Biological control uses living enemies of a pest, such as predatory insects, birds, toads and poultry, to hold its numbers down, and for a community the practical form is conservation: protect the enemies already on the land by giving them food, shelter and water and by not killing them with broad sprays. Livestock can be put to work too, with chickens cleaning beds between crops and ducks hunting slugs.
Biological control is the suppression of pests by their natural enemies and by animals managed for the purpose.
Your Best Pest Controllers Are Already There
The carrier’s starting point is that predators and parasites are already on the land, and the task is not to kill them and to give them habitat. Three routes:
- Conservation. Provide flowers, shelter and water; avoid broad poisons (Beneficial Insect Attractors).
- Larger predators. Birds, toads, frogs, bats and wasps take insects and rodents (Predator Encouragement).
- Managed livestock. Poultry and ducks, used on the right bed at the right time (Chicken Tractors for Pest Reduction, Duck Patrols for Slugs and Snails).
Releasing bought insects (a third strategy used in commercial farming) is not available without a supplier and is unreliable without habitat, so it is not the community route.
How Biological Control Differs From A Spray
A spray acts at once and wears off. A natural enemy builds slowly, follows the pest, and reproduces when there is food. That means:
- It is slow to start. The first season with new flowers may show little. Expect a few seasons.
- It never reaches zero. Enemies need a few pests to live on; the carrier’s aim is balance.
- It is destroyed by one broad spray. A single application can kill the beneficial population that took years to build.
- It works best on steady pests and poorly against a sudden outbreak. For those, use handpicking and barriers (Physical Controls).
Stored Food Is A Different Case
The Phase 2 biological control guide is about cats and other enemies of pests in stored food (Biological Control). The field-crop methods here are different animals and tools.
What You Need
- Flowers that last through the season.
- Habitat: undisturbed mulch, hedges, stone borders, water.
- Restraint: no broad-spectrum sprays, including botanical ones.
- Patience and a log of pests and enemies by season (Monitoring and Identification).
Common Mistakes
- Expecting a result in a month. The enemy follows the pest, not the reverse.
- Spraying “just once”. It resets the build-up.
- Providing no shelter. Predators with nowhere to live leave.
- Ignoring the costs of livestock. Hens eat seedlings and leave manure.
What’s Next
- Learn next: Predator Encouragement (Birds, Toads, Wasps) — the larger helpers
- Combine with: Integrated Pest Management (IPM) — where biological control fits