Integrated Pest Management
This summer, we have dealt with various insect pests of all shapes and sizes. We got one issue sorted out no sooner than another one popped up, causing significant damage to the host plants. In several cases, the best treatment was using chemicals to help control the pests. However, chemicals may not always be the best first response to seeing an insect in your garden, landscape, or lawn. In many instances, unless the issue is severe, other steps should be taken first to control the problem, or in some cases, some steps could have been taken to prevent the issue in the first place. I will never say that using chemicals is bad as they are an essential tool in the toolbox, but they should never be the only tool we use. This week, we will discuss integrated pest management and its importance to home gardeners.
Integrated pest management, or IPM, is a comprehensive approach to managing pests in your home garden, landscape, and lawn. IPM is characterized by using various methods to control pests while causing the least harm to the environment, people, and property. The goal is to manage the insects at levels that will not cause damage to the desirable plants but do not focus on eliminating the pests. While your first thought might be that getting rid of the problem insects would be the best option, in many cases, those insects support a population of beneficial insects that help our plants, or the amount of chemicals needed to eliminate the issue would cause significant harm to the environment. IPM looks at managing pests through three different avenues: cultural, biological, and chemical.
Cultural Control- One of the first steps with IPM involves using cultural control methods to create a less attractive environment for insects. The goal is to reduce pest establishment, survival, reproduction, and dispersal by making small changes to how you garden. Cultural control can include changing your irrigation practices to minimize disease issues, using mulches around plants, and using traps to scout for insects before they become an issue.
Biological Control- An essential aspect of IPM is to utilize natural beneficial insects as much as possible to help reduce the number of harmful insects in your garden. Biological control can refer to using natural predators to attack aphids, or it could also include cultural methods such as using polycultures to encourage more natural predators in the garden.
Chemical Control- Last but certainly not least, chemicals help control insect or disease issues in the garden. In IPM practices, chemicals are combined with cultural and biological controls for more effective long-term control. The chemicals used should be selected for their lack of impact on the environment and their efficiency at controlling the pest. You want to use as selective a chemical as possible. With IPM, you should wait to apply chemicals until you reach the threshold for that particular plant and the insect pest. As I stated earlier, chemicals are an essential tool in the toolbox; however, the key is ensuring you use the right tool for the right issue.
The first step in IPM is to think before you plant any plant. Plants that aren’t suited for that location will
be more likely to be stressed, and those plants will have more pest issues than plants in the conditions they prefer. In a vegetable garden, it is important to rotate your plants rather than planting the same thing in the same spot every year. There has also been some research that shows planting monocultures of vegetables could increase pest issues compared to utilizing a polyculture. If possible, encourage beneficial insects such as parasitic wasps, ladybugs, and lacewings that can help to control the pest’s outbreaks before they become a problem. The second step is to work to keep your plant as healthy as possible (I know that’s always the goal) so they are less likely to have pest issues. Avoid over-watering or over-fertilizing, thinking this will help the plants; it makes them more likely to have problems with insects because of the extra growth. The third step is one that we already do routinely, and that is to scout your plants regularly. Don’t check the same plant in a row each time; try to check different plants or multiple plants in a section. If you do find a pest, identify it before beginning any treatment. One of the most important aspects of IPM is always to figure out what is causing the problem you are seeing.
When you find an issue, because, let’s be honest, at some point, you will try to remove the affected leaves or the insect itself if possible. If the plant is heavily infested, it might be best to remove the plant completely, as it will be challenging to bring those insects down to a manageable level. If you see pests show up, don’t treat them immediately; check for beneficial insects to know if they are handling the issue, and if the problem is only cosmetic damage, there isn’t a need to treat. Every plant has what we call a “threshold level” for an insect, which is the level of the pest population at which the plant is approaching yield loss. This is the level at which it is time to start treating. This threshold level could be expressed in the number of insects per leaf or the number of plants with pests in a row. If possible, find out what that level is and wait to treat it until you reach it. When treating any insect pest, use a selective chemical rather than a broad-spectrum product. Some research has shown that broad-spectrum products can worsen an issue by killing any beneficial insects that were there, helping to control the pest. If you need to tap a nail into a picture frame, a sledgehammer won’t be your best option, but a small hammer would be. Try to spray any product early in the morning or right at dusk to reduce the chances of hurting beneficial insects.
Integrated pest management involves many techniques gardeners use in their yards and gardens. For many, it takes a few adjustments to your routine to utilize IPM at home. Remember, if you are using any chemical, even organic ones, you must read and follow the label at all times for the product to be the most effective. Many times, when people tell me a product failed to work correctly, it was because they hadn’t applied it as recommended on the label.
Have questions? Contact our office where our Horticulture Extension Agent will assist you with questions.
Phone: (316) 321-9660
Email: callae@ksu.edu