Beneficial Insects 101
A garden is a buggy place. Garden plants attract insect pests by the dozens, from aphids to slugs. But before you reach for an insecticide, take another look at the insects in your planting beds. While the pests are devouring your squash and tomatoes, another wave of insects is coming to the rescue. Beneficial insects prey on the pests gardeners detest, keeping insect populations in check. Learn and recognize if you have the following insects in your farm:
Most of the beautiful adult lacewings feed on pollen, nectar, and honeydew. Green lacewing larvae, however, are voracious predators. Nicknamed “aphid lions,” the larvae do an impressive job of devouring aphids by the dozens. Larvae hunt for soft-bodied prey, using their curved, pointed mandibles to stab their victims.
Lady beetles eat aphids, scale insects, thrips, mealybugs, and mites—all the pests’ gardeners despise. With lady beetles, you get more bang for your buck, because both the adults and the larvae feed on pests. Lady beetle larvae look like tiny, colorful alligators.
Assassin bugs know how to take care of business. These true bugs use trickery, disguises, or just plain brute force to capture a meal. Many assassin bugs specialize in certain kinds of prey, but as a group, assassins feed on everything from beetles to caterpillars. They’re fun to watch, but be careful handling them because they bite—hard.
Praying mantis can handle even the largest pests in the garden. You need a good eye to spot
Minute pirate bugs usually measure a mere 1/16th inch long, but even at that size, they can put away a good number of aphids, mites, and thrips. Next time you’re
Ground beetle larvae feed on pests that live in soil, including cutworms and slugs. The dark-colored adults often have a metallic sheen, but it’s really the larvae that do the dirty work of pest control. Ground beetle larvae develop in the soil, and prey on slugs, root maggots, cutworms, and other pests on the ground. A few species will venture up a plant stem and hunt for caterpillars or insect eggs.
Syrphid flies often wear bright markings of yellow-orange and
Though many stink bugs are plant pests themselves, some predatory stink bugs keep pests in check. The spined soldier bug, for example, feeds on caterpillars, sawfly larvae, and grubs. Most predatory stink bugs are generalist feeders, so they might also devour your lady beetles or even their own kin. You can recognize stink bugs by their shield-shaped bodies, and the pungent odor they produce when disturbed.
Here are some steps that you might consider taking to help them help you.
(1)Include a variety of native plants (including flowering varieties) in and around crops to attract different types of natural enemies. This will help provide food and shelter for a variety of beneficial insects.
(2) In small-scale agricultural settings, it may be possible to break up your plantings. Consider intercropping a variety of crops to attract and shelter a variety of natural enemies.
(3) After harvesting field crops, consider planting the area(s) with a variety of cover crops to provide habitat for some types of beneficial insects.
(4) Practice Integrated Pest Management (IPM): identify the pest, decide how much damage can be tolerated, and select control methods that will be most effective while minimizing risks.
(5) Avoid treating plants that are in bloom. Pollinators and other beneficial insects may be visiting flowers. Don’t forget, this includes flowering “weeds.”
(6) Avoid applying pesticides to plants when natural enemies are present and active in the area.
(7) Make sure that your plants will get the right amount of nutrients, water, air circulation, and sunlight. Healthy plants are often less susceptible to damage from insects and disease.