Free Naturally Bug-Free by Anna Hess

Chapter 1: Pest-invertebrate identification
    I was concerned when I saw the dark scales above on dead asparagus stalks, but I soon realized these were simply eggs of the innocuous katydid that sings me to sleep on autumn nights.
     
    My first rule when dealing with garden insects is to identify everything I see. Many new gardeners assume every bug is bad, but the truth is that a significant number of the creepy crawlies you'll find on your vegetables are either random passers-by, are beneficial pollinators, or are predators of leaf nibblers. The trick is to know the difference, and to understand how larger animals fit into the complex web of garden life. While this book can't introduce every garden character, I can at least hit the highlights and help you find the resources to fill in gaps on your own.
     
    Types of invertebrates
    The most common types of invertebrates visible to the naked eye in a garden are annelids (worms), molluscs (snails and slugs), myriapods (centipedes and millipedes), arachnids (spiders and mites), crustaceans (sowbugs and crawdads), and insects.
     
    When setting out to identify an unknown garden resident, it's handy to have a framework to fit them into. Most critters you'll find in your garden are known as invertebrates because they have no backbone. (I incorrectly call them "bugs" throughout this book when I'm not feeling very scientific.) The chart above shows the wide range of invertebrates you can find in most backyards.
    In the next section, I'll introduce you to the worst garden pests in the U.S., but what should you do if your leaf nibbler isn't on that list? When I find an unknown denizen of the garden, I usually start my identification campaign with the internet. If you go to www.images.google.com and type in some identifying features, your pest's mugshot may pop right up. For example, when I saw my first asparagus beetles, I typed in "orange beetle on asparagus," and the species I was looking for turned up on the first row.
    It's particularly handy to know the main types of invertebrates because a good search often includes the category of invertebrate, its color, and the plant the bug is found on. The picture at the beginning of this section introduces you to the major types of invertebrates found in a garden: annelids, molluscs, myriapods, arachnids, crustaceans, and insects. Among insects, the most common categories are beetles (with hard wing covers), flies (with only one pair of flight wings, the other wing pair having been reduced to knobs), true bugs (with sucking mouthparts and including cicadas, aphids, leafhoppers, and shield bugs), grasshoppers and their kin (including crickets and katydids), butterflies and moths (and the caterpillars that are their larvae), hymenoptera (ants, bees, and wasps), and dragonflies (along with the related damselflies). If you can tell these major groups of insects apart, you'll be well on your way to identifying the next unknown bug in your garden.
     
    It's handy to be familiar with each stage of an insect's life cycle. The photos above all show Mexican bean beetles: eggs, a larva, and an adult.
     
    If a simple image search fails, I turn to books next. Garden Insects of North America by Whitney Cranshaw is my favorite invertebrate field guide because its full-color photos usually help me narrow down my search quickly. Several other field guides to garden insects (or just to insects in general) exist as well, and any of these titles will help you identify your garden friends and foes.
    But sometimes books fail me as well. At that point, I usually turn to www.bugguide.net, which is the Wikipedia of the invertebrate world. You can often identify an invertebrate (or at least get close) by working your way through bugguide's key, but if I'm thoroughly stumped, I instead log in and submit a photo, requesting identification help. One of the volunteers gets back to me within a day or two, telling me which species (or category) of invertebrate I've found.