Biological control of weeds in Aotearoa/New Zealand: History, science and achievements to date

Abstract

Aotearoa / New Zealand is the leading country globally in the use of biological control agents to combat introduced pest weed species. Here we review the history of biological control in Aotearoa / New Zealand, compile a list of current, self-introduced and accidentally introduced biocontrol agents, and list the agents currently under consideration for introduction to Aotearoa / New Zealand (accurate to 2021). We discuss the science and procedures in place for the safe introduction of a new biocontrol agent and discuss the public’s perception of biological control within Aotearoa / New Zealand.

Since the 1920s there have been 79 control agents released; 68 of those species were deliberate introductions, eight self-introductions and three accidental introductions. Additionally, there have been eight reported occurrences of non-target-species attack by biological control agents in Aotearoa / New Zealand, all of which cause minor damage to their unintended hosts. Prior to their introduction to Aotearoa / New Zealand, potential biological control agents are required to undergo rigorous research and host-specificity testing to ensure that the agent does not pose a risk to indigenous taxa through non-target attack.

This research is essential, as it ensures a precautionary approach is taken prior to introductions, which, in turn, provides the wider public with confidence in the validity of biocontrol agents as a means to manage weed species in Aotearoa / New Zealand.