The Good Bugs in the Garden: Attracting Beneficial Insects
Where the Good Bugs Eat the Bad Bugs
A healthy garden is a mini-ecosystem where beneficial insects, birds, bats, toads and other animals provide natural biological controls against many common pests. Infestations of bad bugs can become problematic because many gardeners do not provide the right environment to attract these natural predators. Inviting beneficial insects and predators into your backyard to take up permanent residence helps with keeping the numbers of pests in check and under control without the need for harmful poisons and expensive pesticides.
Most gardeners instantly recognize a lady beetle or a praying mantis and welcome these hungry predators into their gardens to feast on aphids and other bad bugs. But there are many other beneficial garden insects and animals that are not quite as cute or as easily recognized as friendly allies to gardeners. Encouraging spiders, dragonflies, damselflies and other beneficial insects into your garden will help improve nature's balance between predator and prey while adding to the diversity, beauty and interest of your gardens and landscapes.
Attracting Beneficial Insects to the Garden
Avoid Broad Spectrum Pesticides
Most pesticides do not discriminate between pests and beneficial bugs. Applying broad spectrum poisons to your plants can wipe out the predator insects as well as the intended targets.
Killing off the beneficial insects also opens up the garden to a re-infestation of pests as new populations of bad bugs move in from the surrounding areas. Instead of using commercial pesticides, consider using organic controls such as a blast of water from a garden hose to remove aphids from the underside of leaves or hand-picking slugs and caterpillars from plants.
Oils and insecticidal soaps are also effective in targeting soft-bodied insects such as aphids. If chemical control is needed, be careful to use pesticides that are targeted towards the specific bad bugs that are attacking your plants.
Not Every Bug is a Pest. Look Before You Squish!
Add Beneficial Host Plants
Many common landscape plants provide food and shelter for beneficial bugs during the different phases of their life cycle, and this is especially true of many native flowering perennials and shrubs. Mixing in ornamental plants such as sunflowers, coreopsis, coneflowers and milkweeds with edible plantings and adding extra herbs, including dill and parsley, provides beneficial bugs with shelter and places to lay their eggs.
Where space permits, allow a section of the yard to grow naturally to encourage native weeds and grasses to grow and to further increase the diversity of beneficial garden insects.
Target Only the Pests
Not every bug is a pest, so take the time to learn the differences between the beneficial bugs and the harmful insects in your garden. Not all creepy looking bugs are pests; centipedes and soldier beetles (commonly called the stink bug) have voracious appetites for soft-bodied beetle larva, cut worms and mites. Learning to identify and target the bad insect pests before indiscriminately eliminating any of the beneficial garden insects will provide a healthier environment for your plants.
Leave the Leaves
After the fall frosts kills off the last of the blooms, let the leaves, seed pods and stalks of perennials stay uncut through the winter months. Many beneficial garden insects over-winter in the leaf litter, including spiders and many types of beetles.
Don't clean out the perennial beds until after the first warm days of early spring, giving the good bugs a chance to break out of their winter dormancy and start searching for a meal.
Increase Your Tolerance
The good bugs offer efficient and effective biological pest control without resorting to pesticides, but they cannot eliminate all of the pests in the garden. Some level of tolerance is needed by gardeners to accept minor leaf damage from pests in a balanced environment. We also should learn to co-exist with the spiders, beetles and other beneficial garden insects and critters that are essential residents in a healthy ecosystem.
Who are the Beneficial Insects?
The Good Bugs in the Garden
Predatory insects are the beneficial garden insects seeking out prey to satisfy their voracious appetites. Though some of the good guy bugs are visually unappealing and even downright scary looking, their presence in your garden means that the bad bugs are around and on the menu.
The Praying Mantis is a formidable predator, searching through the foliage for moths, flies, grasshoppers and other insects. Named for the the way the mantis holds its front legs in a folded position that resembles hands held in prayer, these insects have killer claws equipped with spikes for capturing and securing their prey.
Praying Mantis are typically green or brown in color, and they are well camouflaged for life in the leaves. With their large eyes perched on a triangular head that rotates 180 degrees, a mantis will often remain motionless for extended periods of time while scanning the surroundings for its next meal.
Praying Mantis are one the best beneficial bugs to help gardeners who don't want to use dangerous chemicals to control the insect pests in their garden. They are one of the most versatile of predator insects, eating just about any bug that they can catch.
The ladybug's familiar round, bright red shell spotted with black dots is a welcome sight to gardeners. Favored by children everywhere for their colorful shells and docile demeanor, ladybugs are also appreciated by gardeners for their fierceness in eating soft-bodied insect pests.
Ladybugs are specialists, feasting on the plump little aphids that siphon juices out from the leaves of tender plants. A female ladybug lays her eggs on aphid-infested plants, and as soon as the eggs hatch, the hungry ladybug larva begin to feed voraciously on aphids. Over the course of its lifetime, a ladybug can consume up to 5,000 aphids.
Also known as the lady beetle, and in Europe as the ladybird beetle, ladybugs have over 5,000 species worldwide and over three hundred different species in North America.
Release Live Ladybugs Into Your Garden
Ladybugs eat aphids, mealy bugs, scale, leaf hoppers, and other destructive pests. They prefer to eat aphids and will devour up to 50 a day, but they will also attack scale, mealy bugs, boil worm, leaf hopper, and corn ear worm. And they keep on eating until the bad guys are gone, laying their own eggs in the process. When new pests arrive, the next generation of hungry ladybugs will be waiting.
Ladybugs are available commercially through many online retailers, and they travel well through the mail. Plan on releasing your new arrivals in the evening, preferably on a calm evening without a lot of wind. Ladybugs will not fly at night, and they will look for a sheltered spot to rest until the next morning. Water the plants in the release area prior to setting the bugs free. After a long trip through the mail, the ladybugs will need to quench their thirst.
Dragonflies and Damselflies
One of the oldest families of insects on the planet, dragonflies and their ancestors have been around for over 300 million years. Dragonflies are typically found near water, where they lay their eggs in ponds and streams. After hatching, the young nymphs feast on mosquito larva before the adult dragonfly emerges to take flight. Airborne, dragonflies target mosquitoes and moths that are caught and devoured while in flight.
Despite their fearsome look, dragonflies and damselflies are harmless to humans and are welcomed visitors to our pond and garden.
Predatory and numerous, lacewings are found worldwide. The brown and green lacewings are the most common species, feeding on soft-bodied insects as larva and also as adults (though the adults green lacewings will also feed on the nectar of plants). Combined with their relatively long lifespans of up to 3 months, lacewings are beneficial predatory insects that help to keep populations of mites, aphids and white fly nymphs in check.
Centipedes are typically found in moist environments, hiding under rocks and boards in the garden. Though they do not actually have a hundred legs, centipedes move quickly through the mulch and leaf litter in search of prey. Centipedes are carnivorous and eat a variety of insects, injecting their invertebrate prey with venom before devouring their victims.
Centipedes are best left alone as their bite can be painful to humans. The venom is not harmful to people, but it can cause allergic reactions similar to bee and wasp stings.
There is nothing more beautiful than a large web, glistening with dew in the early morning sunshine. But for the unwary insect, the sticky web of a garden spider brings certain death.
Garden spiders are not technically insects, but rather belong to the Arachnid family. Insects have six legs and a three-part body, whereas spiders have eight legs and a two-part body. Large garden spiders look intimidating, but though they have fangs and can bite if provoked, their bite is harmless to humans.
There are many different types of garden spiders. Some species of garden spider spin marvelous circular webs up to two feet across, while others hunt along the ground in search of unsuspecting bugs. Spiders eat all kinds of insects, including moths, flies, beetles and grasshoppers—just about any insect that gets tangled in their silky webs.
Parasitic wasps are a very specialized predator: rather than capturing prey for their young to eat, a parasitic wasp inserts its eggs into the body of an unsuspecting insect host such as the hornworm caterpillar—the fat green caterpillar commonly found munching on the leaves of tomato plants.
As the young wasp larva hatch, they begin to feed on their host. Eventually, they emerge to spin a silky cocoon that is anchored on the back of the doomed caterpillar.
Parasitic wasps are tiny, harmless to humans and often go unseen in the garden, but they make their presence known by the number of caterpillars carrying around little white cocoons on their back. If you find a tomato worm covered in little bits of white, remove the caterpillar by hand and relocate to another part of the yard. The wasps will finish the job, and the next generation of wasps will seek out more unsuspecting victims.
Organic Gardening Poll
How do you contol pests in your garden?
Beneficial Garden Insects In Action: Attack on the Tomato Horn Worm
How To Make A Toad House
Make a Toad House
Toads are welcome visitors to the garden, and a toad house invites them to stay. Offering protection for the weather and from predators, a toad house is easy to make from an inverted terracotta flower plot. Topped with a mossy roof, a toad house is a simple yet artful additional to our shade garden.
Gently chip out a small opening in the rim of an 8" terracota flower pot using a hammer or pliers. The terracotta is both tough and brittle, and it is difficult to break cleanly. Try to chip out a semi-circular opening about 2 inches across, though the size and shape is not critical. Cement the back of the saucer to the top of the inverted pot using an exterior adhesive, or simply place on top of the inverted flowerpot.
Fill the saucer with potting mix, and press pieces of moss into the soil. Keep the moss moist until it takes root in the soil. Over time, the moss will crept over the edges of the saucer.
Place the finished toad house in a shady area of the garden, near groups of perennials or near the base of a small shrub. Bury the rim into the soil to stabilize the pot. The decorative toad house is ready for new tenants.
Invite Other Wildlife into the Garden
Toads, bats and birds all feed on different insects and pests, and are easily encouraged to visit gardens of nearly every size. Bats eat hundreds of moths and mosquitoes every night, toads eat slugs and cut worms, and different types of birds feed on numerous caterpillars, bugs and beetles.
Provide a water source such as a small pond to entice predatory damselflies and frogs. In some areas, owls and even snakes help to control the populations of destructive moles and voles.
Certify Your Backyard Wildlife Habitat
The National Wildlife Federation Certification Program
For over 35 years, the National Wildlife Federation (NWF) has encouraged homeowners, schools, corporations and municipalities to incorporate the needs of the local wildlife into their landscape design. So far, the NWF has recognized the efforts of nearly 140,000 individuals and organizations who plant native shrubs and plants for food, cover and places for raising their young, provide include a source of drinking water, and add nesting boxes for cavity nesting birds.
Please visit the NWF website for additional information on their official Certified Wildlife Habitat program.
Let It Bee (and Spiders, Birds and Toads)
Questions & Answers
© 2011 Anthony Altorenna