Well over 100,000 species of insects and other arthropods are known to exist in North America, and the scope of this book is necessarily limited. Emphasis herein is on those “garden bugs” that are most likely to be encountered in a yard and garden, particularly those that injure plants. Selecting which insects, mites, and other “garden bugs” to include—and perhaps more importantly which not to include—has involved many judgment calls. For example, many insects restricted primarily to forests, grasslands, waters, or other natural areas overlap in their presence and activity in yard and garden settings.
In this second edition of Garden Insects of North America a great many changes have been made. Perhaps most obvious is the greatly increased number (and quality) of images, reflecting the enormous changes that have occurred with photography of insects since 2004. But the number of species included in this edition has also greatly expanded. This expansion has occurred throughout the book, but some sections are either completely new or have been given greatly expanded treatment. This new treatment is particularly evident in chapter 8, which discusses natural enemies of insects and mites along with important pollinator species of bees.
The expanded treatments in this second edition have been made possible by making this a coauthored publication, involving the complementary experiences of both Whitney Cranshaw and David Shetlar.
ORGANIZATION
Garden Insects of North America is designed to provide a means to identify the types of insects one might find in a yard and garden and to diagnose their presence based on associated symptoms they may produce on plants. To best achieve this approach, we adopted an organization that is a hybrid of ways that other books on insect identification are organized. In Garden Insects of North America the primary groupings involve the parts of plants where one might most often notice insects. For examples, chapters 2 and 3 cover insects found on leaves and needles, chapter 4 the insects that occur on twigs, stems, and canes, and chapter 5, insects associated with larger branches and the trunks of trees. Chapter 6 covers the broad subject area of insects, mites, and other arthropods one might see feeding on roots, at the soil level, or developing within the soil. Chapter 7 deals with insects and mites found in or on flowers, fruits, seeds, and nuts. Chapter 8 has a different focus, covering the natural enemies of insects and one group of important flower-visiting pollinators, the bees.
Within these main chapters, the associated insects (and other garden “bugs”) are usually organized by taxa, to the genus level whenever appropriate; however, we have made an effort to place insects together in the text that have somewhat similar appearance or habit. For example, mealybugs are placed near related groups such as “woolly” aphids and soft scales. Also, the caterpillars of many families of moths and skippers form protective shelters of silk, frass, or leaf fragments, or combinations of these, and these are grouped. At the end of each section, classification to the order and family level is noted. For example, following discussion of the peach tree borer there is the notation “Lepidoptera: Sesiidae” to indicate that the peach tree borer is in the order Lepidoptera (moths and butterflies) and the family Sesiidae (clearwing borers).
The diversity of insect habits clearly defies easy grouping. For example, western corn rootworm develops as a root-feeding larva on corn plants, then feeds on leaves and flowers of a wide variety of plants as an adult. Japanese beetle is a first-class problem in turfgrass, where it develops underground as a white grub, but later as an adult that feeds on leaves and flowers of many garden plants. Such “crossover” species are treated primarily in one section (western corn rootworm as an insect that develops on plant roots, Japanese beetle as an insect that chews on leaves), but where such insects occur there are cross-references and treatments in other chapters.
COMMON NAMES
Throughout the book we often use common names, concurrently defined with a scientific name (genus, species). When we decided to use a common name, we always gave precedence to names accepted by the Entomological Society of America, which has a long-established procedure for formalizing common names of insects. For many insects and their relatives, however, there are not yet any officially recognized common name. Where this occurs, often one or more names have been proposed in other publications. Some of these are used in this book. Ultimately all such common names should be formally proposed and, where acceptable, recognized by the Entomological Society of America and Entomological Society of Canada.