Insects 101

Insects often get a bad rap. Their virtues (and amazing feats) are rarely discussed. Most people assume an insect is guilty until proven innocent. But understanding insects better cultivates trust in nature's plan for pest control and allows you to intervene where it really makes a difference. So in case you've hardened your heart against insects, here are intimate details of the fascinating (and endearing) interactions among several common garden inhabitants.They're InsatiableEveryone knows the ladybug (ladybird beetle), but few would recognize either her eggs or the larvae which hatch from them. Surprisingly, the larvae do much more good than the adults. The bright yellow eggs are oval and are laid standing on end in clusters of 10 to 20, in crevices of bark or underneath a leaf. Ladybugs often lay eggs on plants that aphids frequent -- a wise move, since aphids are the larvae's favorite chow. The young larvae have tapered, highly segmented bodies less than a half-inch long and sport tiny tufts of hair and six legs. They are slate-colored, with red-orange markings. These lizard-shaped creatures are born starving and can put away up to 40 aphids per hour. If you find them wandering around looking for something to eat, transfer them to where they're needed. After a few weeks of cleaning up your garden, they hang themselves up by their tails, form a protective case, and transform into an adult ladybug. Since the adult is no longer growing, it requires less food; however, it's still helpful in the garden. Every year, ladybug larvae cause a lot of confusion. They're constantly brought into nurseries by alarmed gardeners who assume they're destructive, and want to know how to kill them. The ladybug is a rare exception in the world of creepy-crawlies -- a well-loved insect. Its good reputation is upheld by the fact that it (and especially its larvae) eats aphids, and the eggs of many insects, including the Colorado potato beetle. And where are the good ladies now that it's cold? Having formed a layer of insulating fat under their wings, they take off to the mountains, where they hibernate in groups numbering in the thousands in moist crevices. (They retreat to the mountains in very hot, dry weather, as well.) When they awaken, their instincts compel them to fly until this layer of fat dissolves. This is why it's not too effective to buy those little bags of ladybugs at the nursery. You open the bag, and they all fly away. Furthermore, companies which sell them often harvest and deplete wild populations. It's better to wait for the ladybugs to find your garden, which they will, no matter where you live.Even HungrierThe golden-eyed lacewing has fragile, almost transparent wings and a pale green body hardly more than a half-inch long. Its antennae point forward while large, brassy eyes stare to either side. The female lacewing lays her oval, greenish (later whitish) eggs in an unusual fashion -- each stands upright on a long, thread-like stalk, resembling a miniature lollipop. The reason? If the eggs were clustered, the first voracious larva out would eat all the other eggs. These characters resemble ladybug larvae in basic form but are all brown and have "giant" piercing jaws like miniature alligators. Aphid lions, as they are sometimes called, top ladybug larvae in aphid consumption (clocked by a motivated entomologist at 60 per hour), and they have a taste as well for mites, thrips, leafhoppers and assorted insect eggs. You won't get to watch this one, though: The aphid lion hides by day and feeds by night. After almost two weeks of relentless feasting and a couple of molts, the larva makes a pearly, pea-sized cocoon. Two weeks later, the dainty, attractive lacewing emerges. Leaving its aggressive past behind, it flutters about looking for a mate, sips nectar and nibbles on pollen -- a complete transformation. The lacewing (larva) is considered one of the best beneficial insects for the greenhouse or garden.Ants Complete the ScenarioBut let's get the whole story here. We can't talk about lacewings and ladybugs without talking about ants, because they compete for the same food source -- aphids. There are some varieties of ants which thrive on the aphid's honeydew (their sweet excretions after sucking plant sap). These ants are sometimes referred to as "pastoral." Like shepherds, they keep flocks of aphids, defend them from attack, and kill the aphids' parasites. Ants will even carry aphids from place to place, and protect aphid eggs in their nests over the winter, bringing them out again in the spring. What do the ants get in return for their security services? When an ant gently strokes an aphid with its antennae, the aphid responds by excreting a drop of honeydew for the ant.So if aphids are a problem in your garden, you probably have an ant problem as well. I once observed ladybugs approaching a cluster of aphids guarded by ants, and the ants knocked the ladybugs off the twig! Get out your magnifying glass and tune into the dramas in your yard instead of the ones on the Discovery Channel.How to Give Beneficials the EdgeHere 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 a habitat for all insects, the "good" ones vastly outnumber the "bad" ones. However, if any plants had 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, to take the proper action, you need to know whether the eggs you've found will become ladybugs or Colorado potato beetles. * Limit the use of pesticides to biological controls (such as BT) which affect only the target pest. 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.Cultivate CuriosityAside from ladybugs and lacewings, there are countless other friendly insects in the garden. Some I've yet to meet are robber flies, minute pirate bugs, soldier bugs, ambush bugs and assassin bugs. (Judging from their names, their lives must be dramatic.) While I'm not suggesting that all pest problems go away by themselves, there is a lot of help out there. As I learn more about insects, fearful distrust has given way to curiosity and appreciation, and a hesitation to meddle unthinkingly with scenarios I don't fully understand. Thanks to Linda Wiener for generous research assistance and entertaining stories.Carole Tashel looks forward to meeting lots of new bugs next year.Resources To learn more about beneficial insects, send for the highly informative Green Methods Catalog ($8.95): 93 Priest Rd., Nottingham, N.H. 03290-6204, (603) 942-8925.

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