What is a priority pest?
Priority pests are a significant environmental concern that have either not yet established in our region, or not widely established and have the potential to cause great harm in Otago.
These are pests that we really want to hear about, so if you see one of them, or something you think might be one of these pests, please let us know.
Report these pests!
If you have seen or suspect the presence of these pests we need to know. Please report any you see.
African feather grass
A tussocky grass that forms thick clumps up to 2m high. | Exclusion. Report this pest!
African love grass
Grows as clumps of grass up to 1.5m tall with small white flowers and black-olive/purple seeds. | Progressive containment. Report this pest!
Chilean needle grass
Chilean needle grass is a tough, tufted grass that grows up to 1 m tall. It forms dense patches and spreads sharp, barbed seeds that stick to animals, clothing, and vehicles. The seeds can cause painful injuries and even blindness in livestock | Exclusion. Report this pest!
False tamarisk
False tamarisk is a shrub up to 1.5 m tall with upright branches and small, bluish-green, narrowly triangular leaves. In summer (January–March), it produces small pink flowers in hanging clusters, followed by grey seed capsules | Exclusion. Report this pest!
Giant Hogweed
Giant hogweed is a very tall toxic plant with white flowers and purple-spotted stems. Its sap can cause burns, blisters, and even blindness | Organism of interest. Report this pest!
Great willowherb
Great willowherb is a tall, pink-flowering plant that grows up to 2 m in damp places like wetlands, riverbanks, and ditches. It forms thick stands that squeeze out native plants, change water flow, and spread by seed, wind, water, machinery, shoes—and even underground roots | Unwanted organism. Report this pest!
Japanese knotweed
Japanese knotweed is a fast-spreading weed, that can grow from pieces of root or stem. It quickly takes over an area, pushing out native plants and even damaging things like roads, walls, and buildings | Organism of interest. Report this pest!
Moth plant
Moth plant is a fast-growing climbing vine that can reach over 5 m tall. It smothers shrubs, small trees, and native seedlings, harming biodiversity. Crush its stems or fruits and it oozes a caustic milky sap that can irritate skin and is poisonous to people | Exclusion. Report this pest!
Nassella tussock
Nassella tussock is a perennial grass that grows up to 1.5 meters tall, with long, fine leaves and distinctive fluffy seed heads | Progressive containment,
Purple loosestrife
Purple loosestrife is a tall wetland weed with purple flower spikes that outcompetes natives, and blocks waterways. A single plant can produce up to 2.5 million seeds a year, spread by wind, water, and machinery | Unwanted organism. Report this pest!
Spartina
Spartina is an invasive estuary grass that forms thick clumps, traps sediment, raises flood risk, and alters bird habitats | Progressive containment
Spiny broom
Spiny broom is a sharp, invasive shrub with yellow flowers and flat seed pods that quickly takes over farmland and native areas | Eradication
Wild ginger
Wild ginger forms dense clumps that smother native bush and stop new plants from growing. It spreads quickly and is hard to remove | Organism of interest
Wilding conifers
Wilding conifers are invasive pine and fir trees spreading into tussock and farmland, reducing grazing land and increasing fire risk | Progressive containment
Yellow Flag Iris
Yellow Flag Iris is poisonous to humans and animals. It grows up to 1.5 meters tall, with broad, flat, sword-shaped leaves, and bright yellow flowers | Unwanted organism
Rooks
Rooks are large, glossy black birds with pale beaks and loud “kaah” calls. They often gather in flocks, fly up to 20 km daily, and damage farmland by eating grain and seeds. There are fewer than 40 left in Otago, and the council is working to eliminate them | Eradication. Report this!
Bennett's wallaby
Bennett’s wallaby have a greyish-brown upper body, pale grey chest and belly, and reddish-brown colour on the shoulders. They're up to 80cm high with a tail length around 62cm | Eradication & Site-led
Asian paddle crab
Asian paddle crabs have a 12 cm shell, paddle-like hind legs, and spines on their claws and shell, with colours ranging from pale-green to chestnut-brown; they inhabit estuaries and coastal zones | Unwanted organism
Clubbed tunicate
Styela clava, or clubbed tunicate, is a long, club-shaped marine animal that can grow up to 160 mm, featuring a knobbly surface, two siphons on top, and is typically found attached to various structures in shallow waters | Unwanted organism
Exotic caulerpa
Exotic caulerpa has green, oar blade-shaped fronds up to 10 cm long, growing from horizontal stems that form dense mats on the seafloor | Unwanted organism
Mediterranean fanworm
The Mediterranean fanworm is a tube-dwelling worm with a leathery appearance, growing up to 80 cm and featuring a large spiral of colourful feeding tentacles | Unwanted organism
Undaria
Undaria is an invasive seaweed that grows 1 to 2 meters long. It has a crinkly texture and comes in brown, green, and yellow colours, with a noticeable midrib and a spiral structure at the base. | Unwanted Organism
Spartina
Spartina is an invasive estuary grass that forms thick clumps, traps sediment, raises flood risk, and alters bird habitats | Progressive containment
Egeria
Egeria is a fast-growing freshwater weed that forms dense underwater meadows, blocks waterways, and harms aquatic life | Exclusion
Freshwater gold clam
Freshwater gold clam is a tiny invasive clam that clogs waterways, threatens native species, and spreads via boats | Unwanted organism
Lagarosiphon
Lagarosiphon is a fast growing, invasive aquatic weed that forms dense mats that choke waterways and harm ecosystems | Site-led
Hornwort
Hornwort is an invasive underwater weed that forms thick mats, and blocks waterways. New plants grow from broken stem fragments spread by boats, trailers, and gear | Exclusion
Purple loosestrife
Purple loosestrife is a tall wetland weed with purple flower spikes that outcompetes natives, and blocks waterways. A single plant can produce up to 2.5 million seeds a year, spread by wind, water, and machinery | Unwanted organism. Report this pest!
Spartina
Spartina is an invasive estuary grass that forms thick clumps, traps sediment, raises flood risk, and alters bird habitats | Progressive containment
Toxic algae
Toxic algae in rivers form brown or black mats, while in lakes they make the water look murky or like "pea soup" with green scums on the surface. Both are harmful to humans and animals | Monitored
Yellow Flag Iris
Yellow Flag Iris is poisonous to humans and animals. It grows up to 1.5 meters tall, with broad, flat, sword-shaped leaves, and bright yellow flowers | Unwanted organism
