Good Bugs, Bad Bugs
Your Lawn Plays Host to Both
My entomologist friends (yes, the people who actually study bugs for a living) are always quick to point out that there are over 800,000 species of insects in the world, and well under 1 percent of them (less than 8,000) are pests to mankind. Of those 8,000 potentially pesky insects, only about 100 are considered turf pests. That's not very many when you consider it.
When it comes to turf insects, it's important to understand that eradicating them all is impossible. The best bet is to live symbiotically with all insects, good and bad, managing situations if and when they arise. To manage damaging insects correctly, you have to be able to identify the culprit and know at what stage in its lifecycle is the best time to go after it.
There are two main insect life cycles: simple and complex. Insects that undergo a simple life cycle hatch from an egg, proceed to a wingless form (nymph) and then to adulthood. These insects from early on resemble the adult they are going to become. Some of these types of insects can live and feed in your lawn (mostly unnoticed) during their entire life cycle.
Insects with a complex life cycle undergo a transformation from the egg to larva to pupa and then become adults. Each early stage bears little resemblance to the final adult insect. Insects we consider to be wonderful additions to our yards — think butterflies — and those we don't like — grubs — fall into this category. The good news is that even grubs will feed only during a brief part of their lifecycle. Provided you don't have an overwhelming number of them feeding on your lawn's root system, they can live there unnoticed until they mature into adulthood.
Now the $64 question: What causes an outbreak of insects in your lawn and how can you prevent it? There are no simple answers. My first response is to remember that you always will have insects feeding on some part of your turf. A healthy turf generally can stand up to this. A good example is grubs chewing on grass roots. If the turf is actively growing, the chances are very good that the grubs can feed and not cause problems. There also is the likelihood that the grub will become some other animal's dinner, keeping the insect balance in check.
I cannot emphasize enough the need for good lawn care practices so that your lawn can defend itself. Proper cutting (follow the one-third rule), fertilizing at the correct times in the correct amounts and watering correctly create a strong, healthy turf that can withstand the normal onslaughts of nature.
Watering, for example, is an extremely important part of cultivating a healthy lawn if chinch bugs and certain other beetle species are a problem in your area. A lack of water will enhance an outbreak of these insects, while a properly watered lawn would allow it to withstand the attack largely unnoticed.
Definitely the worst scenario for insect management comes when an insect has no enemies and can be left to forage unchecked. This is truly a case of running amok. This happens primarily when an insect is inadvertently introduced into a landscape, which has happened numerous times in the U.S. throughout agriculture history. Beetles introduced to our soil include Japanese, European chafer, and Oriental. Their larva have ravaged lawns with no known predator in the landscape. For years, the only cure was primarily broad spectrum insecticides that wiped out all insects, good and bad. This has changed in the last decade, as new insecticides like imidacloprid (Merit or Grub-EX) have been introduced that will selectively target only the grubs of these beetles. The down side? These insecticides have very specific windows in which they must be applied to kill the grubs at the right point in their life cycle. Without the right timing, the products are virtually worthless.
So the next time you shudder when thinking about insect management, remember that there are many more good guys than bad (and many of the bad were brought in by accident) and that good lawn care practices are still your best defense.
