Family: Cactaceae

Status: Declared noxious in all south coast LGA’s in category W4f (cannot be sold or propagated, and landowners must implement biological or other control program as directed by the Local Control Authority).

Description:
Both are cacti, with swollen fleshy stems, spines and no leaves. Common pear has flat plate-like stems and clusters of brown hairs located at raised "eyes". There may or may not also be spines from 1-5cm long emerging from these "eyes". Tiger pear stems are sausage-shaped and sized, with very long sharp spines. They both form spreading clumps to about 1m high.

Preferred habitat and impacts:
Originally garden plants, they may occur close to old buildings, but can also be spread far from habitation. Rocky slopes and river banks are favoured habitats.
Dense infestations can impede movement. The long sharp spines of tiger pear make walking through outbreaks of this plant very unpleasant. Prickly pears can dominate the vegetation of rocky outcrops displacing natives, some of which may be restricted to such outcrops, and consequently be relatively rare.

Dispersal:
Birds and other animals can spread the seed of common pear. Tiger pear fortunately does not produce viable seed in Australia.
The segments will take root from the "eyes" if left in contact with the ground, and because they are so succulent, they remain capable of rooting for several months after being detached from the parent plant. They can be moved in floods leading to infestations along river banks. The spines of tiger pear have a slight hook at the tip which will attach to animals, vehicles and humans.

Look-alikes:
The spineless Indian fig (O. ficus-indica), sometimes grown as a hedge or for its edible fruits, has also become weedy in Victoria. It may be a large shrub or develop a woody trunk and become tree-like. Its segments are very similar to those of common pear. The "eyes" on its segments are small and distant and do not contain any spines.

Control:
Plants can be dug out, but need to be disposed of very carefully because of their ability to take root again if left on the ground. Segments will remain viable even if hung up in vegetation or placed on rocks away from soil, and they may be relocated onto soil by wind, water or animals. Deep burial or burning is safest, although a lot of wood is required to consume the succulent stems. Be very careful when handling any prickly pears, as the spines easily get into the flesh and break off, causing irritation. Wear leather gloves and thick clothing and shoes. Kitchen tongs are useful for handling the smaller tiger pear segments.
Spraying with woody weed specific herbicide can be effective, but a high concentration is needed.
Biological controls (the Cactoblastis moth, or cochineal insects) are effective in warmer climates, but in southern areas they need to be reintroduced after winter. They may weaken plants and prevent seeding, but will not eradicate infestations.