kills needles on the north island totara
- Size
- Microscopic
- Lifespan
- Indefinite (persists in soil)
- Diet
- Parasitic. Infects roots and needles of Podocarpus species. Blocks water transport causing needle blight and eventual tree death.
- Habitat
- Soil and root systems of Podocarpus species. Infects tōtara (Podocarpus totara) and other native podocarps in forests and cultivated settings.
- Range
- Described from New Zealand. Known from the North Island. May be more widespread. Distribution still being mapped by researchers.
- Endemism
- Introduced
- Main Threats
- Emerging pathogen with unknown potential for spread. No cure once soil infected. Spread by human activity including soil movement.
- Population
- Described in 2022. Emerging pathogen affecting tōtara and related species. Distribution and population unknown. May be widespread.
- Conservation Status
- data_deficient
- Human Risk
- harmless
- Handling Note
- avoid disturbing tōtara roots in known infected forest areas
- Conservation Note
- Introduced oomycete pathogen; data insufficient for classification, not subject to conservation assessment.
- Te Ao Māori
- Phytophthora podocarpi has no recognised Māori name as it was only described in 2022. Tōtara (Podocarpus totara) is a taonga (treasure) for Māori valued for its wood, its presence and its place in the forest. The emergence of a new disease threatening tōtara is of deep concern. The principle of kaitiakitanga (guardianship) demands action to protect this iconic tree.
A microscopic killer targeting one of New Zealand's most iconic trees. Phytophthora podocarpi was described in 2022 making it a recent addition to the growing list of Phytophthora diseases affecting native forests. Its common name is tōtara needle blight. It attacks tōtara, the mighty tree that gave its name to a hundred places on the map. The pathogen is an oomycete not a fungus though it looks like one. Water moulds. They swim through wet soil hunting for roots. They find a host. They infect. The tree begins to die.
Tōtara is a podocarp, an ancient conifer lineage. The leaves are needle-like, sharp, dark green. The bark is thick, fibrous, reddish-brown. The wood is durable, resistant to rot. Māori valued tōtara for carving, for building, for waka. The tree is central to the forest. The symptoms of needle blight appear in the canopy. The needles turn yellow then brown. They drop. The tree thins. It looks unhealthy. It may die within a few years. The pathogen attacks the roots blocking water transport. The tree dries out from the inside.
Phytophthora podocarpi was isolated from diseased tōtara seedlings in a nursery. Further surveys found it in forest soils. It may be widespread in the North Island. It may have been present for decades before it was named. The species name podocarpi refers to the host genus Podocarpus. The pathogen is named for the tree it kills. Simple. Direct. Accurate. Tōtara needle blight joins kauri dieback as a threat to New Zealand's iconic native trees. Both are caused by Phytophthora species. Both are spread by soil movement. Both are difficult to manage.
There is no cure. Once the soil is infected it stays infected. Management involves hygiene: cleaning boots, staying on tracks, avoiding soil movement. The same message as for kauri. The same frustration. Tōtara is a taonga, a treasure. It is central to Māori culture. Canoes were carved from tōtara. Buildings were built from tōtara. The tree is a symbol of strength and endurance. Now it is under threat. Scientists are working to understand the pathogen. Where did it come from? How does it spread? Which podocarp species are most vulnerable? The answers are not yet known. Tōtara needle blight is a reminder. The soil is not sterile. The trees are not safe. The pathogens are here and more are arriving.