Biological Control

Biological control involves the use of a living organism to reduce a pest species to acceptable limits. In New Zealand more than 45 beneficial species of parasites and predators of pests and weeds have been successfully established. These range from ladybirds against aphids, weevils against thistles to parasitic flies and wasps against leaf roller caterpillar. A diverse living environment full with many flowering plants is required to maintain a balance to allow the populations of all species to live in harmony. Once artificial herbicides and insecticides are introduced this balance is interrupted and it then takes many years to return to its original self.