Beneficial Insects in the Garden

When you’re growing a garden, it can sometimes feel like you’re just working to feed the neighborhood bugs. The reality is that your garden is a cafeteria for all kinds of insects. But, not all of them are there to feed on your veggies! Many insects actually see those pesky plant-eaters as dinner. Consider taking some steps to make sure that you are catering to the natural enemies rather than the pest insects:

• With any ecosystem, diversity is key. The more complex and diverse your garden landscape is, the more likely beneficial insects will call it 'home.'
• Include a variety of native flowering plants in and around your garden. Try to make sure that there are blooms available throughout most of the year. Many beneficial insects need pollen and nectar to survive.
• Consider adding small, shallow mud or water features around your garden. Many beneficial insects need fresh water sources to survive and will appreciate having one close by.
• Some damaged plants can actually send out distress signals that attract pest insects. Make sure that your plants will get the right type and amount of nutrients. Healthy plants are often less susceptible to damage from insects and disease.
• Consider the amount of sunlight, water, and air circulation that your plants will get as they grow. Select plants that are known to grow well in the conditions that you have in your garden space.
• Consider planting so that weeds will be shaded out, but not so close that there is low air circulation. Low air circulation can lead to the spread of disease.
• Practice Integrated Pest Management (IPM) by identifying your pests, determining how many can be tolerated, and making changes in the garden to discourage those pests. For example, you might create a physical barrier, or set traps to reduce the population of pests.
• If you choose to use a pesticide, consider selecting one that will target your pest specifically, rather than using a broad-spectrum product. Biological pesticides, for example, are made to target a specific insect or group of insects.
• Avoid treating plants that are in bloom. Beneficial insects may be visiting the flowers.
• Get to know your beneficial insects. We can help you get started with this quick list and the picture guides linked below.

Additional Resources:

• Incorporating Beneficials into the Gardener's Toolkit - Clemson University
• Gardening and Landscaping Practices for Nesting Native Bees - Utah State University Extension
• Biological Control and Natural Enemies of Invertebrates - University of California-Davis
• Natural Enemy Releases for Biological Control of Crop Pests - University of California, Agriculture and Natural Resources
• Beneficial Insects and Spiders - University of Maine
• Gardening for Pollinators - US Forest Service

Pictures of Beneficial Insects:

• Beneficial Insects in the Yard & Garden - University of Nebraska
• Natural Enemies Gallery - University of California-Davis
• Beneficial Predators - University of California-Davis
• Beneficial Parasitoids - University of California-Davis
• Biological Control and Natural Enemies of Invertebrates - University of California-Davis
• Biological Control: A Guide to Natural Enemies in North America - Cornell University
• Beneficial Insects: Nature's Pest Control - Cornell Insect Diagnostic Laboratory
• Common Natural Enemies of Crop and Garden Pests - Purdue University

If you have questions about this, or any pesticide-related topic, please call NPIC at 800-858-7378 (8:00am - 12:00pm PST), or email at npic@ace.orst.edu.