One key to garden health
is to imitate the diversity
of the original ecosystem.

The Beautiful Balance of Bugs

Carole Tashel

n the gardens of our dreams, bugs don't bother our plants. So when they do show up, it's natural to want to get rid of the problem pronto, with one application of a foolproof product. The strongest pesticides (like Diazinon and Sevin) do indeed make bugs drop dead, but not without exacting a heavy price from birds, bees, earthworms, lizards and other living things.

Just as important, even though chemicals appear to work, they usually make the original problem worse: insecticides are agents of natural selection that weed out susceptible individuals, creating new generations of aggressive, invincible "superbugs." When chemicals kill both "bad" and "good" bugs, this eliminates the organisms that would help solve the original problem and often results in a secondary outbreak of yet another unwanted insect.

The last thing we want to do when we interact with our garden is to perpetuate a sense of struggle against natural forces (like insects). Instead, it's best to work on decreasing plant stress (from heat, wind, etc.) and improving soil quality and moisture levels. As Eliot Coleman put it in the November/December 1998 issue of Organic Gardening: "Our current pest-control thinking is 180 degrees backwards. We should focus on the insusceptibility of plants rather than focus on killing pests. This approach can be defined as plant positive — in contrast to the present approach, which is pest negative. . . . It's not a question of whether pesticides are undesirable or not. The fact is that they are superfluous."

Yes, Nature actually has her own plan for pest control, and it's a good one.

Why you should manage, rather than wipe out, pests

With summer in full swing, it's safe to say that plenty of bugs are showing up in your garden. What to do when aphids are covering that new rosebush or hornworms are crawling all over your tomato plants? First, don't panic. Take a minute to understand how bugs work in your garden, how your garden hosts the good and the bad, and how you may be able to play one off against the other and, in the longer term, produce healthier, more productive plants.

Some background is helpful. Whenever we scratch the surface of an undisturbed natural system, a rich tapestry of interdependent relationships is revealed. Take Santa Fe 200 years ago: ample trees (pi ñon, juniper, etc.), diverse ground covers and grasses, shrubs (Apache plume, saltbush, winterfat, mountain mahogany and others), intact soil organisms, and a great variety of insects, mammals, birds and reptiles.

One key to garden health is to imitate the diversity of the original ecosystem. Sadly, native vegetation is a frequent casualty of development or careless ranching. The earth is stripped, compacted and later eroded, and weeds form a scab on the disturbed soil. Insect and animal communities disappear, creating an imbalance between insects and their predators.

Enter the home owner desiring a beautiful landscape and/or productive vegetable garden, asking, "Why are these bugs ruining my plants?" The vast majority of infestations occur because something is wrong — poor soil, improper plant placement, shallow watering, and the absence of beneficial (predatory) insects are just a few possibilities.

Returning to our aphid-covered rosebush . . . ordinarily, the aphid's worst enemy should have taken care of the problem. (Have you hugged your ladybugs today?) Ladybugs eat not only aphids, but also many other unwanted insects, leaving behind the beneficial ones. There are lovely plants that attract ladybugs: buckthorn, euonymus, yarrow, butterfly weed, tansy, "Lemon Gem" marigolds and almost all herbs.

Then there are creatures that encourage aphids. Ants, for example, protect aphid colonies from predators while feeding on the honeydew the aphids produce. I once observed ladybugs approaching a cluster of aphids guarded by ants, and the ants knocked the ladybugs off the twig! To control aphids, you must also discourage the ants.

Consider too that "harmful" insects aren't all bad: many actually draw beneficial insects to our gardens. Take hornworms, for instance. It works like this: A hornworm finds your tomato, then tiny parasitic wasps sniff out the worm, laying eggs in its body (or in the worm's eggs); this ends the hornworm's career. More than that, a few so-called bad bugs stress the plants just enough to make them stronger. And leaf damage of up to 30 percent can actually increase the yield of some vegetable crops. Which is why so many experts now prefer "managing" rather than wiping out pests. Don't automatically assume an unknown bug spells trouble. Only slightly over 10 percent of all insects cause lasting damage.

Getting bugs to eat each other instead of your plants

Sucking, chewing, gnawing, drilling, nibbling . . . it's alarming when bugs trash your treasured plants. But don't lose heart — invite (or purchase) "beneficial insects" to go to work for you.

It's astonishing, but more than half of all insects are predators or parasites of other insects. For appetizers, many of them enjoy nectar and pollen, same as bees and butterflies; for their main course, they dine on the bugs that are bugging you — aphids, grubs, cutworms and mites, to name a few. It's a good bet many of these great bugs are already hard at work in your yard.

Just like other living creatures, helpful bugs appreciate moisture, crave protection from wind and sun, and look for safe places to lay their eggs. By planting a multitude of shrubs, trees and perennials, as well as lots of small-blossomed herbs and wildflowers, you give these insect allies what they need — and may even persuade them to become permanent residents.

Many useful insects are minuscule; the old reliable petunias and snapdragons are too big for them to negotiate and contain relatively little pollen. Experiment instead with the parsley family (dill, Queen Anne's lace), the mints (thyme, peppermint, lemon balm), the sunflower family (yarrow, calendula, coreopsis, tansy, cosmos), and buckwheats (sulphur flower). Try to have at least one plant in flower from spring through fall.

Everyone's favorite garden helper is the ladybird beetle (ladybug). During the 20 days her larvae are maturing, they gobble up hundreds of aphids and have a taste for scales, whiteflies, thrips, leafhoppers and mites. Adults don't eat as much; they're too engrossed with mating and laying loads of eggs. Happily, adults can sometimes winter over in the garden.

But don't stop at ladybugs. Who'd suspect flies to be part of the cast of good guys? Tachinid flies, which resemble bristly houseflies, lay eggs that wind up inside unlucky hosts (tomato worms, many caterpillars, cutworms, even grasshoppers). The tiny Trichogramma wasp (it does not sting pets or people) has a ravenous appetite for upward of 200 pests, including the cabbage worm, hornworm, corn earworm and borer, cutworm and codling moth. The wasp's larvae munch the eggs of unwanted pests, and your problem never materializes.

Some consider the delicately beautiful green lacewing, dubbed the "aphid lion," to be the best all-around predator. For up to 20 days, as the larvae mature, they devour aphids, red spider mites, thrips, immature scales and whiteflies, and the eggs of many worms. What about the entertaining praying mantis? Bad news. Turns out her appetite is small and undiscriminating — she eats beneficial bugs (and her mate) right along with a few beetles and tent caterpillars. Don't rely on her as your mainstay. And there's still more. . . . Squash borers eating your lunch? Bulbs and perennials gnawed by root maggots or grubs? Cutworms got you down? Beneficial nematodes (microscopic threadlike worms) can come to the rescue.

Insects aren't the only critters worthy of praise: Spiders and toads graze mostly on bothersome bugs, and lizards love ants. House wrens feed hundreds of caterpillars to their young. Bluebird moms offer grasshoppers to their fledglings and adore cutworms and mosquitoes. Flickers snack on a thousand ants. And this is only a fraction of what happens behind the scenes in a healthy garden.

It's funny, but gardens should have bugs. All kinds. (Otherwise, the natural pest patrol won't stick around.) So relax and let the garden function naturally. Not that there's nothing to do: Handpick pests early to keep large numbers from overwhelming your predators. Learn to accept minor damage. Note successes and failures for next year. Practice waiting for the weather to change. Even bugs have their seasons — if ladybugs haven't polished off all the spring aphids, then the hot weather will. And remember, it's a bug-eat-bug world.

Excerpted from Gardening the Southwest: How to care for your land while growing food, beauty and medicine by Carole Tashel. Available from the author and at some local nurseries. The section "The Beautiful Balance of Bugs" contains resource listings for beneficial insects and nontoxic/biological controls.

How to Give Beneficial Insects the Edge

Here are some garden practices to help beneficial insects keep damaging insects in check. (Vegetable gardens may require further interventions that are beyond the scope of this article.)

• Mulch generously. Though mulch provides habitat for all insects, the "good" ones vastly outnumber the "bad" ones. However, if any plants have an insect problem, it's good garden hygiene to remove mulch and fallen leaves from underneath these plants at season's end. This prevents eggs or adults from overwintering.

• Inspect the garden regularly. If you find unfamiliar insects or eggs, get them identified before doing anything. For instance, you should know whether the eggs you've found will become ladybugs or Colorado potato beetles.

• Limit the use of pesticides to biological controls (such as Bacillus thuringiensis, or Bt) that affect only the target pest. Remember, even plant-based pesticides like rotenone and pyrethrum kill good bugs.

• Don't disturb spiders or their webs. Spiders are unquestionably beneficial — all of them.

• Plan for a continuous supply of flowers in bloom. Ladybugs and lacewings (and many other insects like the highly beneficial tiny parasitic wasps) require nectar and pollen. Three flowers good bugs like the best are Queen Anne's lace, yarrow and fennel; others include dill, cilantro, alyssum (one of the few early spring bloomers), coneflower and anything in the mint family.




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	One key to garden health is to imitate the diversity of the original ecosystem. The Beautiful Balance of Bugs Carole Tashel n the gardens of our dreams, bugs don't bother our plants. So when they do show up, it's natural to want to get rid of the problem pronto, with one application of a foolproof product. The strongest pesticides (like Diazinon and Sevin) do indeed make bugs drop dead, but not without exacting a heavy price from birds, bees, earthworms, lizards and other living things. Just as important, even though chemicals appear to work, they usually make the original problem worse: insecticides are agents of natural selection that weed out susceptible individuals, creating new generations of aggressive, invincible "superbugs." When chemicals kill both "bad" and "good" bugs, this eliminates the organisms that would help solve the original problem and often results in a secondary outbreak of yet another unwanted insect. The last thing we want to do when we interact with our garden is to perpetuate a sense of struggle against natural forces (like insects). Instead, it's best to work on decreasing plant stress (from heat, wind, etc.) and improving soil quality and moisture levels. As Eliot Coleman put it in the November/December 1998 issue of Organic Gardening: "Our current pest-control thinking is 180 degrees backwards. We should focus on the insusceptibility of plants rather than focus on killing pests. This approach can be defined as plant positive — in contrast to the present approach, which is pest negative. . . . It's not a question of whether pesticides are undesirable or not. The fact is that they are superfluous." Yes, Nature actually has her own plan for pest control, and it's a good one. Why you should manage, rather than wipe out, pests With summer in full swing, it's safe to say that plenty of bugs are showing up in your garden. What to do when aphids are covering that new rosebush or hornworms are crawling all over your tomato plants? First, don't panic. Take a minute to understand how bugs work in your garden, how your garden hosts the good and the bad, and how you may be able to play one off against the other and, in the longer term, produce healthier, more productive plants. Some background is helpful. Whenever we scratch the surface of an undisturbed natural system, a rich tapestry of interdependent relationships is revealed. Take Santa Fe 200 years ago: ample trees (pi ñon, juniper, etc.), diverse ground covers and grasses, shrubs (Apache plume, saltbush, winterfat, mountain mahogany and others), intact soil organisms, and a great variety of insects, mammals, birds and reptiles. One key to garden health is to imitate the diversity of the original ecosystem. Sadly, native vegetation is a frequent casualty of development or careless ranching. The earth is stripped, compacted and later eroded, and weeds form a scab on the disturbed soil. Insect and animal communities disappear, creating an imbalance between insects and their predators. Enter the home owner desiring a beautiful landscape and/or productive vegetable garden, asking, "Why are these bugs ruining my plants?" The vast majority of infestations occur because something is wrong — poor soil, improper plant placement, shallow watering, and the absence of beneficial (predatory) insects are just a few possibilities. Returning to our aphid-covered rosebush . . . ordinarily, the aphid's worst enemy should have taken care of the problem. (Have you hugged your ladybugs today?) Ladybugs eat not only aphids, but also many other unwanted insects, leaving behind the beneficial ones. There are lovely plants that attract ladybugs: buckthorn, euonymus, yarrow, butterfly weed, tansy, "Lemon Gem" marigolds and almost all herbs. Then there are creatures that encourage aphids. Ants, for example, protect aphid colonies from predators while feeding on the honeydew the aphids produce. I once observed ladybugs approaching a cluster of aphids guarded by ants, and the ants knocked the ladybugs off the twig! To control aphids, you must also discourage the ants. Consider too that "harmful" insects aren't all bad: many actually draw beneficial insects to our gardens. Take hornworms, for instance. It works like this: A hornworm finds your tomato, then tiny parasitic wasps sniff out the worm, laying eggs in its body (or in the worm's eggs); this ends the hornworm's career. More than that, a few so-called bad bugs stress the plants just enough to make them stronger. And leaf damage of up to 30 percent can actually increase the yield of some vegetable crops. Which is why so many experts now prefer "managing" rather than wiping out pests. Don't automatically assume an unknown bug spells trouble. Only slightly over 10 percent of all insects cause lasting damage. Getting bugs to eat each other instead of your plants Sucking, chewing, gnawing, drilling, nibbling . . . it's alarming when bugs trash your treasured plants. But don't lose heart — invite (or purchase) "beneficial insects" to go to work for you. It's astonishing, but more than half of all insects are predators or parasites of other insects. For appetizers, many of them enjoy nectar and pollen, same as bees and butterflies; for their main course, they dine on the bugs that are bugging you — aphids, grubs, cutworms and mites, to name a few. It's a good bet many of these great bugs are already hard at work in your yard. Just like other living creatures, helpful bugs appreciate moisture, crave protection from wind and sun, and look for safe places to lay their eggs. By planting a multitude of shrubs, trees and perennials, as well as lots of small-blossomed herbs and wildflowers, you give these insect allies what they need — and may even persuade them to become permanent residents. Many useful insects are minuscule; the old reliable petunias and snapdragons are too big for them to negotiate and contain relatively little pollen. Experiment instead with the parsley family (dill, Queen Anne's lace), the mints (thyme, peppermint, lemon balm), the sunflower family (yarrow, calendula, coreopsis, tansy, cosmos), and buckwheats (sulphur flower). Try to have at least one plant in flower from spring through fall. Everyone's favorite garden helper is the ladybird beetle (ladybug). During the 20 days her larvae are maturing, they gobble up hundreds of aphids and have a taste for scales, whiteflies, thrips, leafhoppers and mites. Adults don't eat as much; they're too engrossed with mating and laying loads of eggs. Happily, adults can sometimes winter over in the garden. But don't stop at ladybugs. Who'd suspect flies to be part of the cast of good guys? Tachinid flies, which resemble bristly houseflies, lay eggs that wind up inside unlucky hosts (tomato worms, many caterpillars, cutworms, even grasshoppers). The tiny Trichogramma wasp (it does not sting pets or people) has a ravenous appetite for upward of 200 pests, including the cabbage worm, hornworm, corn earworm and borer, cutworm and codling moth. The wasp's larvae munch the eggs of unwanted pests, and your problem never materializes. Some consider the delicately beautiful green lacewing, dubbed the "aphid lion," to be the best all-around predator. For up to 20 days, as the larvae mature, they devour aphids, red spider mites, thrips, immature scales and whiteflies, and the eggs of many worms. What about the entertaining praying mantis? Bad news. Turns out her appetite is small and undiscriminating — she eats beneficial bugs (and her mate) right along with a few beetles and tent caterpillars. Don't rely on her as your mainstay. And there's still more. . . . Squash borers eating your lunch? Bulbs and perennials gnawed by root maggots or grubs? Cutworms got you down? Beneficial nematodes (microscopic threadlike worms) can come to the rescue. Insects aren't the only critters worthy of praise: Spiders and toads graze mostly on bothersome bugs, and lizards love ants. House wrens feed hundreds of caterpillars to their young. Bluebird moms offer grasshoppers to their fledglings and adore cutworms and mosquitoes. Flickers snack on a thousand ants. And this is only a fraction of what happens behind the scenes in a healthy garden. It's funny, but gardens should have bugs. All kinds. (Otherwise, the natural pest patrol won't stick around.) So relax and let the garden function naturally. Not that there's nothing to do: Handpick pests early to keep large numbers from overwhelming your predators. Learn to accept minor damage. Note successes and failures for next year. Practice waiting for the weather to change. Even bugs have their seasons — if ladybugs haven't polished off all the spring aphids, then the hot weather will. And remember, it's a bug-eat-bug world. Excerpted from Gardening the Southwest: How to care for your land while growing food, beauty and medicine by Carole Tashel. Available from the author and at some local nurseries. The section "The Beautiful Balance of Bugs" contains resource listings for beneficial insects and nontoxic/biological controls. How to Give Beneficial Insects the Edge Here are some garden practices to help beneficial insects keep damaging insects in check. (Vegetable gardens may require further interventions that are beyond the scope of this article.) • Mulch generously. Though mulch provides habitat for all insects, the "good" ones vastly outnumber the "bad" ones. However, if any plants have an insect problem, it's good garden hygiene to remove mulch and fallen leaves from underneath these plants at season's end. This prevents eggs or adults from overwintering. • Inspect the garden regularly. If you find unfamiliar insects or eggs, get them identified before doing anything. For instance, you should know whether the eggs you've found will become ladybugs or Colorado potato beetles. • Limit the use of pesticides to biological controls (such as Bacillus thuringiensis, or Bt) that affect only the target pest. Remember, even plant-based pesticides like rotenone and pyrethrum kill good bugs. • Don't disturb spiders or their webs. Spiders are unquestionably beneficial — all of them. • Plan for a continuous supply of flowers in bloom. Ladybugs and lacewings (and many other insects like the highly beneficial tiny parasitic wasps) require nectar and pollen. Three flowers good bugs like the best are Queen Anne's lace, yarrow and fennel; others include dill, cilantro, alyssum (one of the few early spring bloomers), coneflower and anything in the mint family.