Beneficial Insects

The Good Guys

Predatory insects are one of the groups of beneficial insects and a common predator most people are familiar with is the lady beetle. This particular group of insects feeds on a variety of insect pests such as aphids, scale insects and other soft-bodied insects. Green lacewings are predators also feeding on aphids, scales, insect eggs (e.g., stink bug eggs), and other soft bodied insects. Wheel bugs are assassin bugs and attack a variety of insects including, caterpillars, wasps, bees, Japanese beetles and others.

This insect is fairly large and will deliver a painful bite if handled. Ground beetles, tiger beetles, rove beetles, damsel bugs, robber flies, hover flies and cicada killers are just a few of the many predatory insects.

Spiders are not insects, but are also predators of many different insects.Parasitoids are beneficial insects with an immature life stage within a single host and eventually kill the host. Each parasitoid species attacks a particular life stage of their host and this does not change. For example, there are egg parasitoids, pupal parasitoids and so forth. Eggs are laid on or in their particular host species. Parasitoids attack a specific species or closely related species.

This group of beneficial insects is typically either wasps or flies. Greenhouse pests such as aphids and whiteflies are frequently managed with parasitoids; thus reducing pesticide applications. They also occur naturally in lawns, landscapes and vegetable gardens. Areas planted with a variety of flowering plants provide resources for adult parasitoids, frequently resulting in fewer pests in these locations. Samples are sometimes brought into the cooperative extension office of tomato hornworms with white cottony ‘swabs’ sticking off of it. The homeowner wants to know what has happened to the caterpillar that had been eating their tomato plants. Each of the cottony ‘swabs’ is a pupa with a tiny wasp. They chew their way out when finished pupating and search nearby tomato plants for more hornworms.