When most people think of insects, bad ones come to mind. Fortunately, the vast majority of insects in the world are not pests and because every pest has a predator, many insects are beneficial.
Beneficial insects are insects that help your grow healthy plants. The most commonly thought of beneficial are the pollinators such as honey bees. But, there is a group of insects that either eat or parasitize unwanted garden pests. Knowing how to attract those beneficial insects to the garden is important.
The first step in attracting beneficial insects to the garden is to stop using pesticides. These chemicals do not differentiate between the good and the bad bugs. Be patient. If your peppers have aphids, give the ladybugs time to find the smorgasbord, eat, mate, lay eggs, and let the ladybug larvae continue to pick the plants clean.
Planting an insectary in or near the garden will help attract the beneficial bugs to the neighborhood. An insectary is a garden plot or section of the plot dedicated just for the insects. The garden can be a landscape bed right near the garden, or several small plantings interspersed among your current flowers or veggies.
Flowers such as fennel, yarrow, and dill, and composite flowers, such as daisies, cosmos, and zinnias, are two important flower shapes that attract insects who, in the adult phase, feed on nectar and pollen but whose larvae are voracious predators and parasites. Some of these insects include hoover flies, lacewings, and parasitic wasps.
Low cover is important for ground beetles that feed at night on slugs, cutworms, and root maggots. This cover can be low-growing herbs, mulch, flat stones, or boards. Taller plants are important for predators such as stink bugs and praying mantids. Many times these large, predatory insects hide so well in the tall plants, that we don't even notice they are there!
Like all living things, beneficial insects need water. This need can be met by simply placing a water-filled saucer with some rocks in and around it in the garden. Most of these insects have wings and will move out of the garden if water is not available.
With some time and an understanding, even the most bug-squeamish gardeners can come to appreciate the importance of beneficial insects and biodiversity within the garden!
Anne Lenox Barlow has had experience in the agricultural field as a horticulture educator with Cornell Cooperative Extension in Clinton County. She can be reached by e-mail at firstname.lastname@example.org.