Beneficial Insects
Here are a few tips to attract beneficial insects to you garden and make them feel welcome:
Don’t use pesticides. Pesticides rid your garden of many beneficial insects which are necessary for a healthy garden. Instead, attract predatory insects and other animals, such as birds, into your garden and make them welcome with a favorable habitat. Then let them control any pesky bugs. Plant a variety of flowering plants, especially ones with small flowers rich in nectar. Although many insect larvae are predators, a diversity of flowering plants will supply the nectar and pollen necessary to many of the adult forms, as well as provide safe places for resting and laying eggs. You may kill the insects that are helping you keep pests in check. This means you will have to spray more in the future. Also, insects benefit your garden by pollinating your plants, helping them grow and propagate.
Intercrop. Mix up your plants so those that attract beneficial insects are nearby those that need protection. Place your plants in the ground, or in tubs and pots, close together to provide a moist, shaded environment for beneficial insects who dehydrate easily. Provide a source of water for beneficial insects by putting out a shallow dish of water with stones to allow them dry places to land. Plant ground covers to provide shadowy, sheltered spots for spiders (they are also our friends in the garden). Keep your soil healthy by adding compost to allow soil organisms to thrive.
Provide food supply. Beneficial insects are more likely to remain in your garden if there is a ready food supply. While you can buy many of these predators, it's probably cheaper and more effective to encourage the ones already in your garden. Many beneficial insects need to sip flower nectar to survive. Plan your garden to feed beneficial insects by choosing a variety of plants that will bloom as many months of the year as possible. Here are some things you can do to support your beneficial insect population. Plant nectar-producing flowers to further increase the food supply. Plants in the cabbage, carrot and sunflower family are especially attractive to beneficial insects. Control ants, which may prevent predators from controlling aphids.Cover bare dirt in your garden with mulch of dead leaves or grass clippings, thick enough to shade the soil surface. This provides shelter for spiders, which are the number one predator on insects. (Most of these spiders are tiny.) Don't forget the birds. Birds can also be very helpful with controlling pests in your garden. Trees, shrubs with berries, birdhouses and water features all encourage birds to visit your yard.Attract beneficial insects to your yard rather than buying and releasing them. Releasing insects may rid your yard of naturally occurring beneficials through competition and predation (some beneficial insects, such as praying mantises, feed on both pests and other beneficial insects). In addition, some insects, such as certain ladybugs, are migratory and, once released, they quickly move on to other locations.
BENEFICIAL BUGS
LADYBEETLES
Lady beetles (ladybugs) are among the most visible and best known beneficial insects. Most adult lady beetles are round to oval, brightly colored and often spotted. The immature or larvae stages, however, look very different and often are overlooked or misidentified. Lady beetle larvae are elongated, usually dark colored, and flecked with orange or yellow. Both the adult and their dark gray and orange marked larvae feed on aphids (40-50 per day) and a wide variety of other soft-bodied pests, mites and eggs.
One group of small, black lady beetles (Stethorus) is important in controlling spider mites and others specialize in scale insects. Lady beetles can rapidly control many developing insect problems, particularly if temperatures are warm. One species of lady beetle, however, the Mexican bean beetle, is a plant pest. It is distinguished from other lady beetles by spotting and color in the adult stage. Larvae of the Mexican bean beetle are yellow and spiny.
After a few days of feeding, female ladybugs will deposit their eggs in small yellow clusters under a leaf or stem. The number of eggs laid depends on the availability of aphids, and the eggs are laid near pest populations. Within a week the eggs hatch into tiny alligator shaped larvae that join their “parents” feeding on many insect pests. After about 3 to 4 weeks the larvae will pupate and one week later the young adult beetles will emerge, ready to feed. Ladybird beetles generally have one to two generations per year, depending on season length.
PRAYING MANTIS
The fascinating praying mantis gets its name from its motionless raised front legs, which it uses to hold its prey. A ferocious predator, it will attack just about any insect in its path; unfortunately this includes other beneficial insects.
Praying mantis egg cases usually take two to three weeks of warm temperatures to hatch. The tiny mantises force themselves through the narrow slits of the eggs and immediately disperse into the foliage. One egg case will yield approximately 50 to 200 adults. Unless you can find the small nymphs, it is impossible to tell if the eggs have actually hatched. In 5 or 6 months, they reach their full size and females will deposit 1 to 5 egg cases on bushes and flower stalks. The female dies shortly after this. Mantis egg cases overwinter and hatch out in the spring, completing the life cycle.
LACEWINGS
The common green lacewing is a widely used beneficial insect which naturally controls many different pests. Actually, the adult stage of this beneficial does not kill other insects but subsists on pollen, sweet nectar, etc. It is their offspring, lacewing larvae, that do the job. The adult lays her eggs on the foliage, each on the top of hairlike filaments. After a few days the lacewing eggs hatch and a tiny larvae emerges, which is also known as the “aphid lion” due to its voracious appetite
Lacewing larvae are similar in appearance to an alligator with pincers like tiny ice tongs, and vigorously attack their prey, injecting a paralyzing venom, then drawing out the body fluids of the victim. Besides aphids, they feed on just about any soft-bodied pest they can “grab,” including citrus mealybugs, cottony cushion scale, spider mites, thrips, caterpillars, insect eggs, etc. It is known to be cannibalistic if no other food source is available. During the two to three weeks in this stage it will devour up to 200 victims a week. After this, it will pupate by spinning a cocoon with silken thread and approximately five days later the adult emerges to complete the life cycle.
TRICHOGRAMMA WASPS
Trichogramma Wasps are among the smallest insects, having a wingspread of about 1/50th of an inch. Despite its size, this beneficial insect is an efficient destroyer of the eggs of more than 200 species of moths and butterflies which are leaf eaters in the larval (caterpillar) stage. Trichogramma seek out eggs, but do not feed on or harm vegetation. It is a particularly effective control agent because it kills its host before a plant can be damaged. Some moth eggs attacked by trichogramma are: armyworm, bagworm, European corn borer, peach borer, squash borer, cankerworm, alfalfa caterpillar, cutworm, corn earworm, wax moth, tomato hornworm, cabbage looper, and codling moth.
During her 9-11 day life, the female wasp will seek out and destroy about 100 pest eggs by laying an egg inside of it. As the tiny parasites develop inside they consume the contents. Depending upon climatic conditions a new adult will emerge in about a week. The short life cycle allows the parasite population to increase rapidly.
MINUTE PIRATE BUGS
The minute pirate bug has a distinctive sucking beak and an insatiable appetite. It consumes large amounts of thrips, spider mites, scale (including whitefly), aphids, leafhoppers and the eggs and initial-larval stages of many soft bodied insects such as small caterpillars. Adults and nymphs feed by piercing pests with their "beak" and sucking out the body fluids. The victims shrivel after being eaten, becoming difficult to see on plants.
Adult minute pirate bugs are very small (1/8" long), somewhat oval-shaped, and black with white wing patches. Females lay tiny eggs within plant tissues where they are not easily seen. These hatch into nymphs, the immature feeding stage. Nymphs are small, wingless insects, yellow-orange to brown in color, teardrop-shaped and fast moving. Growth from egg to adult takes about 25 days. Several generations may occur during a growing season.
Found in gardens and growing areas throughout North America, these beneficial insects are attracted to alfalfa, sweet clover, vetch and daisies.
MEALYBUG DESTROYER
The adult mealybug destroyer is a small black lady beetle with a tan front end and a voracious appetite for mealybugs and some soft scales and aphids. Originally introduced into the United States in 1891 from Australia by one of the early biological control pioneers, Albert Koebele, this beneficial insect is credited with the complete control of the citrus mealybug. Both adult and larval stages are predatory.
Mealybug destroyers lay eggs among the cottony egg sack of mealybugs. Eggs hatch into larva in roughly 5 days. These larva, which are similar in appearance to the pest, feed on mealybug eggs, young crawlers, and the honeydew produced by pests. It takes approximately three weeks for these young predators to go through three larval stages and a pupal stage before they become adults. Four days after emerging, adult females begin to lay eggs and can lay as many as 400 eggs over their two month life span.
SPINED SOLDIER BUG
Common throughout the United States, the spined soldier bug is an extremely efficient predator of over 100 insect pests, including the larvae of Mexican bean beetle, European corn borer, diamondback moth, corn earworm, beet armyworm, fall armyworm, cabbage looper, cabbageworm, Colorado potato beetle and flea beetles.
Spined soldier bugs feed by penetrating their prey with a harpoon-like proboscis and sucking out the insects body fluids. Adults are highly mobile and will walk or fly rapidly throughout garden areas. Nymphs can quickly move from plant to plant.
Each adult female lays several hundred gray, cream, or gold barrel-shaped eggs in tight clusters of 20 to 30 on leaves and twigs. The nymphs initially cluster around the hatched eggs, then disperse to feed. There may be two to three generations per year. Adults can live up to 3 months.
SYRPHID (HOVER) FLY
This large family of flies, also known as hover flies, are important biological controls in many crops. The adults, resembling yellow jackets, are important pollinators, while the brownish or greenish caterpillar-like larvae have an appetite for aphids, beetles, caterpillars, sawflies, and thrips. Hover flies are often mistaken for bees or wasps because they have similar yellow and black markings. Hover flies cannot sting. Adults are pollinators, but the immature maggots are predators. They are pale, greenish brown and eat aphids, leafhoppers, scale insects, mealybugs, thrips, corn borers or corn earworms. One hover fly maggot will eat 400 aphids!
TACHNID FLY
Most tachinid flies attack caterpillars and adult and larval beetles, although others specialize on sawfly larvae, true bugs, grasshoppers, or others. These predators are important insects for the control of natural and introduced pests.
GROUND BEETLE
Ground beetles are one of the most common groups of beetles in North America. Adults vary in size from less than 1/8" to over one inch long. They are usually dark and shiny, although some species can be brightly colored. Nearly all adults and larvae are predaceous on other insects and are considered beneficial. While shapes and colors may vary widely, they are usually shiny. Some are very ferocious-looking, but they are not known to bite people. Black is a common color, sometimes with a metallic sheen of another color on their wing covers. Most ground beetles feed at night and hide in the soil or under debris during the day. Adult beetles range from 1/8 to one inch long. These very common garden insects feed on many soil-inhabiting pests such as cutworms and root maggots. Some types eat slugs and snails. You probably don't need to attract these common beetles. Unless it's discouraged with pesticides, the species that is right for your garden will find you. Low-till gardening techniques can save the lives of many soil-dwelling ground beetles. Objects to hide under, such as logs, boards or flat stones, will help keep ground beetles in your garden.
DRAGONFLY
They are relatively large and colorful, associated with water during every stage of their life, and are especially valuable because they eat mosquito larvae and adults. Dragonflies will not bite or sting humans, but they are voracious predators of small insects, including midges, mosquitoes, small moths, bees, butterflies or other dragonflies.
DAMSEL BUGS
Adult damsel bugs are 3/8 - 1/2" long, tan to reddish brown and slender, with the body tapering toward the head. Both the nymphs and adults are predatory and feed on a variety of prey. Almost any insect that is smaller or slower is subject to attack, including other predators.
SPIDERS
Spiders aren't insects at all. They can be identified by their eight legs and two-part body. Although there are hundreds of species of spider in Washington, they all share this trait. Spiders are far more beneficial than they are dangerous. Most spiders are shy and harmless to humans Spiders are the most important predators on insects, killing more than all other predators combined. They feed on a broad variety of pest insects year-round You probably already have an abundance of spiders. You can provide spider habitat by covering bare dirt with mulch, creating a "wild" area in your yard, planting dense shrubs and coniferous trees, and providing a water source such as a pond.If you are concerned about spiders in your home, sealing off your living space from the crawlspace, garage, floor voids and unfrequented storage space will help. House spiders and outdoor spiders are not the same species.
YELLOW JACKET
Adult wasps are 1/2 to 3/4 inch long, with characteristic yellow and black stripes and transparent wings Yellow jackets and other wasps are predators of caterpillars, flies and beetle grubs. Yellow jackets are often feared for their sting, which is a hazard to people who are allergic. Some yellow jacket species are more likely to sting and scavenge at picnics than others. The scent of pears is a sting signal for yellow jackets. To occupy yellow jackets during a picnic, place raw meat or a fish head away from the picnic (over a bucket of soapy water).
Think about that nest in your yard: Does it really have to go? If the yellow jackets are not interfering with the lives of people in the area, leave the nest alone and get great pest-control and pollination benefits.
