Encouraging Beneficial Insects
Overview
Beneficial insects do not appear by accident. Successful Integrated Pest Management (IPM) programmes create environments that support predators, parasitoids and pollinators throughout the year.
Encouraging beneficial insects is not about eliminating pests completely. It is about improving ecological stability, increasing natural suppression and reducing the likelihood of severe pest outbreaks.
Why Biodiversity Matters
Greater biodiversity creates a more resilient growing system.
Benefits include:
- Increased predator diversity
- Improved parasitoid establishment
- Alternative food sources
- Better pollinator support
- Reduced risk of pest population explosions
- Improved ecosystem stability
Biodiversity should be viewed as a risk-management tool rather than a replacement for crop monitoring or biological control programmes.
Top 10 Principles
- Provide flowers throughout the season.
- Maintain habitat diversity.
- Reduce unnecessary insecticide use.
- Encourage alternative prey populations.
- Provide overwintering sites.
- Reduce large areas of bare ground.
- Maintain suitable field margins where practical.
- Create continuity of food resources.
- Improve soil health.
- Think beyond the crop and consider the wider landscape.
Flower Resources
Many adult beneficial insects require nectar and pollen.
Useful plants include:
- Sweet Alyssum
- Phacelia
- Buckwheat
- Yarrow
- Dill
- Fennel
- Calendula
- Cosmos
- Clover
- Coriander
Different flowering periods help provide season-long resources.
Habitat Resources
Beneficial insects require more than flowers.
Important habitats include:
Ground Layer
- Mulch
- Leaf litter
- Cover crops
- Beetle banks
Supports:
- Ground beetles
- Rove beetles
- Spiders
Shrub Layer
- Hedgerows
- Shelter belts
- Mixed perennial planting
Supports:
- Hoverflies
- Parasitoids
- Lacewings
Flower Layer
Supports:
- Hoverflies
- Parasitoid wasps
- Predatory bugs
- Pollinators
Alternative Prey
Alternative prey can help beneficial populations survive when target pests are scarce.
Examples include:
- Non-damaging aphid species
- Pollen-feeding systems
- Banker plant systems
Maintaining low-level prey populations may improve predator continuity and reduce establishment delays.
Biodiversity In Protected Crops
Biodiversity can also be encouraged in glasshouses and tunnels.
Examples include:
- Banker plants
- Alyssum strips
- Flowering refuge plants
- Managed pollen sources
- Reservoir plants for beneficial insects
These approaches may improve establishment of predators and parasitoids.
Biodiversity Risks
Biodiversity is not risk-free.
Potential risks include:
- Pest reservoirs
- Disease reservoirs
- Weed management challenges
- Increased monitoring requirements
The objective is management, not uncontrolled diversification.
Key Message
The most successful IPM programmes do not rely on a single beneficial insect.
They create conditions where beneficial organisms can survive, establish and respond to pest pressure over time.
Long-term system stability is usually more valuable than short-term pest suppression.
Related Resources
- Biological Control & IPM Foundations
- Biological Control Strategy
- Beneficials Hub
- Environmental Drivers Hub