How do predators act as biological control ?

Explanation

How do predators act as biological control ? Ans. The prickly pears cactus introduced in Australia in the early 1920s. caused havoc by spreading rapidly into millions of hectares of rangel and (vast natural grass lands) Finally, the invasive cactus was brought under control only after a cactus-feeding predator (a moth) was introduced into the country. Biological control methods adopted in agricultural pest control are based on the ability of the predators to regulate prey populations.