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Yard Wars

Have you ever sat in your yard for a couple of hours, next to the perennial border or the vegetable garden, and just watched, very closely, what the insects were doing? Maybe this pastime is just a crazy-field-biologist thing -- but, then again, you might be surprised at how fascinating it can really be.

Your garden, especially when it contains a lot of native species, is home to a whole insect ecosystem. There are producers (your plants), primary consumers (the plant eaters), secondary consumers (the predators), and decomposers (that process decaying organic matter until it is once again usable by the producers). If you are an avid gardener rather than a weed-grower, you are probably not thrilled with the primary consumers that are snacking on your plants. Some primary consumers, such as butterfly larvae (caterpillars), are worth sharing with, though. The adult butterflies, besides being beautiful, are important pollinators.

Many of the plant eaters are just considered pests. This is where the predators come in. If you have a healthy ecosystem there will be enough of these beneficial insects to keep the pests well under control and win the war. Learn to identify the insects in your yard, and you will keep this balance without using pesticides. This is great news for people with vegetable gardens who want to keep butterflies and other useful pollinators around. It also makes for healthier vegetables and a safer place for the kids and the pets to play, to say nothing of the benefits to the environment as a whole. If you get to know your common garden insects, you will know which ones to pick off of your plants and which ones to encourage. A wealth of information can be found on the Internet, through garden suppliers, or at your local extension office. The list of beneficial insects includes parasitoids and predators of pests as well as pollinators of vegetables, fruits, and ornamental flowers.

The parasitoids, mainly wasps and flies, are an important and often overlooked group of beneficial insects. Parasitoids lay their eggs on or in other insects. When the eggs hatch, the larvae kill their host by eating it alive. Of the predators, the bright red lady bug (actually a beetle) and the praying mantis are the most well known. They can even be purchased from garden supply companies to supplement your army. If you have ever found a small, papery mass on the stem of a plant that looks kind of like a miniature bee hive, you can be sure that you have praying mantids in your garden. In the springtime scores of immature mantids, which look like tiny replicas of the adults, will hatch from the eggs inside the egg mass. Watch your garden closely and you can watch their progress as they increase in size over the summer.

There are several species of true bugs that are common garden-dwelling predators. A true bug is actually a particular type of insect: all bugs are insects, but not all insects are bugs. Bugs are superficially similar to beetles, but do not have the completely encased wings of the beetles. Bugs have only half-covered wings, hence the scientific name of the order: Hemiptera (meaning "half wing"). They also have piercing-sucking mouthparts, which make some of them plant pests and others great predators. One of the easiest to recognize is the assassin bug. It is usually brown, has a hump on its back that looks like a gear standing on end, and has a narrow head with a long, impressive "beak" that curves down under the head. This "beak" is used to attack its prey and can also give a human a rather painful stick, so picking one up is ill advised. Even the tiny immature assassins can get you, which I have personally tested out. Other helpful bugs include the bigeyed bug, minute pirate bug, ambush bug, and the spined soldier bug (which looks very similar to a stink bug).

Ground beetles are quite common and will eat slugs, snails, and many other garden pests. The soldier beetle will get those pesky cucumber beetles, among others. Rove beetles will eat aphids, and some species are useful as decomposers. Immature lacewings, also called ant lions or aphid lions, are voracious predators. Some of the adults are also predators while others feed on pollen and nectar, thus helping with pollination. Robber flies eat grasshoppers and other pests, and can catch their prey in the air. Hover flies or flower flies look like little bees because of their striped bodies, but are harmless to humans. The larvae feed on aphids and the adults are pollinators, feeding on pollen and nectar.

Pollinators are especially important for those with vegetable gardens, berry bushes, or fruit trees. Without pollination of their flowers, fruits and vegetables like apples, strawberries, cucumbers, squash, or melons will not grow. The benefit of these insects to American consumers can be measured in the billions of dollars. Bees and butterflies are usually the first insects that come to mind when one thinks of pollinators. However, flies, beetles, lacewings, bugs, and moths also play an important role in this capacity. You can thank them all for your luscious tomatoes, cool cucumbers, and sweet apples.

Areas of cover, like perennial beds, mulch, and stepping stones, will attract beneficial predatory insects. Many are also drawn to goldenrod, yarrow, daisies, or alfalfa. Pollinators will come if you have an abundance of blooms of many types. Limiting or eliminating your use of pesticides is the most important step in attracting and keeping the insects that make up your yard's insect ecosystem. Now find a comfortable spot and sit very still....