Some beneficial insects can become so numerous that gardeners may require identification, fearing that they are a new pest. There are many different species of beneficial insects and it is beyond the scope of this article to describe them all. Often a beneficial insect may attack only one pest species.
Most insecticides kill beneficial insects along with pests. Beneficial insects can be bought from suppliers to tackle unwanted pests, however, it usually takes time for beneficial insect numbers to 'catch-up' with pest outbreaks and control them.
Types of beneficial insects
There are two main groups of beneficial insects:
Predators — attack and eat other insects. Either adult or larvae, or both may be predatory.
Parasites — lay eggs on or in other insects. The eggs hatch and the developing larvae consume the host, usually from the inside.
Other beneficial insects perform many useful and important functions. For example, dung beetles bury animal droppings; weed-eating insects are being introduced to control dock, Paterson's curse, and double-gees; and bees pollinate flowers and produce honey.