 | Gardeners know that insects in the garden are a fact of life. Controlling pests is a big part of the gardener’s job. But, there is help to be found from an unlikely source, other insects. Gardeners have used beneficial insects for pest fighting for many years. Bringing certain predator and parasitic insects into the garden is a smart and efficient way to control some pests, reducing the need for pesticides.
Ladybugs, sometimes referred to as ladybird beetles, can consume large amounts of aphids. The adult insect as well as its larvae are known to eat whiteflies, scales and the eggs of Colorado potato beetles.
Lacewings are another good choice for pest control. While the adults only feed on nectar and pollen, their larvae have pincer-like mouths that suck juice from other insects bodies and also from their eggs, eventually causing death. Some of the insects they kill are mealybugs, aphids, whiteflies and spider mites. Lacewings can be purchased by mail order and are often shipped as eggs in rice hulls that can then be spread about in the garden. The larvae begin eating as soon as the eggs hatch. In approximately two to three weeks, they develop into adults and, in turn, lay more eggs. Thus, the cycle continues to supply the garden with these beneficial insects.
Parasitoid wasps, unlike the more familiar paper wasps and yellow jackets, do not sting. These are tiny wasps that lay eggs on the larvae and eggs of some common garden pests. When the wasp eggs hatch, their larvae consume the hosts. One type of these wasps destroy the eggs of moths and butterflies, which helps to control cabbageworms, tomato hornworms, corn earworms as well as other pests.
Beneficial nematodes look exactly like the destructive form of the same insect. The only difference between the two types is that the destructive nematode eats plant roots and the beneficial one eats cutworms, flea beetle larvae, iris borers and other pests. The beneficial nematodes can be purchased in a dormant state and mixed with soil amendment such as vermiculite. This is then worked into the garden, keeping the mixture in the top few inches of soil.
Many of the adults of these insects feed on nectar and pollen, so maintaining the populations of the beneficials is best achieved by growing the right types of flowering plants nearby. The flowers of plants such as aster, sweet alyssum, nasturtium, daisy and yarrow all provide nectar that will nourish the adult insects and encourage them to remain in the garden. Including a variety of plants in the garden that bloom at different times throughout the growing season will assure a steady supply of food. Planting herbs is a good idea. Beneficials are attracted to the blooms of many herbs.
Learning to use beneficial insects in the garden is well worth the effort. There are numerous sources for ordering the insects and they can be shipped right to your door. A diversity in the types of plants in the garden will help the newcomers to establish themselves and you will soon have a balanced ecosystem requiring a minimum of chemical intervention.
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