Pests and Diseases

Pests and diseases threaten New Zealand’s economy, environment, and way of life. New Zealand is fortunate to be free of many pests and diseases of humans, animals and plants due to our geographic isolation. However this also means that our population is more susceptible to incursions of new diseases, having not had the chance to develop immunity. New Zealand’s isolation and small number of points of entry to the country are to our advantage, providing opportunities to manage the border effectively and keep pests and diseases out. Surveillance programmes are designed to detect new incursions or spread of known populations as soon as possible to preserve options for responding.
Diseases of humans not found in New Zealand include vector borne diseases such as Ross River fever and Japanese encephalitis. Fortunately many of the dangerous vector species (eg exotic mosquitoes, Culicoides) and the diseases they carry are not present in New Zealand. Other diseases such as pandemic influenza viruses and bacterial diseases such as multi-drug resistant Tb and rabies have not had significant impacts on New Zealand’s population to date.
Many diseases of animals also affect humans, for example avian influenza, mad cow disease, rabies and Nipah virus. Animals can also be affected by vector borne diseases. Diseases of animals, such as foot and mouth disease and Newcastle disease of poultry, can have a significant impact on productivity and ability to export animal products. Diseases of plants, such as pine pitch canker, also impact on productivity and exports.
Pests of plants and animals also threaten New Zealand’s economy and environment. An incursion of Mediterranean fruit fly would affect horticultural industries, damaging export crops and trade in horticultural exports. The Varroa bee mite has affected commercial and hobby beekeepers, wild bee populations, and industries reliant upon bees to pollinate crops. Screw-worm fly or cattle tick (Rhipicephalus microplus) would impact on cattle industries causing hide damage, reducing productivity, and carrying diseases such as babesiosis. The Northern Pacific sea star would impact on the aquaculture industry.
Pests and diseases also threaten New Zealand’s flora and fauna. An incursion of highly pathogenic avian influenza could affect our native birds. Invasive species such as Red Imported Fire Ants have the potential to alter ecosystems, our way of life (picnics outside can be ruined by these pests), and are a nuisance to farmed livestock. Incursions of invasive species such as ants on land and the Asian clam in the marine environment can also displace and threaten New Zealand native and endemic species.

Dr Andrea Murray

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