A common reaction to seeing a bug in the garden is to either squish it or grab the insecticide and start spraying. However, many insects are beneficial rather than detrimental, so make sure to identify who dwells in your garden before you squish and spray.
Most gardeners have seen the effects of aphids. We often times cringe when we discover a plant with slightly stunted growth and turn over a leaf only to find an army of green or white teardrop shaped little bugs feasting away. Aphids love to eat our plants and there are several bugs out there that in turn, love to eat aphids.
The well-known and very common ladybug is a blessing to have around your garden and can help control aphids, their preferred food. Ladybugs also have a taste for thrips, mealy bugs and mites. The most well-known type of ladybug is red with black spots, but there are also yellow, orange, gray, and black types (with or without spots.) There are various plants that attract ladybugs to your garden. These include angelica, tansy, and scented geraniums.
When releasing captive ladybugs, first make sure you water your growing area (the ladybugs will appreciate the moisture). Then gently lay handfuls of ladybugs around the area where you want them to feast. Release them only before the sun comes up or just after the sun goes down. Ladybugs tend to be very active in the middle of the day, so if released at this time, they tend to fly off rather than settle in where you want them to dwell.
Once the population establishes itself, the females will lay small orange-colored eggs on the underside of leaves. Over time, the eggs transform into larvae that look something like an alligator with a bug head. While these larvae are not as attractive as the adults, they still can consume 30 to 40 aphids a day.
Another aphid eater (and eater of many other small, soft-bodied pests) is the green lacewing. These bright green, delicate bugs are voracious eaters and can eat up to 30 to 40 aphids a day. Named for their large, transparent green wings, they are only 1/2 to 3/4 of an inch in length. They typically live among weeds or leaves of trees and shrubs, and they have a very good reputation for staying in the area where they are released. Plants that produce high amounts of pollen and nectar, which the adults eat, attract lacewings.
The primary beneficial stage of the green lacewing is the larval stage. The larvae are flat and cone-shaped with sickle-shaped jaws, used to grasp their prey as they consume them. They are typically brown or yellow mottled with red or orange, and have short hairs or bristles projecting from their body. They remain in the larval stage before cocooning themselves in a globular white mass to pupate into adults. Green lacewing eggs are easy to recognize because they are not attached directly to the leaves, but look as though they are attached to the end of a tiny hair growing out of a leaf. This is to help keep the cannibalistic larva from eating each other as they hatch.
The true Godzilla of the garden is the Praying Mantis. This large (2-5 inch) predator camouflages itself by resembling a portion of leaf or stick. It moves remarkably fast, especially when it is striking at its prey with its powerful front legs. At rest, the mantis holds its front legs in front of it in something of a ”praying” position, the source of its name. While the mantis can fly, it usually remains in the area where it hatched.
Praying mantis will eat just about anything they come in contact with (including each other) usually depending on size. Juvenile mantis will eat aphids and thrips, and then move on to bigger things as they grow. It is not uncommon for a large mantis to attack a frog or lizard. Mantises are indiscriminate carnivores, so they will eat both good and bad bugs in the garden.
Beneficial insects do more than act as living insecticides. Some act as pollinators. Due to a recent shortage of honeybees caused by an infestation of parasitic mites, suitable substitutes are taking their place. Some of the best substitutes are the Orchard Mason bee and the Common Bumblebee.
Orchard Mason Bees are a small, black-blue type of fruit-pollinating bee. They build nests inside holes in trees, fences, and human-made ”bee blocks”. They lay 5 to 6 eggs inside their nests and then plug up the entrance holes with mud. Keep in mind that Mason Bees only travel in a radius of 100 yards from where they hatch, so they should be placed in the middle of the fruit orchard they are meant to pollinate. Due to their early emergence and short lifespan, Mason bees are usually only useful for pollinating fruit orchards.
The slow-moving, slightly humorous-looking bumblebees are one of the best pollinators in nature. Active during the majority of the growing season, they are used in commercial greenhouses to pollinate vegetable crops. Bumblebees grow to a size of 1/2 to 1 1/2 inches and are very furry, with a yellow and black striped color scheme. Attracting bumblebees is like attracting any other bee; just make sure you have flowers and plants that produce high amounts of pollen and nectar for them to feed on. Bumblebees especially like butterfly bushes and bee balm.
There are a multitude of other beneficial insects that attack not only specific pests, they also attack a wide range of other pests in your garden.