While a lot of people do not like seeing insects on their garden plants, several insect visitors are beneficial to your plants. Most often insects are considered beneficial when they kill or eat other insects that are known for harming garden plants. Pollinators are also beneficial in the garden. Many insects have natural enemies. Spiders are very beneficial in the garden. Beneficial spiders include the harvestman (daddy longlegs), ground or wolf spiders, crab spiders, and orb weaver spiders. Spiders in general are often natural enemies of most other insects, making them a great insect to find near your garden plants. Some spiders will create webs in which pests get caught in while other spiders prefer to hunt prey on the ground or the plant foliage.
Damsel bugs AKA Nabids are another common garden insect found in Alaska. They eat pests such as aphids, moth eggs, and caterpillars. They are enticed by natural grass areas. Green and Brown Lacewings are another insect that feed on aphids, mites, whiteflies, and eggs of destructive caterpillars. Ground Beetles are a large group of insects that hunt on many types of insects. Permanent plantings, walkways, mulch, and structures increase beetle populations. Lady Beetles are one of the well known types of beneficial insects. Lady Beetles are often sold at farm supply and garden centers due to their predatory behavior towards aphids.
Flower Flies resemble bees, however they are completely harmless and do not sting. These flies have been known to feed on aphids and other soft-bodied insects. As they reach adulthood, they do not feed on insects, but they are a great pollinator. Adults are attracted to flowering plants. Robber flies feed on a variety of insects including bees, wasps, and grasshoppers. Yellowjackets are often viewed as an enemy to humans, but they are considered beneficial in the aspect that they do eat flies, aphids, caterpillars, and other pests. Just be cautious of yellowjackets as they have a powerful stinger. Parasitoid wasps do not sting people, although they look similar to other stinging insects. They are useful in greenhouse control as well as outdoor garden control. Parasitoid wasps lay their eggs in, on, or near host insects. Parasitoid flies are similar in the aspect that they lay their eggs directly on the host insect or on something the host would eat. The larvae then eat and kill the host insect.
Pest management requires multiple layers for success. Increasing the number of beneficial insects to your garden is one way to help reduce the harmful insect population near your plants. Be sure to know what beneficial insects look like so that you are familiar with them. Seeing a bunch of predatory insects could indicate that you have a pest problem and aren’t aware of it.