Garden Insects of North America: The Ultimate Guide to Backyard Bugs (Princeton Field Guides) - Hardcover

Cranshaw, Whitney

Hardcover

ISBN 10: 0691095604 ISBN 13: 9780691095608

Publisher: Princeton University Press, 2004

Synopsis

Garden Insects of North America is the most comprehensive and user-friendly guide to the common insects and mites affecting yard and garden plants in North America. In a manner no previous book has come close to achieving, through full-color photos and concise, clear, scientifically accurate text, it describes the vast majority of species associated with shade trees and shrubs, turfgrass, flowers and ornamental plants, vegetables, and fruits--1,420 of them, including crickets, katydids, fruit flies, mealybugs, moths, maggots, borers, aphids, ants, bees, and many, many more. For particularly abundant bugs adept at damaging garden plants, management tips are also included. Covering all of the continental United States and Canada, this is the definitive one-volume resource for amateur gardeners, insect lovers, and professional entomologists alike.


To ease identification, the book is organized by plant area affected (e.g., foliage, flowers, stems) and within that, by taxa. Close to a third of the species are primarily leaf chewers, with about the same number of sap suckers. Multiple photos of various life stages and typical plant symptoms are included for key species. The text, on the facing page, provides basic information on host plants, characteristic damage caused to plants, distribution, life history, habits, and, where necessary, how to keep "pests" in check--in short, the essentials to better understanding, appreciating, and tolerating these creatures.


Whether managing, studying, or simply observing insects, identification is the first step--and this book is the key. With it in hand, the marvelous microcosm right outside the house finally comes fully into view.

• Describes more than 1,400 species--twice as many as in any other field guide


• Full-color photos for most species--more than five times the number in most comparable guides


• Up-to-date pest management tips


• Organized by plant area affected and by taxa for easy identification


• Covers the continental United States and Canada


• Provides species level treatment of all insects and mites important to gardens


• Illustrates all life stages of key garden insects and commonly associated plant injuries


• Concise, clear, scientifically accurate text


• Comprehensive and user-friendly

About this title

About the Author

Whitney Cranshaw is Professor and Extension Specialist at Colorado State University, responsible for developing pest management programs for insect pests of horticultural crops. He is the author of two popular books, Pests of the West and Bagging Big Bugs.

From the Back Cover

"Garden Insects of North America is a tremendous contribution and is destined to be a staple on any gardener's bookshelf. Readers will find it overflowing with color pictures and informative yet easy-to- read descriptions. If this isn't the one book you must have, it comes pretty close!"--Casey Sclar, Integrated Pest Management Coordinator, Longwood Gardens

"Whitney Cranshaw's Garden Insects of North America is the most comprehensive book on insect and mite pests of vegetable, fruit, and ornamental plants now in print. Working from experience and the scientific literature, Dr. Cranshaw delivers information on a huge variety of pests in an entirely engaging manner."--James R. Baker, Professor Emeritus, North Carolina State University

"Whitney Cranshaw is probably the only entomologist who could pull off such a large undertaking! His clear, concise writing style, his completeness, and his attention to proper illustration will put this book ahead of any other in the field."--David Shetlar, Ohio State University

"A quick diagnostic tool for identifying pest insects by host plant, Garden Insects of North America will appeal to a wide audience, including home gardeners, master gardeners, entomologists in diagnostic clinics, and students."--Jody Fetzer, University of Minnesota Landscape Arboretum

Excerpt. © Reprinted by permission. All rights reserved.

Garden Insects of North America

The Ultimate Guide to Backyard Bugs

By WHITNEY CRANSHAW

PRINCETON UNIVERSITY PRESS

Copyright © 2004 Princeton University Press
All rights reserved.

ISBN: 978-0-691-09560-8

Contents

PREFACE, xi, 
ACKNOWLEDGMENTS, xiii, 
PHOTOGRAPHIC CREDITS, xv, 
CHAPTER ONE Introduction to Garden Insects and Their Relatives, 1, 
CHAPTER TWO Management Principles for Some Garden Pests, 26, 
CHAPTER THREE Leaf Chewers, 48, 
CHAPTER FOUR Leafminers, 204, 
CHAPTER FIVE Flower, Fruit, and Seed Feeders, 222, 
CHAPTER SIX Sap Suckers, 284, 
CHAPTER SEVEN Gall Makers, 408, 
CHAPTER EIGHT Stem and Twig Damagers, 434, 
CHAPTER NINE Trunk and Branch Borers, 460, 
CHAPTER TEN Root, Tuber, and Bulb Feeders, 500, 
CHAPTER ELEVEN Beneficial Garden Arthropods, 544, 
APPENDIX OF HOST PLANT GENERA AND ASSOCIATED INSECTS AND MITES, 577, 
GLOSSARY, 629, 
SELECTED REFERENCES, 637, 
INDEX, 639, 

CHAPTER 1

Introduction to Garden Insects and Their Relatives

With few exceptions, the animals covered in this book are all members of the phylum Arthropoda—the arthropods. As such, all share certain physical features, including:

• division of the body into segments;

• an external skeleton (exoskeleton) and growth that requires periodic shedding of the exoskeleton (molting);

• jointed appendages;

• internal structures that include a heart running along the upper (dorsal) part of the body and a nerve cord running along the lower (ventral) part of the body; and

• bilateral symmetry in body organization, i.e., similar on both sides.

Within the phylum Arthropoda are several subdivisions known as classes. Although this book concerns itself primarily with the class Hexapoda, which includes the insects, five other arthropod classes can also be found in yards and gardens—crustaceans, millipedes, centipedes, symphylans, and arachnids.

The primary exception to arthropods included in this book are the slugs and snails. These are mollusks, more closely related to clams and mussels than to insects. They are often included in the broad purview of "garden bugs," however, and thus are discussed here.

The classification of the animals in this book, to the order level, is summarized as follows.

Phylum MOLLUSCA - Mollusks
Class GASTROPODA - Slugs and Snails
Stylommatophora

Phylum ARTHOPODA - Arthropods
Class CRUSTACEA - Crustaceans
Isopoda - Pillbugs and Sowbugs

Class DIPLOPODA - Millipedes
Julida
Spirostreptida
Spirobolida

Class CHILOPODA - Centipedes
Lithobiomorpha - Stone Centipedes
Scolopendromorpha - Tropical Centipedes

Class SYMPHYLA - Symphylans
Scutigerellidae - Symphylans

Class ARACHNIDA - Arachnids
Opiliones - Daddylonglegs, or Harvestmen
Aranae - Spiders
Acari - Mites and Ticks

Class HEXAPODA - Hexapods (includes Insects)

METAMORPHOSIS

Because arthropods possess an external skeleton, they grow in distinct stages, each punctuated by a molting of the old exoskeleton and formation of a new, usually larger one. The stages between episodes of molting are known as instars.

During this growth process arthropods often undergo changes in form, a process known as metamorphosis. Sometimes these changes are minor, primarily involving an increase in size perhaps combined with changes in coloring or patterning. These changes can be more dramatic, however, particularly in insects as they approach the ultimate, adult form.

Broadly speaking, insects follow one of two general patterns of metamorphosis: simple metamorphosis or complete metamorphosis. Earwigs, grasshoppers, and aphids are examples of those that have a simple type of metamorphosis (see Figure 1). They have immature stages, known as nymphs or larvae, that generally resemble the adult and share many habits. In addition to a change in size, the nymphs may develop external features, such as wing pads, in transition to the adult. Adult insects differ from nymphs by being sexually mature and, if they are winged, have functional wings.

Much more specialization of function—and difference in form—occurs among the insects that undergo complete metamorphosis. The immature stages are collectively known as larvae, although larvae of many insects are so recognizable that they commonly go by another name such as grub, caterpillar, or maggot. Several larval instars often are similar in appearance, although they get progressively larger in size. At the end of the last larval stage they often move to some protected site and become inactive in preparation for transition to a unique stage known as the pupa. Tremendous changes take place during the pupal stage as larval features dissolve and are transformed into those of the adult. Among insects with complete metamorphosis, the appearance and habits of the adult may be very different from those of larvae. The overwhelming number of insects species are those that undergo complete metamorphosis and include beetles, moths and butterflies, flies, bees, ants, and wasps (see Figure 2).

Regardless of the type of metamorphosis, further development of external structures ceases once insects reach the adult form. Therefore a little fly is not a "baby" big fly or a tiny ant a "baby" ant. They are merely adults of a small species or were stressed through poor diet or some other factor during larval development.

HEXAPOD ORDERS

The hexapods share several features that separate them from the other arthropod classes. These include:

• division of the body into three main regions (head, thorax, abdomen);

• three pairs of legs, located on the thorax; and

• one pair of antennae.

Many also develop wings in the adult stage and thus are the only winged arthropods.

Two subdivisions (subclasses) of the hexapods are generally recognized. The overwhelming majority are Insecta, the insects. A small number of hexapod species are in the subclass Entognatha, which includes most prominently the springtails. Entognatha share many features more characteristic of crustaceans and thus are now commonly considered separate from the insects.

Currently, approximately 30 different orders of insects are recognized. Several are infrequently encountered in the yard and garden because of their small size, scarcity, or habits that restrict them to different environments, as in the aquatic insects. The orders and type of metamorphosis of the insects most likely to be seen in yards and gardens include the following.

IDENTIFICATION OF IMMATURE STAGES OF ARTHROPODS

Because of the changes that occur during development, arthropods change in appearance at different life stages. These changes are particularly dramatic in insects that undergo complete metamorphosis (e.g., beetles, moths and butterflies, flies). Often it is the immature stage (e.g., caterpillars, grubs) that causes most plant injury, as many larvae are specialized feeding machines. Adults may have very different form and functions (e.g., reproduction, dispersal). Thus, it can be difficult when observing insect activity to associate the adult and immature stages of the same insect.

The arthropod orders whose immature stages are most likely to be seen in yards and gardens are discussed below.

Coleóptera (Beetles)

Beetle larvae are often known as grubs. All possess strong jaws designed to chew, and the jaws may be quite prominent in species that chew wood or capture prey. The larval form is often elongated. Three pairs of legs on the thorax are clearly present among those species that actively move about aboveground or on the surface of plants (e.g., lady beetles, leaf beetles).

Grubs that develop belowground or within plants typically lose pigmentation and are pale colored, usually creamy white. For those that actively dig in soil, such as the white grubs, the front legs are well developed and may be used in digging. Many important groups of beetles develop within plants, however, and their larvae have lost all legs, leaving only the darkly colored head capsule as a conspicuous feature. The bodies of bark beetles and weevil larvae somewhat resemble pieces of puffed rice with a dark head. Flatheaded borers, larvae of metallic wood borers, are quite elongated and have a broad area on the first segment of the thorax. Roundheaded borers, larvae of longhorned beetles, are also quite elongated, with the dark prominent jaws distinguishing the head region.

Lepidoptera (Butterflies, Moths, Skippers)

Immature stages of lepidopterans are known as caterpillars. They possess three pairs of clawlike true legs on the thorax. Unlike most immature insects, however, they also possess fleshy leglike extensions, known as prolegs, on several segments of the abdomen. Each proleg is tipped with minute hooks, known as crochets, arranged in patterns characteristic of each family. All lepidopteran caterpillars can be distinguished from other insect larvae by the presence of two to five pairs of prolegs, each of which is tipped with crochets (see Figure 3).

The legs and prolegs of caterpillars that bore into plants (e.g., clearwing borers) may be very reduced. However, the presence of crochets always distinguishes them from other wood-boring insects.

Neuroptera (Lacewings, Antlions, and Relatives)

All neuropteran larvae are predators. Curved, lancelike jaws project prominently from the head. Larvae are active and possess legs on the thorax but no prolegs on the abdomen.

Hymenoptera (Ants, Bees, Wasps, Sawflies, and Relatives)

Rarely do gardeners encounter the larval stages of Hymenoptera. This is because they occur in colonies (e.g., social wasps, honey bees, ants), develop in specialized nest cells (e.g., hunting wasps, leafcutter bees), or are in plants (e.g., gall wasps). These larvae are usually very pale colored and have little pigmentation except around the mouthparts. A distinct head region is present but can be difficult to distinguish since there is little color difference.

Larval features are very different among some of the active leaf-feeding larvae, notably the sawflies. Sawfly larvae look quite similar to moth and butterfly larvae and similarly are often termed caterpillars. Like Lepidoptera larvae, sawfly larvae have prolegs on the abdomen, but the number is significantly different. Sawflies possess six to eight pairs of prolegs, and none have the hooklike crochets at the tip that characterize moth and butterfly larvae.

Diptera (Flies, Gnats, Mosquitoes, and Relatives)

Larvae of the "true flies" completely lack legs. Furthermore, many lack any distinct head area. Instead the head end is often tapered to a point and surrounds a pair of tiny hooks that are normally retracted. A pair of eyelike spiracles are commonly present on the hind end. This larval form is known as a maggot and is produced by flies in the suborder Brachycera (e.g., root maggots, house flies, flower flies).

Larvae in the suborder Nematocera (e.g., gnats, midges, mosquitoes) also lack legs but have a distinctly visible head capsule which often is darker than the rest of the body.

Thysanoptera (Thrips)

Most immature thrips (larvae) roughly resemble adults in body form, and the first stages often are found together with the adults on plants. (Late-stage larvae usually drop to the soil and undergo a non-feeding period where they experience some physical changes.) However, immature thrips lack wings and often have different coloration.

Hemiptera (True Bugs)

True bugs have a simple type of metamorphosis, and thus immature stages (nymphs) feed in a manner similar to the adults and share many other habits with them. Body form is generally similar, but nymphs lack the fully developed wings of the adults and are not sexually mature. Wing pads become increasingly prominent as the nymphs approach maturity.

Homoptera (Aphids, Psyllids, Whiteflies, Scales, Cicadas, Leafhoppers, and Relatives)

Homopteras undergo simple metamorphosis. In most families, immature stages roughly resemble adults except they lack wings. In some families, however, there can be unusual forms. In whiteflies and psyllids, nymphs are quite flattened and look very different than the winged adults. This is particularly true in whiteflies where there is a special nonfeeding transition stage (sometimes referred to as a pupa) immediately preceding the adult. The first stage following egg hatch among scale insects, known as the crawler, is highly mobile and little resembles the more sedentary later stages which produce a waxy cover. Similarly, the nymphs of cicadas are specialized for life belowground, whereas adults are winged and look substantially different.

Orthoptera (Grasshoppers, Crickets, Katydids)

Most features of immature and adult Orthoptera are similar. Only the adult has fully developed wings, however. Coloration and patterning among nymphs also commonly change with age. Wing pads are present on immature stages and become more prominent as maturity approaches.

Mantodea (Mantids)

Most external features of immature and adult mantids are similar except the wings. As mantids develop, the wing pads become increasingly prominent, with the wings becoming fully developed and functional only in the adult stage.

Dermaptera (Earwigs)

Most features of immature and adult earwigs are similar. The tail-like cerci on the tip of the abdomen and the wing pads increase in size as the insects mature.

Isoptera (Termites)

Features of almost all immature and adult termites are similar, differing only in size. Metamorphosis can be more flexible among these social insects, and some may develop into different castes (e.g., soldiers, reproductives) as colony needs determine. Reproductive forms possess large, functional wings in the adult stage and distinct wing buds in the early stages of development.

Collembola (Springtails)

All stages of springtails have similar external features and differ only in size.

Acari (Mites and Ticks)

Following egg hatch, all mites (except eriophyid mites) and ticks are minute and six legged, a stage known as a larva. After the first molt they transform into eight-legged immature stages and possess the general body form of the adult for the remainder of their development. Among spider mites there are two additional molts as they transform through the protonymph and deutonymph, ultimately reaching the adult form. Other mites may have an additional nymphal stage (tritonymph). Special inactive "resting stages" may occur with these groups of mites.

An unusual mite family is the eriophyid mites. These are minute, with an elongate, carrot-shaped form, and they possess only two pairs of legs in all life stages.

EXCRETED AND SECRETED PRODUCTS USEFUL IN DIAGNOSING GARDEN ARTHROPODS AND SLUGS

Honeydew. This is a sticky, largely sugary liquid excreted by certain insects that feed on the phloem of plants. It is produced by certain insects in the order Homoptera, including aphids, soft scales, whiteflies, mealybugs, and some leafhoppers. Because of its high sugar content, honeydew is highly attractive to ants, wasps, bees, and other insects. On surfaces where honeydew persists for long periods, it supports sooty molds; fungi similarly use honeydew for growth.

Fecal, or Tar, Spots. Dark fecal spots on foliage are associated with many plant-feeding insects that suck sap from the mesophyll of plants. These include thrips, lace bugs, and some leafhoppers, spider mites, and plant bugs. Because of the nature of the feeding, there is usually associated leaf spotting. The size of the tar spots is related to the size of the insects.

Spotting is also produced by most moths shortly after they emerge from the pupal stage. It is usually pale brown or reddish brown and is known as meconium. Syrphid flies, a common family of aphid predators, also leave dark smears of excrement on plants.

Frass. The solid excrement produced by insects that feed on solid foods is known as frass. Texture and consistency largely depend on diet; insects feeding on high-moisture foods produce soft and watery frass, whereas those feeding on dried wood or grain produce granular frass. In some species the frass may have a highly characteristic pattern or texture and can be a useful identification aid.

Silk. The silk found around plants is most characteristic of caterpillars such as leafrollers, tent caterpillars, and fall webworms which use silk to create shelters and tie together foliage. The webspinning sawflies also construct shelters of silk. Silk, formed into a cocoon, also surrounds the pupal stage of many moth larvae, sawflies, lacewings, and other insects.

Most spider mites produce visible silk, particularly when their populations are high. Spiders also use silk for many purposes. Most obvious are the webs some species use to snare prey. Other spiders use silk to form a "retreat" in which they hide when not foraging for prey. Also, almost all spiders use silk to cover egg masses.

(Continues...)

Excerpted from Garden Insects of North America by WHITNEY CRANSHAW. Copyright © 2004 Princeton University Press. Excerpted by permission of PRINCETON UNIVERSITY PRESS.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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Edition details

• Publisher: Princeton University Press
• Publication date: 2004
• Language: English
• ISBN 10: 0691095604
• ISBN 13: 9780691095608
• Binding: Hardcover
• Number of pages: 496