyptilia isodactyla): approved to control ragwort (a serious weed affecting pastoral farming) in December 2005.
The mite (Aceria genistae), the broom shoot moth (Agonopterix assimilella) and broom leaf beetle (Gonioctena olivacea): were approved to control the weed broom in July 2006.
A beetle (Cassida rubiginosa) and a weevil (Ceratapion onopordi): these were approved in April 2017 to control the weed Californian thistle.
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.
Two rust fungi Puccinia lantanae and Prospodium tubuculatum, were approved to control the weed Lantana camara in April 2012.
Two weevils, Anthonomus kuscheli and Berberidicola exaratus were approved to control the weed Darwin's barberry (Berberis darwinii) in October 2014.
Privet lace bug (Leptophya hospita) was approved as a biological control agent for the weed privet (Ligustrum spp.) in May 2015.
The Honshu white admiral butterfly (Limenitis glorifica) was approved to control the weed Japanese honeysuckle (Lonicera japonica) in August 2013. The honeysuckle stem-boring beetle (Oberea shirahatai) was approved for release in July 2015.
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.
Two agents were approved for the biological control of tutsan, a moth (Lathronympha strigana) and a beetle (Chrysolina abchasica) in May 2016.
The arundo galling wasp (Tetramesa romana) and the arundo scale insect (Rhizaspidiotus donacis) were approved for the control of giant reed (Arundo donax) in January 2017.
- Wheeleria spilodactylus (horehound plume moth) and Chamaesphecia mysiniformis (horehound clearwing moth) were approved for the biocontrol of horehound (Marrubium vulgare) in September 2016.
- A mite, Aceria vitalbae, was approved for the biological control of Old man's beard (Clematis vitalba) in October 2018.
- The beetle, Freudeita cf cupripennis, was approved for the biological control of the noxious weed, moth plant (Araujia hortorum) in May 2019.