Biocontrol agents

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NGINZ and Landcare’s biocontrol team meets on a regular basis.  The latter is usually contracted by regional councils to investigate and develop applications to the EPA for the importation and/or release of biocontrol agents for the control of invasive weeds.   NGINZ’s role is to seek assurance of robust consideration of the risks to any unintentional effects for native and/or ornamental flora which are closely related to the target weed species, and for which the biocontrol agent may have a liking - so called off-target-host effects. 

Off-target-host effects are most often mitigated by the specificity of the biocontrol agents feeding habits – one of the cornerstones of the programme.

While working with Landcare during the early development stages, NGINZ reserves the right to support or not any specific application, or part therof, during EPA's consideration.

Read more about biocontrol on Landcare's website


Biocontrol agent for Arundo - the gaint reed


The EPA is seeking submissions on or before 3 November on an application to introduce a gall forming wasp (Tetramesa romana) and a scale insect (Rhizaspidiotus donacis) to control giant reed (Arundo donax), You may either make a submission directly to the EPA or send yours through to NZPPI - john@nzppi.co.nz

You may either make a submission directly to MPI or send yours through to NZPPI - john@nzppi.co.nz

NGINZ submissions lodged


This month NGINZ lodged submissions or provide feedback on:

  • An application to release a moth and leaf beetle as biological control agents for the weed tutsan. While supportive in that no direct impact is foreseen for nursery production or home garden ornaments, we made note of possible spill-over effects into native hypericums.
  • Further EPA scrutiny on a set of organophosphates.
  • The introduction of weevil to control Field Horsetail - which we supported.
  • The release from containment of a parasitoid wasp to control of the tomato potato psyllid - which we supported.
  • Additionally Landcare have sought our review of work (from an off-target host range testing point of view) on biocontrol options for Gaint Reed.

Landcare's biocontrol work update


October’s meeting discussed Landcare work for seven weed species with some issues being identified for landcare followup:

  • Privet (Ligustrum) and the release of the privet lace bug - the project needs to better understand the impact, or not, on ornamental lilac.
  • Japanese honeysuckle (Lonicera japonica) and the importation of the honeysuckle longhorn beetle - the planned off target host testing for viburnum, weigela and others is robust
  • Moth plant and the release of a moth plant rust - potential impact on tweedia and swan plants needs to be assessed.
  • Lagarasiphon (a freshwater weed) and the importation of a leaf mining fly - no issues identified for the nursery and garden industry
  • Field horsetail (Equisetum) and the trialing of a root weevil - little impact is envisaged
  • Ginger and the use of a stem-mining fly or ginger weevil - care need to be exercised over potential impact on other Musa and Myoga
  • Old man's beard and the use of a leaf curling mite - potential impact on native and exotic clematis needs to be thoroughly investigated.