What is a prickly pear?

It was a kind of cactus plant that was introduced to Australia as a popular house plant back in the late 19th century.

By the 1900’s though, the prickly pear (which some people had used for hedging) had grown out of control like a form of creeping plant and had infested over four million hectares (ten million acres).

The only way they could control it was by infesting it with caterpillars from South America.