Biological Control Strategy
Overview
Successful biological control is not simply about releasing beneficial insects. The most successful programmes combine monitoring, environmental management, preventative introductions and curative interventions into a complete Integrated Pest Management (IPM) strategy.
Modern biological control works best when beneficial organisms are introduced before pest populations become established and when crop conditions support their activity.
The Four Pillars of Successful Biocontrol
1. Correct Pest Identification
Before introducing any beneficial organism, the pest must be identified correctly.
Different beneficials target different pests:
- Thrips require different solutions to aphids.
- Whitefly requires different solutions to spider mites.
- Soil pests require different solutions to foliar pests.
Misidentification is one of the most common reasons biological programmes fail.
2. Early Intervention
Most beneficial organisms perform best when introduced early.
A small pest population is far easier to manage than an established infestation.
Examples include:
- Amblyseius swirskii before thrips become visible.
- Encarsia formosa at first whitefly detection.
- Aphidius colemani when the first aphids are found.
3. Environmental Management
Beneficial insects are living organisms and are affected by climate.
Factors influencing performance include:
- Temperature
- Humidity
- Light levels
- Crop structure
- Air movement
For example:
- Phytoseiulus performs best in humid conditions.
- Swirskii performs best in warmer crops.
- Orius establishment improves under good light conditions.
4. Monitoring
Regular crop inspections remain essential.
Monitoring allows growers to:
- Detect pests early.
- Confirm establishment.
- Identify hotspots.
- Assess programme success.
Biological control should always be supported by structured crop scouting.
Preventative vs Curative Biological Control
Preventative Strategy
Preventative beneficials are introduced before pest populations become damaging.
Examples:
- Amblyseius swirskii
- Amblyseius cucumeris
- Encarsia formosa
- Stratiolaelaps scimitus
Advantages:
- Lower pest pressure.
- Better establishment.
- Reduced crop damage.
Curative Strategy
Curative beneficials are used when pests are already present.
Examples:
- Phytoseiulus persimilis
- Chrysoperla carnea
- Adalia bipunctata
- Steinernema feltiae
Advantages:
- Faster visible impact.
- Strong hotspot control.
Most successful programmes combine both approaches.
Predators vs Parasitoids
Predators
Predators consume multiple prey throughout their lives.
Examples:
- Orius spp.
- Phytoseiulus persimilis
- Adalia bipunctata
- Chrysoperla carnea
Parasitoids
Parasitoids develop within a host insect and ultimately kill it.
Examples:
- Aphidius colemani
- Aphidius ervi
- Encarsia formosa
- Diglyphus isaea
Both groups play important roles in IPM programmes.
Layered Biological Control
Many growers achieve the best results by combining beneficial organisms.
Examples include:
Thrips
- Amblyseius swirskii
- Orius spp.
Whitefly
- Encarsia formosa
- Eretmocerus eremicus
- Macrolophus pygmaeus
Aphids
- Aphidius colemani
- Aphidius ervi
- Adalia bipunctata
Sciarid Fly
- Steinernema feltiae
- Stratiolaelaps scimitus
- Atheta coriaria
Different beneficials attack different life stages, creating more reliable control.
Common Reasons Biocontrol Fails
Late Introductions
Pests become established before beneficials are released.
Incorrect Species Selection
The chosen beneficial does not target the pest effectively.
Environmental Conditions
Temperature or humidity may be unsuitable.
Poor Monitoring
Problems are detected too late.
Incompatible Pesticides
Chemical residues can reduce beneficial survival and establishment.
Building a Sustainable Programme
The most successful growers view biological control as a crop-management system rather than a product.
Key principles include:
- Prevention over reaction.
- Regular monitoring.
- Environmental optimisation.
- Layered beneficial programmes.
- Continuous improvement.
Related Resources
- Beneficials Hub
- Predatory Mites
- Parasitoid Wasps
- Biocontrol Tool
- Release Planner
- Risk Engine
- Crop IPM Modules