biological control

The release of one kind of organism to reduce the population of another, typically by preying on them, parasitizing them or causing disease. To control pests, agents include predatory insects and mites, parasitic wasps and nematodes, and the bacterium Bacillus thuringiensis which kills many insect larvae. Agents to control fungi include a fungus antagonistic to the decay fungus Heterobasidion annosum, an uncoloured mutant of sapstain and a virus parasitic on the chestnut blight pathogen.

This definition is abridged from A – Z of tree terms: A companion to British arboriculture.
Read the preface. Order the book.