Weed information

• Biological control (or biocontrol for short) uses one living organism (a natural enemy) to control another living organism (a weed).
• The most commonly used natural enemies are insects (herbivores such as leaf-eaters, seed-eaters, or root-eaters) and fungi (rob nutrients from plants, cause diseases in plants, which often results in necrosis of leaves or complete leaf loss).
• Natural enemies are introduced from the weed's country of origin and re-united with the weed in New Zealand.  After release, the breed and spread naturally. This is called classical biocontrol. Inundative biocontrol uses large amounts of native fungi to create a disease epidemic. The fungi are turned into a specific bioherbicide which can be applied (e. g. sprayed) onto weeds to control them.
• Natural enemies (or biocontrol agents) can control weeds to a point where we don't have to use any other control methods.
• Agents can attack different parts of the weed. For example, seed-eating agents can eat the seeds and stop new weed seedlings taking over when the leaf-eating agents attack and kill the mature weeds.
• Biocontrol pays for itself many times over. It's expensive at the beginning, but on-going weed control costs are free because the biocontrol agents continue to attack the plants free of charge, year after year.