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While inspecting your plant material, you find an insect. Often the next step is a stop at the chemical storage shed to find an appropriate spray product. But with a new year should come a new way of approaching your pest management program. Why? For a variety of reasons — from environmental to economical.
A few good reasons
On the environmental front, the fewer pesticides used, the better off the environment will be. David Pimentel of Cornell University conducted research and found that only 0.1 percent of pesticides reach their target host. This means the rest runs off or drifts away into the environment. Before you treat with a pesticide, make sure you have looked at all other options, and use pesticides only as a last resort.
Thinking about sustainability, we need to conserve efficacy of existing pesticides for when we really need them. Over-using them can lead to pesticide resistance issues (which we are already seeing in products containing imidacloprid, abamectin and glyphosate).
From an economic standpoint, you are wasting money when spraying a pesticide that will not kill your target pest, or even worse, your pest is already dead. Robotic treating on a simple predetermined calendar schedule is inefficient and can be a waste of money and labor.
Before you spray
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 Positive identification is key to good pest management. Indian wax xcale can only be removed mechanically.
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It’s tempting to see an insect or mite on a plant and immediately assume you need to kill it. But next time you find a little multilegged critter, make sure you evaluate the situation first.
Is it really a pest? Very few insects are actually pests. Take the time to identify insects accurately, and if you cannot make a positive ID, get help. There are many excellent books and websites that can help if you’re not sure. Once you have the insect identified, ask yourself if it could be a beneficial. Many beneficials mimic themselves as pest insects. Also, beneficials are often found near pest insects, because the pests are their food source. If you come in with a spray that will kill the beneficials, your actions may just allow the pests to get ahead.
If the insect has been identified as a pest, make sure it is not already dead. This is a common mistake often made with the scale insects. Scales are often controlled naturally in the landscape and nursery setting by parasitic wasps and/or ladybird beetles. Scale insects excrete a waxy substance that is not palatable to predators and parasites. Since their predators are more interested in the insect’s body under the wax, this excretion is mostly left behind. At quick glance this excretion may look like a live insect, but with closer examination using a 10X hand lens, you can see that the “meat” of the insect is gone. Also look for circular holes where parasites may have hatched out of the host.
A pest may already be dead is if a slower-acting pesticide has previously been applied, like some of the neonicotinoids. Imidacloprid is a good example of a slow actor. Sometimes it can take a while to begin working in woody plant tissue, but it will persist for a fair amount of time. It still may be providing crop protection when a new pest strikes, therefore killing it. The dead body of the pest could be stuck to the plant. Double check to save time and money.
It’s alive
If you find your bona fide pest is alive and well, feasting away on your plants, a plan of attack must be decided. Instead of going for the “big guns,” see if some softer methods might work first.
Start with seeing if the problem can be mechanically removed. Sometimes this is your only choice, such as in the case of Indian wax scale in the fall. Unfortunately, for most pests, this method is not going to work. Determine if it’s something you can control using biological control. The biological control of today is not the biocontrol of even five years ago. Many advancements have been made in application, what can be controlled, and how biocontrols can be integrated into traditional spray programs. Pests that are successfully being controlled by commercial growers with biological control include fungus gnats, spider mites, thrips, aphids, whitefly, black vine weevil and some caterpillar species.
If there is not a bug to eat your bug, then maybe a softer spray can do the trick. Products like BotaniGard and Met 52 each contain a beneficial fungus that targets insects. Another softer targeted product is Bacillus thuringiensis (Bt), the active ingredient in Dipel. Bt only kills caterpillars once they ingest it, not harming your beneficials.
If none of the above options are going to work, try horticultural oils and insecticidal soaps, which have a great track record for killing many pest insects and mites. However you must get 100 percent coverage of the pest for these products to work. You also have to be careful of things like open flowers, and sometimes oils and soaps can discolor blue plants. Follow the label to avoid any phytotoxicity problems.
Using pesticides
If traditional pesticides must be used, start with your more targeted products. Insect growth regulators (IGRs) are proving to be a valuable tool in the chemical shed. To use IGRs, you will need to understand the pests’ life cycle. This is important because IGRs do not normally control the adult life stage -- they target immatures. IGRs help break the life cycle and are often softer on biological control agents.
If you are still unable to gain the upper hand, move onto more traditional chemistries. When using these products, always read the label and make sure your pest is listed. This is true of any spray pesticide product. Make sure you apply the product to where the pest specifically is to prevent excess spraying (and profit loss). Check your spray water pH because some pesticides are pH sensitive and may not perform up to their optimum potential.
With the new year, try to rethink the traditional approach to pest management. Sometimes pesticides are needed to control hard-to-kill pests, but many can be controlled by alternate or softer methods. Identification is essential to prevent needless pesticide applications that can be quite expensive, as well as harmful to the environment.
Before mixing up that next spray tank, check to see if it is really necessary.
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