Pesticides as Insect Control in the Home Garden

August 16, 2003

By Lee Oliphant, Ed.D., Master Gardener

PART 1 of 3


No Master Gardeners worth their salt are going to recommend that you indiscriminately spray insecticides as a means of pest control.  There are numerous proven strategies available for the home gardener that will create a natural balance in the environment and manage pests, while minimizing damage to plants and wildlife - all without the use of chemical substances.

But let's face it, there are times when the home gardener feels the need to rely on technical support through the use of biochemical warfare. Before doing so, thoughtfully evaluate your reasons for this action. Are pests causing unacceptable losses in your garden beyond your tolerance? Do you completely understand what is causing the damage? Are you treating the offender(s) at the proper time in their life cycles? Do you know how to read the pesticide label and use the appropriate dilution formula?

Know Your Enemy


The
University of California has developed strategies known as integrated pest management (IPM) encouraging gardeners to take a holistic approach to managing pests. Important components of the IPM program are pest identification; monitoring and predicting pest outbreaks; knowledge of the biology of the pest including how and when it feeds; and knowledge of the pest's natural enemies.

By identifying the culprit that is causing the damage in your garden, you will have completed the first step in selecting the appropriate pesticide and applying it effectively. There are some excellent resources available that will help you identify the insect or mite, for example, which may be causing damage in your garden. Pests of Landscape trees and Shrubs, and Pests of the Garden and Small Farm are published and available from the
University of California. Pest notes on individual insects, and appropriate control measures are available at no cost online at www.ipm.ucdavis.edu or may be requested by mail by calling the Master Gardeners desk noted below.

While the mere presence of an insect on a plant does not necessarily mean that it is the offending critter, finding and capturing the insect is the best way to get help with its identification. Some pests are elusive and this may not always be possible. To help you identify the damaging insect, note whether or not the leaf has been chewed, or is discolored or withered from the sucking mouthparts of insects such as mites, scales or aphids. Identify the kind of plant that is affected. Some plants are prone to particular insect infestations. Know the lifecycle of local insects. Some go through complete metamorphosis (beetles and butterflies) while others, like aphids, change little as they mature.

Identifying and understanding the offending insect, its growth and its habits, will help you select the appropriate control measure and apply it at the proper time in the life cycle of the insect. Subsequent articles on types of pesticide and formulations, and reading pesticide labels will follow, as well as information on the use of pesticides for maximum results.

University of California Cooperative Extension Master Gardener Volunteers can provide additional gardening information upon request .Call the San Luis Obispo office at 781-5939 on Mondays and Thursdays from 1 to 5 PM.  You may also call the Paso Robles office at 237-3100 on Wednesdays from 9 AM to 12 PM.  The San Luis Obispo Master Gardeners website is at http://groups.ucanr.org/slomg/. Questions can be e-mailed to: mgsanluisobispo@ucdavis.edu.