IPM vs. A “PROGRAM”
IPM is Integrated Pest Management. The basic service includes inspections and monitoring for harmful levels of pests or harmful diseases in landscape trees and evergreens. Targeted and specific treatments can then be used to control a problem if it is amenable to control. Treatments have the goal of preventing damage to the trees and evergreens. Not all insects or diseases need to be treated. And when treatment is needed, there are many alternatives to sprays that are much less invasive to the environment and that help preserve or enhance natural controls. Good examples of insects which do not need control are aphids and many types of mites. An example of a disease which does not need control is ash anthracnose. Unnecessary sprays often kill the predator insects- the good bugs – which help to keep pest insects under control.
The “program” offered by many landscape companies, garden centers, and lawn care companies is a multiple cover spray regimen. Several sprays and treatments are applied during the warm months, using combinations of pesticides, in hopes of preventing pests and diseases, but often not doing either. The treatments do not have specific targets or timing and the pesticide mix is often illogical and may actually exacerbate the very pests they are applied to “control.” Most serious infestations of scale insects or mites are a result of indiscriminate spraying practices.
Cover sprays (that is, spraying all the trees and shrubs at the same time with the same chemicals) are never appropriate. They result in excessive pesticide use and its attendant environmental toxicity. They upset the ecology and natural controls by killing beneficial insects. Many trees and evergreens are sprayed unnecessarily and may be physically damaged by the spray itself. Often the reason for spraying is said to be to control “aphids and mites.” In fact, aphids rarely need to be controlled, even if present in large numbers. Mites need to be controlled only on certain plants at certain times. Mites are usually kept in check by beneficial predator insects and predatory mites if those beneficials are not killed by inappropriate sprays.
Sometimes sprays are the best treatment, but with the following cautions:
- Targeted sprays for specific problems should be applied with proper technique and with the specific pesticide for the pest or problem at hand.
- Whenever possible, the pesticide should not be mixed with others unless the plant to be sprayed has pests and diseases which need each component in the mix.
- Timing must be right. Applying insecticides at the wrong time in the life-cycle of a pest can actually make the problem worse. A good example is spraying for cottony maple scale or lecanium scale in May or June when the sprays cannot kill the scale insects, but do kill the predator insects like ladybugs and parasitic wasps (see scale treatment page).
- Applying fungicides at the wrong time usually causes no harm but is a waste of chemical and applies pesticides to the environment unnecessarily.
- Miticides should be applied alone and should be selective miticides for best effect. We often see the spray sellers apply illogical mixtures of miticide with insecticide, which kills the mites but also kills the beneficial insects that help to keep mites controlled naturally. The mite population recovers faster than the predators and can actually cause a worse mite problem.
- Identification of problems that need specific sprays is best done by a certified arborist with specific training and interest in IPM.
The spray program of many lawn care companies has no scientific basis and is usually not based on a certified arborist evaluation or knowledge base. Some of them even offer trunk injected nutrients or insecticides, a practice which should really only be done by a certified arborist.
In other words, please beware. There is a difference! The “program” offered by a lawn care company may be cheaper in the short run, but may not be in your trees’ best interests.