Michael R. Bush and Sharon J. Collman
Latest revision: 
March 2023

Includes management options for commercial and home use.

In all cases, follow the instructions on the pesticide label. The PNW Insect Management Handbook has no legal status, whereas the pesticide label is a legal document. Read the product label before making any pesticide applications.

In this section

Not all users of the PNW Insect Management Handbook are from the states of Washington, Oregon or Idaho. Every effort is made to ensure that the active ingredients listed here are currently registered for the host/pest use in these three states. While many of these pesticides are registered in all states, check to ensure the listed product is registered and legal for the same uses in the state where the application is planned.

Pesticide products are arranged alphabetically by common name of the active ingredient and are not listed in order of preference or superiority of pest control. These products are registered to control pests found in ornamentals and home landscape plants only. These products may not be registered (thus legal) for all host plants that a pest can attack and some products may be phytotoxic to certain host species. Check the label to be certain the product you select is registered for both the host plant and the pest you plan to treat.

Protect Pollinators:

See: How to Reduce Bee Poisoning from Pesticides in this handbook or at

See: Neonicotinoid Pesticides and Honey Bees

Many insecticides are highly toxic to honey bees, bumble bees and other insect pollinators. Some insecticides should not be applied at any time during plant bloom, while others should be applied only in the early morning hours and/or late evening when pollinators are not active. Refer to the product label for bee toxicity and proper application timing. Avoid spraying insecticides on blooming flowers or weeds surrounding targeted host plants. Always take simple steps, like removing (mowing) blooming clover from lawns adjacent to garden areas, before applying materials that are hazardous to bees. In all cases, when given the choice, select the least hazardous product to bees when any plant around the targeted host plant is in bloom. Avoid using dusts, whenever possible, as dusts will inevitably adhere to the bee hairs (like pollen). Liquid spray formulations are preferred for bee safety. In Washington, it is illegal for homeowners to spray host plants at heights greater than ten feet. Applications at these heights greatly increase the risk of pesticides drifting into non-target areas such as streams, neighboring yards, blooming plants, or onto the applicator themselves. Whenever the host plant is higher than ten feet, a professional pesticide applicator should be called, or a non-pesticide option chosen. Check local regulations in your state.



Chastagner, G.A., Byther, R., Antonelli, A.L., DeAngelis, J. and Landgren. 1997. Christmas Tree Diseases, Insects and Disorders in the Pacific Northwest: Identification and Management. Washington State University Cooperative Extension. 154 pp.

Cranshaw, W. 2004. Garden Insects of North America. Princeton Field Guides.

Furniss, R.L. and V.M. Carolin. 1980. Western Forest Insects. USDA Forest Service, Misc Pub 1339. Goheen, E.M. and E.A. Willhite. 2006. Field Guide to the Common Diseases and Insect Pests of Oregon and Washington Conifers. R6-NR-FID-PR-01-06. ISBN 0-16-076244-8. 325 pp. Johnson, W.T. and H.H Lyon. (1991). Insects That Feed on Trees and Shrubs. 2nd ed., Cornell University Press.


Hortsense for homeowners in Washington. Includes diagnostic tools and management recommendations for insects, weeds and diseases—

Lepidoptera of the Pacific Northwest: Caterpillars and Adults. 2003. Jeffrey C. Miller and Paul Hammond. Forest Health Technology Enterprise Team, U.S. Forest Service, USDA. FHTET-03-11. See National Pesticide Information Center (NPIC) has both a website and people trained to answer specific questions about pesticides. Information is available in several languages. See or call 1-800-858-7378.

Pesticide Information Center Online (PICOL) is a database for searching currently registered products in Washington and Oregon.

PNW Insect Management Handbookis available on line at The website includes pictures of most pests. (See also: PNW Disease Management Handbook online.