Plant Doctor Archive

Buying beneficial bugs

I've heard that you can buy good bugs to control bad bugs. Can you tell me what they are and where I can buy them from?

Since the early seventies there's been a move away from pesticides into biological control.

Biological control means reducing your pest population by employing their natural predators, and these days you can buy some of these great little insects off the shelf.  

Most people don't like spraying noxious chemicals, and people certainly don't like eating them. So putting a good bug into an environment to kill the bad bugs is a simple solution to a long-standing problem.

Bio Force, in Karaka, breeds predators and parasites in glasshouses to sell to commercial growers and the public. Their biggest seller is the encarsia, a parasitoid that kills whitefly.

The encarsia parasitises the juveniles. They lay their eggs into the juveniles, and the juveniles turn black with a wasp in it.

Bio Force harvests the wasps, sticks them on a tag and sells them. The tags can then be planted on tomatoes or other plants to kill the whitefly.

This is just one of a number of parasites and predators that are commercially available.

Another small wasp lays its egg inside a live host, in this case an aphid. The parasitic wasp curls the egg-laying tube under her body to deposit an egg inside the aphid.

Also available is the reddish mite — a very active predator mite which just loves to eat the two-spotted spider mite.

Home gardeners with a pest problem must first identify their culprit before they can employ a biological enemy for control. Your beneficials need really good conditions in order to thrive — Bio Force has that information available.  

The problem is, when people use pesticides to kill the bugs, they kill the beneficials, which are twice as susceptible to the poison.

For more information, contact:

Bio Force Ltd, Tel: 09-294-8973, Fax: 09-294-8978

Advice by Dr Dan Blanchon from Unitec's Diploma in Sustainable Horticulture and Bachelor of Resource Management.

Reproduced with permission from NZOOM Home and Garden content, from the previous website of  The views expressed here are not necessarily those of the RNZIH   HOME AND GARDEN   Plant Doctor Archives Main Page