To Use or Not to Use – Pesticides
Warm weather brings more folks out into the garden than just us. As tender shoots begin to stretch up and buds swell, we start to get excited about what comes next. So do the neighborhood pests and the migrating hordes of four, six and eight legged unwanted guests. Our office often gets calls that begin with “What can I spray to get rid of these ______ (fill in the blank with the pest of the day). The response to the callers’ concerns begins with a brief discussion of IPM – integrated pest management because “spraying away the problem” doesn’t really work long term. While there are a few exceptions, it is rarely necessary, or even possible, to totally eliminate a pest.
The most effective strategy for controlling pests is to combine methods in an approach known as Integrated Pest Management (IPM). In IPM, information about pests and available pest control methods is used to manage pest damage by the most economical means while minimizing risks to you, your pets, and your environment. So we need to consider some basic pieces of this strategy in order to be productive with our time, money and energy.
The first step is prevention. Cultural and physical control practices begin before pest problems even begin. What this means is to provide desired plants with a healthy growing environment that is based on appropriate site selection, soil make up, plant selection, watering, fertilization, and sanitation (clean up). Prevention through physical control means using screens, floating row covers, traps, baits, lures, and physical repellents. Barriers such as mulches help to reduce weed growth and maintain adequate soil temperatures and moisture.
Next comes accurate identification. Know your enemy. To be able to effectively control a pest, you must first know something about it to make a sound management plan. Notice the physical features of the pest (especially the mouth parts); know what healthy foliage looks like on your plants so you can spot when things are not right; learn what host plant an unwanted organism lives on or prefers to eat; find out the pest’s life cycle and what damage looks like when they’re feeding or nesting; as well as what weather conditions that favor the pest.
After you spot your enemy, determine how much of a threat they really are. Decide how much is too much – set your tolerance threshold for taking action or not. Can your plants tolerate and resist the pest? Or are conditions right for the “perfect storm” of rapid spread. Usually your goal will be to keep the population in check since total elimination isn’t likely to happen anyway. Remember that our gardens are part of the natural ecosystem – which includes organisms that we deem as pests. Trying to completely eliminate a pest can change the whole system, possibly killing beneficial insects or allowing other insects to become a pest instead. For example, heavy insecticide use can lead to an increase in mite population because the natural predator/prey checks and balances have been altered. Mites are not insects, but can still be problem pests.
Finally, take action. When you’re approaching that enough-is-enough threshold, use the best biological, chemical or combination of control agents you can. Biological control uses beneficial insects that feed on the pest insects. Remember that beneficials need appropriate shelter and food for each stage of their lifecycle if they’re going to stay around and work for you. A chemical control component may be a practical addition to your pest management plan. Be mindful to use insecticides which kill only the target pest, not the beneficial insects. Treat only the areas where the pest is present, using the right pesticide at the most susceptible lifecycle stage to be the most effective. ALWAYS read the label before purchasing any pesticide and then FOLLOW the label directions exactly. More is not always better, and sometimes results in disastrous and unintended consequences.
Minda Daughtry is Horticulture Agent for North Carolina Cooperative Extension in Lee County.