On 8 November the Environmental Risk Management Authority (ERMA New Zealand) formally approved a first of a kind decision to conditionally release a tiny parasitic Irish wasp (2-3 mm long and not harmful to humans). The wasp has been tested as a biological control agent for clover root weevil through research carried out by Dr Pip Gerard of AgResearch. There will be a period of time for the tiny wasp to establish itself and impacts on the clover root weevil may be observed later.

Clover root weevil is considered a significant pest of clover which is a vital component of New Zealand's pastoral economy. Dr Pip Gerard and submitters consider that clover root weevil threatens the sustainable production of clover in New Zealand which is estimated to have an annual value of $3 billion.

‘There is great excitement about this first use of a conditional release', says the chair of the decision making committee Dr Max Suckling, ‘The conditional release criteria were introduced into the Hazardous Substances and New Organisms Act in response to recommendations made after the Royal Commission on Genetic Modification. Conditional release is a category of application designed to enable controls to be put on release applications. In this instance the application is for a new organism being released to the environment and controls are being used to make sure that only strains of the wasp that can not hybridise with another strain are released.'

A Moroccan strain of this small parasitic wasp has been present in New Zealand since 1982 when it was introduced as a means of controlling Lucerne weevil. All other strains of the wasp have been declared ‘risk species' under law because of concerns that the introduction of different strains may result in hybridisation and stop them from being effective at controlling the weevils they were introduced to control. The Irish strain of the wasp is parthenogenic which means that it is incapable of hybridisation because it reproduces without fertilisation. The decision making committee took this into account and introduced a condition that only parthenogenic individuals could be released.

‘We have to be very careful to take all risks, costs and benefits into account when we are making decisions and this includes information gained through public submissions and consultation with iwi groups.' said Dr Max Suckling

Decision document in PDF format: http://www.ermanz.govt.nz/appfiles/execsumm/word/NOR05001-007.doc