Friday, May 09, 2014
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From the Spring Home and Garden magazine: "OUT OF THE ORDINARY"

A short list of beneficial garden insects

By Jim Youngquist

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[May 09, 2014]  It's the end of April, almost May, and the weather is turning warm. With the first spark of warmth, bugs begin to emerge from wherever they have been hiding from the winter's cold, and they begin to do what they do best: BUG YOU!

We are constantly surrounded by insects, and they compete with us for just about everything. There are insects that bite on us and some that suck our blood. There are insects that eat our food, eat our crops and even eat our homes. And if you aren't creeped out yet, there are even bugs that live on our skin.

Even though they are all creepy and alien-looking, not all insects and bugs are our enemies. There are a few that actually benefit mankind, especially in the garden, and recognizing them and promoting their colonies can help us reduce the amount of pesticides we use, protect our crops and animals, and be more healthy.


10. The ladybug

In Logan County we are well aware of the presence of ladybugs, especially if you live anywhere near a farm field. Ladybugs, also called lady beetles and ladybird beetles, spend their whole lives eating the bugs that eat our plants, especially aphids and whiteflies. Ladybugs come in both orange and red dotted varieties. They begin their lives hatched from eggs to become small, alligator-shaped larvae. Here in the county, we also have those Asian ladybugs that were imported to specifically eat the aphids and scale insects that infect soybean fields; we know those because they bite us, too!

Regular ladybugs are so good at controlling plant pests that you can buy them by the half-pint from companies such as Planet Natural  approximately 4,500 ladybugs for $26.

9. The green lacewing

The common green lacewing adult doesn't do much for people, but their kids are the real heroes. The kids, known as "aphid lions," eat many different garden pests, including aphids (which suck the life out of plant leaves and stems), mealybugs and thrips. You can also buy green lacewing eggs from Planet Natural at

8. Fly predators

Besides mosquitoes, the insects that bug us the most have to be FLIES. Swat them, spray them, even trap them, and there are always more flies than we can control, especially late in the summer.

Happily, there is a tiny, parasitic wasp called the zaraptor that controls flies by laying its eggs in the fly maggots. The eggs hatch and eat the fly pupae from the inside out. You can order the zaraptor wasps from

7. The Trichogramma

With a $10 name, the Trichogramma is also a tiny, parasitic wasp, but this one lays its eggs in the eggs of more than 200 species of butterflies and moths  you know, the ones that are pretty when they are flying around but nasty when they are munching the leaves of your vegetable garden plants, such as the infamous cabbage worm. The Trichogramma last only nine to 11 days, but during their short life they short-circuit the caterpillars that devastate our flower and vegetable gardens.

6. Predatory mites

The sixth on the most-wanted list combats a pest that is difficult to control and eradicate: spider mites. Spider mites can damage garden plants and indoor plants, and they are an especially damaging greenhouse pest. Predatory mites eat the eggs of spider mites and help control outbreaks. Consider spraying with insecticidal soap prior to releasing predatory mites, to give them a leg up.

5. Whitefly parasites

Whiteflies can quickly get out of control in a garden, especially if there is less than average rainfall. Both the adult and young whiteflies dwell on the undersides of leaves, and the adults fly off when disturbed, making a white cloud of tiny flying insects. When you reach the cloud state, your garden is in serious condition. Whiteflies are especially attracted to verbena, lobelia and tomato plants. The most effective biological control for the whitefly is another of the tiny, parasitic wasps, called Encarsia formosa. Old formosa is attracted to the scent of the honeydew produced by aphids and whiteflies, and it feeds on the body fluids of both adult and larval whiteflies.

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4. Mealybug destroyers

Mealybugs are gross and nasty. They make small nests that resemble white, cottony patches on the leaves and stems of our garden and indoor plants. Inside those gooey patches, the mealybugs hide, lay their eggs and suck the life out of our plants. The mealybug destroyer is a small, reddish-brown beetle with dark brown wing covers. They get to be only about a fifth of an inch long. They voraciously feed on aphids, scales and especially mealybugs in the greenhouse, interior plantscapes, orchards and ornamental gardens.

3. Predatory nematodes

Living in moist, dark environments, predatory nematodes are the dragons of the insect world. Predatory nematodes are merely microscopic in size, but they attack and kill almost all pest insects.

Beneficial or predatory nematodes hunt at the root zone, in the thatch of lawns, around the crowns of garden plants and even up into corn tassels. Being so small, predatory nematodes burrow into invading insect pests and eat them out from the inside. More details about predatory nematodes are available at

2. Damsel bugs

These sleek predators stalk their prey all over the plant, from root to flower, and devour aphids, small caterpillars, thrips, leafhoppers and other pesky, detrimental bugs. Damsel bugs are often collected from farm fields with insect nets and moved to the home garden.

1. The praying mantis

The praying mantis is a very interesting bug. And they get quite large up to 5 inches long at maturity. They are beneficial to humans because they grab and eat just about any insect that is in their path. They look like something from another planet. Kids love watching this quirky insect and often collect them and feed them bugs in a jar. The praying mantis is the king of predatory insects because they are so voracious. You can buy their egg cases at

A final note about using beneficial insects:

Beneficial insects are our friends because they eliminate the bad bugs. In order to let them do their job, we need to first become familiar with them and not squash them like a pest under our shoes or between our fingers (ick) when we see them. And, like all insects, they are killed by the same pesticides that kill insect pests. So, when we use predatorial insects to help maintain our gardens, we need to hold back the bug-killing sprays that we used to use. The best approach is to use more than one kind of beneficial insect to help control the pests.

If you have an interest in knowing more about beneficial insects and the environment, watch for programs at Creekside, the new Lincoln College Outdoor Center for Environmental Education. Dr. Dennis Campbell, an environmental enthusiast, oversees the center, which includes an insectarium.



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