Attracting beneficial insects to the home garden
Insect pests catch a great deal of attention in the plant world. But more important and certainly more numerous are the beneficial insects that quietly go about their business pollinating our crops, decomposing waste, and preying upon those very pests that occupy our gardens. This last group, the predators, contains our friends in the insect world. In the scientific world we call our garden allies "natural enemies", because they are the natural enemies of our garden pests.
Many of our garden friends go unnoticed by even the most dedicated gardener. Some are simply too tiny to see, like many of the specialized predatory wasps we call parasitoids. Others come out to feed at night, when we are asleep. Many beetles fall into this category. It is important that we get to know natural enemies a little better and do what we can to encourage them to thrive in the garden.
Beneficial insects come in many shapes and sizes, from the minute pirate bug to the giant praying mantis. The following is just a short list of the most common natural enemies present in the home landscape. Of course, there are many others.
Beetles: ground beetle, lady beetle, rove beetle, tiger beetle, lightning bugs, etc.
Flies: hover or flower fly, robber fly, parasitic flies
True Bugs: pirate bug, assassin bug, ambush bug, damsel bug, big-eyed bug, stink bug
Lacewings: brown and green lacewings
Wasps: predatory and parasitoid wasps
Others: mantis, spiders, dragonflies, damselflies, centipedes
Even if you do not recognize all of the many natural enemies at work in the garden, there is much you can do to attract them to the garden. Like any organism, natural enemies need food, shelter, and water. Water features attract a great many beneficial animals, including frogs, toads, lizards, and birds. Water also attracts insects like the dragonfly – a voracious insect feeder.
Natural enemies need shelter from the sun and wind, and from other predators. Nocturnal insects need a place to hide during the day. Many materials we already commonly use in the landscape provide excellent shelter for natural enemies. Rocks, logs, and pieces of bark provide a great place to hide. Organic mulches such as wood chips and straw likewise shelter natural enemies. Natural enemies also need a place to spend the winter. Perennials and ornamental grasses are ideal over-wintering sites. Wait to cut these plants back until spring. In a vegetable garden, cover crops can provide winter shelter for natural enemies.
Predators of course feed on insects and other invertebrates, but they also utilize supplemental food sources, mainly pollen and nectar from flowers. Planting an abundance of flowers throughout the landscape is the best way to attract beneficial insects to the garden. Plants used to attract beneficial insects include a number of garden favorites. And many of the plants used to attract natural enemies are also attractive to butterflies. Several common herbs, when allowed to flower, are also highly attractive to natural enemies. Some of these herbs spread quickly if allowed to seed; remove flower heads when blooms fade to avoid seeding.