Biological Control For Insects & Pests In A Greenhouse

Biological Control is the use of one organism (beneficial) to control another (pest). Often used to refer to beneficial insects such as wasps, bugs or mites that are used to control such pests as white flies, thrips or aphids. This term can also apply to parasitic bacteria, fungi and nematodes . *Note that there are at least 72 species of predators/parasites for 60 pest species.
Many growers, especially greenhouse hydroponic growers worldwide, began returning to biological control due to:the development of pesticide resistant pest populations

• the high cost of pesticides

• the difficulty in observing “harvest restrictions”, the delay time between application of pesticide and harvest

• the reduction in yields due to phytotoxicity of the pesticides

• the fact that DDT and other chemical pesticides were persistent in the environment and affected other species than those intended (i.e., DDT which caused thinning and brittleness of the eggs of the California Condor, death of the chicks, and decreased populations almost to the point of extinction)

• the increased concern with exposure of greenhouse workers to pesticides and, for the consumer, of exposure to pesticide residues on the produce

• the use of bumble bees in the greenhouse to pollinate the crop, especially tomatoes and peppers (see Chapter 6). Pesticides would not only kill the pest but the bees as well!

• the fact that vegetables produced “pesticide free” command a higher price at the market!

Releasing beneficial bugs on plants to control harmfull insects