Integrated Pest Management · Agriculture and Natural Resources
University of California
Protecting natural enemies and pollinators
The natural enemies of plant pests are valuable in an integrated pest management approach, and their conservation is important for crop health. Natural enemies (predators, parasites, or pathogens) help prevent damage to crops by reducing pest populations below levels that cause crop losses. Pollinators such as wild and commercial honey bees are also essential for many California crops.
Natural enemies and pollinators can be harmed by pesticides, and they are often more susceptible than the targeted pest. For instance, many plant pests are stationary, while natural enemies and pollinators move about, and may encounter pesticide residues in more places.
To maintain healthy populations of natural enemies and pollinators, use pesticides sparingly and in accordance with the label and local regulations. Also consider these general guidelines for pesticide applications:
Choose selective pesticides
Identify the pest, and use the resources on this Web site to determine which pesticides will specifically control that pest. Avoid broad-spectrum insecticides such as organophosphates, carbamates, and pyrethroids, which indiscriminately kill everything. Also avoid broad-spectrum herbicides, which reduce floral plants that attract pollinators.
Choose nonpersistent pesticides
Some pesticides leave residues that kill natural enemies and pollinators long after the initial application (residual toxicity), in addition to immediately killing them (contact toxicity).
Choose less harmful formulations
Generally, dusts, powders, and microencapsulated pesticides are the most harmful to honey bees, and aerial spraying is the most hazardous method of application. Liquid solutions and granules are the least detrimental to pollinators.
Targeting your application to specific areas where the pest is a problem will reduce the harm to natural enemies and pollinators.
To protect pollinators, avoid spraying when flowers are in bloom. Apply pesticides during the evening or early morning when pollinators are less active. Do not apply when temperatures will be especially low or when dew is expected. Risk of pesticide toxicity is prolonged under these conditions, since residues remain on plants longer.
Communicate with beekeepers
Talk about your pesticide applications with nearby beekeepers and know where colonies are located. Healthy bee populations and abundant nectar sources create a mutually beneficial relationship between beekeepers and growers.
Use the Pest Management Guidelines to look up the impact of specific pesticides on natural enemies and pollinators. Each crop has a table of Relative Toxicities of Insecticides and Miticides to Natural Enemies and Honey Bees under the General Information section.
Homes and landscapes
For home and landscape pesticide use, assess the hazards of particular pesticides using the Home & Landscape active ingredients database.
- Natural Enemies Handbook, UC IPM Publication
- Natural Enemies Gallery, UC IPM online database
- Biological Control and Natural Enemies, UC IPM Pest Note
- Beneficial Predators, UC IPM Quick Tip
- Parasites of Insect Pests, UC IPM Quick Tip
- What is IPM?, UC IPM Quick Tip
- Pollinator Conservation Resource Center, Xerces Society for Invertebrate Conservation
- How to Reduce Bee Poisoning from Pesticides, from Pacific Northwest Extension
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