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Biological control agent introduction regulation and the compliance rationale

From Biosecurity 100, October 2010.

In the following article AgResearch scientist and leading biocontrol researcher, Barbara Barratt, discusses this regulatory framework and its importance to New Zealand’s biosecurity.

An introduction to biological control:

Biological control can be defined as the deployment of natural enemies (predators, parasitoids or diseases) to suppress populations of pests such as insects and weeds. When pests arrive from overseas they often come without the suite of natural enemies which would normally keep them in check in their natural range. As a result they sometimes undergo periods of population outbreak before existing natural enemies adapt to them, or before pest management strategies, including biological control can be developed.  Researchers usually look for potential biological control agents in the country of origin of the pest, and select those that are likely to be safe and to succeed in New Zealand.

Biological control includes release of organisms with the intention of establishing permanent populations for pest management (classical biological control); release of organisms that cannot survive the winter in  New Zealand but that are released in high numbers to achieve control over a short period (for example glasshouse crop pests), or which are able to build up quickly in the field during the warmer seasons (augmentative biological control). Enhancement of naturally occurring organisms is known as conservation biological control.

The benefits of biological control in New Zealand:

Not all biological control programmes in New Zealand have been successful, but many are playing a critical role in keeping pests and weeds below damaging levels and contributing to reduction in the use of pesticides. In classical biological control the agents are released into the environment with the expectation that they will reproduce and disperse naturally, helping to reduce pest density and hence damage to crops or natural ecosystems in a sustainable and natural way. Other than these clear benefits, classical biological control usually involves little or no input or ongoing costs for growers or land managers, provides a long-term if not permanent contribution to pest management, and represents no health risks to producers or the public.

The earliest biological control agent introduction into New Zealand was the ladybird Coccinella undecimpunctata, a predator released in 1874 to attack aphids. Since then over 500 biological control agents have been introduced against 126 target pests (Ferguson et al. 2009). Some of the biological control successes in New Zealand have been parasitoids for weevil forage pests, several aphid species, cabbage white butterfly, Sirex wood wasp, and weed biological control agents for ragwort, St John’s wort, mist flower, nodding thistle and others.

Biological control is not usually considered to be the “silver bullet” for managing pests, but it is an important component of the suite of pest management options along with others such as plant resistance or tolerance of pests, cultivation methods, timing of sowing or harvesting to avoid weeds and pests, and strategic use of pesticides if needed.

Potential risks of biological control agents:

New Zealanders are very aware of some of the ill-considered introductions of the past such as gorse, possums and rabbits. While these were not biological control agents, examples like these have made us aware of the risks of introducing new organisms that could be environmentally, socially or economically damaging, and have served to encourage caution in our approach to deliberate introductions. The potential risks from biological control introductions can come from either direct effects on non-target species or indirect effects on the ecosystem into which the new species arrives. Direct effects include attack on species other than the target pest, which can occur especially if there are species in New Zealand that are closely related to the target pest. Depending upon how host-specific the biological control agent is species which occur in or near the habitats where the target host is found can potentially be at risk. Predatory insects that consume their prey are usually less host specific than parasitoids that have evolved to survive within the tissues of their hosts.

Indirect effects can be much more difficult to predict, but include displacement of a native natural enemy by an introduced biological control agent; hybridisation of the biological control agent with closely related native species; food web effects resulting from population changes within an ecosystem. Direct and indirect effects of proposed biological control agents clearly need to be considered on a case-by-case basis.

The purpose of the HSNO Act 1996:

The introduction of new organisms into New Zealand is regulated under the Hazardous Substances and New Organisms Act 1996 (HSNO) which is implemented by the Environmental Risk Management Authority (ERMA New Zealand) []. The HSNO Act stipulates that a cautious approach should be taken to the introduction of new organisms and a framework has been developed for a consistent process of assessment and approval of applications to import, conditionally release or release, micro-organisms, plants, and animals (ERMA New Zealand 1998). Clearly, biological control agents that are new to New Zealand are subject to the HSNO Act.

The purpose of the Act is to protect the environment, and the health and safety of people and communities by preventing or managing the adverse effects of hazardous substances and new organisms. Principles to be recognised and provided for in the legislation include safeguarding the life-supporting capacity of air, water, soil and ecosystems. In its decision-making role, ERMA New Zealand must take into account the sustainability of all native and valued introduced flora and fauna, intrinsic value of ecosystems, public health, relationship of the Maori people with the biophysical state, economic and related benefits and costs, and New Zealand’s international obligations.

One of the most important aspects of the HSNO Act that applicants need to address, in their risk analyses for biological control agents, are Section 36: “Minimum Standards”.

The Act states that the Authority must decline the application, if the new organism is likely to cause any significant: displacement of any native species within its natural habitat; deterioration of natural habitats; adverse effects on human health and safety; adverse effect to New Zealand’s inherent genetic diversity; or cause disease, be parasitic, or become a vector for human, animal, or plant disease.

As well as the HSNO Act, applicants wanting to introduce new biological control agents need to comply with the Biosecurity Act 1993. This provides rules for the exclusion, eradication, and effective management of pests and unwanted organisms in New Zealand. In the context of biological control, the Biosecurity Act is mostly concerned with the prevention of importing organisms that might be associated with the biological control agent such as parasites, pathogens and contaminant organisms. The Biosecurity Act also regulates containment facilities where imported biological control agents need to be housed once ERMA New Zealand have approved an organism for entry into containment and while efficacy, biosafety and other testing is carried out.

The risk analysis process:

Biological control researchers need to conduct a risk analysis to identify and assess as far as possible the likelihood of adverse impacts from release of the biological control agent, and the magnitude or consequences if they occur. For example, for direct effects such as attack on non-target species mentioned above, the applicant must consider how likely is it that a nontarget species will be attacked by the proposed biological control agent, and if it did occur what would be the severity of environmental or other consequences. Evidence can be based on experimental data from containment testing, information from other sources such as overseas experience with the same organism, host specificity in its native range, biosafety of related biological control agents etc. A degree of uncertainty will always remain since behaviour of an organism in a new environment cannot be completely inferred from laboratory studies and other available information, and this needs to be balanced against benefits. While ERMA New Zealand is required to adopt a precautionary approach to decision-making, it is accepted that zero risk is not possible to achieve, but that benefits should outweigh risk.

Applicants are required to prepare a cost-benefit analysis in which environmental, economic and social benefits to New Zealand are presented for ERMA New Zealand to take into account during the decision-making process. The applicant is also advised to consult fully with community groups, Maori and stakeholders. Once the applicant has submitted the application, ERMA New Zealand conducts an evaluation and review process, calls for and considers public and stakeholder submissions, often conducts hearings where evidence is presented, and then on the basis of all the evidence, make a decision.

The cost of compliance:

The current fee for an application to release a biological control agent is NZ$16,875. If the application is for a conditional release (release with controls) then this needs to be negotiated with ERMA New Zealand. The fee structure has been reduced considerably in recent years, partly to encourage compliance, and also because the process has become streamlined as a result of improved information provision by applicants, the lack of need for a public hearing for some applications, and improved efficiencies in the processing of applications by ERMA New Zealand. If extra information or expert advice is required, there can be additional costs. However, if the applicant has consulted fully with ERMA New Zealand and stakeholders during the preparation of their application, these costs can be minimised or avoided.

Risks to New Zealand of non compliance:

Having a clearly defined, transparent and consultative process and a standard methodology for regulators encourages good practice in biological control and ensures consistent consideration by experienced evaluators. In comparison with other countries, the system in New Zealand is considered to be closest to a “flawless democratic and complete process” (Sheppard et al. 2003), and is the envy of many biocontrol researchers throughout the world for the consultative nature of the relationship between applicant and regulator, and the comparatively short timeframe within which decisions are made. Given this, and the relatively modest costs currently required for processing an application, the risks associated with non-compliance are significant.

The environmental risks of noncompliance are potential risks to native and valued flora and fauna. While there will inevitably remain an element of risk in all new organism introductions, these risks can be minimised by undertaking a robust risk analysis, which is reviewed and evaluated in a transparent and consistent manner. In cases where retrospective analyses of previous biological control introductions have been carried out, experience has shown that predictions of environmental safety made after a thorough environmental impact assessment have generally been realised post-release.

Importance is placed upon the opportunity for public involvement in the process because people’s values or quality of life may be affected by the decisions taken. It is in the interests of all involved in biological control to endeavour to engage the public and stakeholders in discussion about biological control as an effective tool in pest management, to contribute to public education and generally to build confidence in this technology. So the social risks of non-compliance are alienation of the public, loss of confidence and support for science in this area, and damage to New Zealand’s reputation as a responsible custodian of our unique biota.

The economic risks of non-compliance are associated with both environmental and social risks. New Zealand trades successfully on the reputation we have for maintaining a high quality experience for eco-tourists, and similarly for the unspoiled environment from which our agricultural products are exported. Furthermore, we also have a very high profile internationally for our biosecurity system and the rigour with which we protect our productive and natural environments, and our unique heritage.


ERMA New Zealand, 1998. Annotated Methodology for the consideration of applications for hazardous substances and new organisms under the HSNO Act 1996. Pp. 28. ERMA New Zealand, Wellington, New Zealand

Ferguson, C.M., Moeed, A., Barratt, B.I.P., Hill, R.L. and Kean, J.M., 2009 BCANZ - Biological Control Agents introduced to New Zealand.

Sheppard, A.W., Hill, R.L., DeClerck-Floate, R.A., McClay, A., Olckers, T., Quimby, P.C. and Zimmermann, H.G., 2003. A global review of risk-benefit-cost analysis for the introduction of classical weed biological control agents against weeds: a crisis in the making? Biocontrol News and Information 24: 91N-108N



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