Post-border detection of plant pests improved

HRSS surveyor
HRSS surveyor carries out
a close inspection of
vegetation during the survey.

As part of a national early warning surveillance programme for exotic plant pests, Biosecurity New Zealand (BNZ) conducts pest inspections in identified high-risk sites around New Zealand. The high-risk site surveillance (HRSS) programme undertakes phytosanitary (plant health) surveys in areas that are at increased risk of introduction of pests. Typically, these are pest pathways such as ports and transitional facilities.1

A new methodology and increased funding introduced in 2005 have increased the rate of significant plant pests detected, reversing a previous trend towards fewer detections recorded.

Programme goals

The primary goal of the HRSS programme is to provide effective detections of plant pests that have potentially adverse effects on the environment, economy or people of New Zealand. To be characterised as 'effective', the detection of a pest species

(e.g., an exotic insect or pathogen) will happen at a stage where:

  • the maximum range of management options is available; and
  • the possibility of eradication is maximised, while economic and social impacts are minimised.

The programme also monitors changes in plant pest hosts and distributions. These secondary detections constitute an important goal of the surveillance effort and are necessary for BNZ to meet international reporting requirements.

First year results

High-risk site surveillance plant pest detections, 2002 - 2006
High-risk site surveillance plant pest detections, 2002 - 2006

In response to the introduction of the revamped HRSS programme in 2005, there has been an increase in significant finds. This has offset a trend towards reducing numbers of finds over the previous three years. Figure 1 demonstrates this by totalling the number of pests found in each category during the surveillance season.

Field work

The field work is carried out by surveyors from Target Pest and Forest Health Dynamics who are contracted to AgriQuality Limited. To support the programme, AgriQuality maintains a database and geographic information system which captures vegetation species surveyed and inspection details.

In the field, close physical inspections of vegetation in transects, set up in and around the identified high-risk sites, form the core survey method. Time is allocated to extensive and discretionary phases to provide flexibility. Diagnostics of suspect samples from tree species is contracted to Ensis, with BNZ's Investigation and Diagnostic Centres (IDC) covering the remaining species.

While the surveyors are very experienced (an average of over 20 years of experience in biosecurity plant health), AgriQuality has worked with Forest Industries Training and Education Council (FITEC) to produce a Unit Standard (NZQA Standard 22984 – Carry out high-risk site surveillance in the urban forest environment) to ensure that surveyors can maintain and enhance their skills.

The HRSS contractors work with landowners and councils to ensure good coverage of risk sites around the country, and identify any areas of plant decline which may indicate a potential new pest presence. A recent workshop for the surveyors involved a 'Bio-Blitz' in the Auckland Botanic Gardens using the HRSS methodology, and a large number of pest samples were taken.

1 Transitional facilities hold, inspect, treat or destroy and dispose of uncleared risk goods imported into New Zealand. They operate under a standard which details the minimum requirements for approval and monitoring of transitional facilities functions.

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Page last updated: 30 April 2008