Garden sentinels for biosecurity and Rapid ‘Ōhi’a Death and threat to Aotearoa New Zealand

The use of sentinel (expatriate) plants, is an initiative for plant biosecurity risk assessment and surveillance that is being adopted more widely internationally. The concept is based on the presence of plant species in foreign locations (e.g., botanic gardens, arboreta) where they may be exposed to new pests and pathogens and can act as an early warning system for a plant in its native range.

The International Plant Sentinel Network (IPSN) has been developed to facilitate collaboration between botanic gardens and arboreta, plant health organisations and scientists.

The study aimed to address the following key questions:

• What (unknown / new) pests/pathogens affect the host species of interest in selected countries outside the UK?
• Is the use of the IPSN network and (remote diagnostics) using UK diagnostic expertise feasible for a long term and wide ranging study of UK host species?

The Christchurch Botanic Gardens has been a participant in a three year pilot study to test the suitability of the sentinel plants concept to detect new host-plant associations on selected plant species considered important to the UK.