About This Guide

This field guide describes insects that occur in the Pacific Northwest, from southwestern British Columbia to northern California. Most of the species included are native to the Pacific Northwest region; the few that are not native are indicated as introduced in their accounts. Since insects do not recognize state or national boundaries, most of the insects in this book have ranges outside the Pacific Northwest.

There are at least 28,000 (and still counting) species of insects in the Pacific Northwest. We have included in this introductory guide 452 species in 10 orders (there are 30 orders worldwide, but not all occur in the region). And although this is basically a book about insects, we have also included 19 noninsect terrestrial invertebrate species for a sampling of interesting small creatures other than insects that the reader might likely encounter. The criteria Pete used to select the insects were that they had to be (1) common (a species likely to he seen by many people), (2) large enough to photograph well, and/or (3) distinct enough that they can be identified by a photograph. He also took into consideration the kinds of insects in which the public seems to be most interested. In his 33 years with county agricultural commissioner's offices, the insects most frequently brought into the office for identification have been almost exclusively common, large, distinctive beetles, butterflies, and moths. As a consequence, the number of species in this field guide is weighted in favor of a few orders, particularly Coleoptera (beetles) and Lepidoptera (butterflies and moths).

One criterion he did not consider as part of the basis forinclusion in this book was the economic or social value of an insect. Much literature in the past has described insects in terms of how they affect humans, either in a positive way because they prey on other insects, or in a negative way because they do harm to crops or the lives of humans or domesticated animals or have been simply seen as pests. Our intent is to present insects for their intrinsic value, as players in natural processes, without the good/bad label.

Pete has underrepresented or omitted several orders of insects, even some that are very common, for a variety of reasons. Some insect groups likely to be encountered in daily life, such as mosquitoes, termites, or ants, are very difficult to identify to species, and many of the species that are small in size cannot be adequately identified by photograph. Many introduced insects that are common, such as honey bees, are not covered because this book emphasizes native species. Some aquatic insects that are well known to anglers, such as caddisflies and mayflies, have been omitted because they are well covered in several books on flyfishing and in the scientific literature; such insects are important to salmon and trout fisheries, but no more important than, say, dragonflies, which are included in this guide. Few household and garden "pests" are dealt with in this book because information about these species is often presented in cooperative extension pamphlets and books on pest control. The economic impacts of insects considered to be agricultural pests are discussed in other books that specifically deal with these species as pests; many of these pest species are nonnative (they have been introduced from Europe and Asia), and, again, this is not a book about pests.

The focus of this guide is the identification of insects (and some non-insect invertebrates). In order to make this guide easy to use, especially for the non-scientist, Pete has used photographs as the basis for the format, with picture-based keys. All the photographs in this field guide were taken with a single lens reflex (SLR) camera, usually handheld with no flash. The slide film used was ISO 50 or 100. All but a few of the photographs are of live insects and taken in the field.

Also for the sake of simplicity, we have attempted to keep the entomological jargon to a minimum. The few entomological terms that we determined needed definition are located in the glossary. However, unlike other field guides that primarily use common names for insects (and non-insect invertebrates), this guide is based on scientific names. We have emphasized scientific names because, as stated previously, they are standardized and more reliable than common names, and many of the insect species in this book do not have a common name or names.

Even so, the scientific name, as well as the classification, of a species may be different depending on which source the reader uses. Name changes can be very frustrating, and perhaps discouraging, to the non-scientist. We have tried to present the most recent classification and the most recent and most commonly used scientific and common names; for the most part, the classification and names used in this field guide are based on Nomina Insecta Nearctica: A Check List of the Insects of North America edited by R. W. Poole and P. Gentili.

The identification portion of this book is separated into two parts, one on the insects and the other on the non-insect terrestrial invertebrates. Within these sections, the groups of species are organized alphabetically, first by order, then by families within the order, and lastly by species within the family. Thus the arrangement of species presented here does not follow a hierarchical type of classification system. The orders are preceded by a picture key to the orders, and each order composed of more than a few families has a picture key to the families within that order (Note: the size of a family or genus refers to the number of species within that family or genus.)

The account for each species is accompanied by a photograph of one or more of its life (developmental) stages and/or a structure (for example, plant gall) associated with it. For many of the species, particularly those of moths and butterflies (order Lepidoptera) and stink bugs (family Pentatomidae, order Hemiptera), Pete has included the immature stage(s) because, in most cases, one is just as likely to find this form of the species as one would the adult; a case in point is moth larvae, which are more likely to be seen than the adults since the adults of many moth species fly at night. Also, during certain times of the year, one can find the larva but not the adult.

Each species account is organized as follows. First is the species name, that is, the scientific name for the species. Although we have provided the most current scientific name, be aware that the name is not written in stone and hence maybe different in other literature. A common name(s) may also be listed under the species name: a species may have multiple common names or none at all. The common name we give is generally the most widely used English name for the species in the literature.

Next follows a description of the distinguishing field marks of one or more life stages of the invertebrate, or, in the case of insect species that induce the formation of galls, the structure of the galls. The description is generally limited to those characteristics that we feel will help the reader identify the insect. If a life stage is not listed, it maybe for one of the following reasons: (1) it is the stage least likely to be encountered in the field, (2) there may be little difference between adult and nymph, or (3) we did not find any information on that stage. This field guide uses the common practice found in other insect field guides, particularly those on butterflies and moths, of indicating the dorsal and ventral sides of an insect's body or wings as "above" and "below," respectively.

Body length and wingspan are the measurements commonly used to indicate the size of an invertebrate. Body length, used for invertebrates other than adult moths and butterflies, is the linear measurement in millimeters from the front of the animal's head (not including antennae) to the tip of its abdomen (not including terminal appendages). This measurement applies to the adult stage of the animal unless otherwise noted. For adult moths and butterflies, this book employs the common practice found in other field guides of using wingspan to compare the sizes of the different species of moths and butterflies. Wingspan is the linear measurement in millimeters from tip to tip of the outstretched forewings. This section may include the length, width, or height of galls.

The food source of one or more life stages (for example, adult, larva) of the species is given next. If a stage is not listed, we did not find any information regarding the food source or the animal does not feed at that stage. The common name (if any) and scientific name of host plants are listed.

The "found" section presents the general distribution of the species in the Pacific Northwest region (and may also indicate distribution outside the region). This part of the account may also include microhabitat information. Additional information about the species, including other scientific or common names of the species that might be encountered in other books, may be provided at the end of the account.

Searching for Insects

Insects can be found almost everywhere; however, certain habitats are more likely to yield a larger number and a wider variety of insects. The best places to look are on plants, where most insects will probably be found on the flowers and leaves; others may be on or in the stem, bark, wood, roots, or inside galls or the fmits or seeds of flowering plants.

Some species of insects can be found on the ground, in leaf litter, under the bark of dead or dying trees or logs, or under debris such as stones and boards (if these objects are moved, they should be carefully put back where they were found). Other species can be found on or in fungi, dung, or decaying plant or animal material. Many insect species live in or near water, either their entire lives or only during certain stages of their lives.

Although different insect species are active at different times of the year, the best time to look for the adults is usually early spring until late fall, when most plants are in bloom. Pete tries to time his search to coincide with where the flowering season is at its peak. He starts by looking for insects in late winter/early spring in areas that warm up first, which are usually near rivers or other bodies of water in inland valleys. Next, he goes to coastal areas, and then, as the season progresses, to higher elevations. After the flowering season peaks and summer turns into fall, insects can still be found in riparian areas and in other places that have late-flowering plants or lush foliage.

Different species can also be found at different times of the day, but flying insects are usually more active during the warmer periods of the day. Some species of flying insects, such as moths and lamellicom beetles, come out during warm nights.

In order to identify insects, amateur as well as professional entomologists have traditionally captured them to be preserved as specimens in collections. Although collecting insects is the best way to identify them, it is becoming more common to observe and identify insects in their natural habitats while disturbing them as little as possible. To this end, close-focusing binoculars are an essential tool. This type of binoculars is capable of focusing quickly and on objects less than 6 feet away. A pair of 7×35 binoculars is usually adequate for most field observations.

Another piece of equipment that is excellent for use in identifying insects is the camera. Although preserving a specimen is the best way to have a permanent record of a species, taking a photograph of an insect is not only an accurate way of identifying most species but also a way of documenting a species without directly impacting it. Although Pete's camera of choice has been a single lens reflex (SLR) camera with a macro lens, he now considers a digital camera to be better. Digital cameras are lighter in weight and cheaper to purchase and to maintain; they do not need film, and the photographs can be immediately evaluated as to quality and then directly downloaded to a computer.

Good fieldwork requires additional tools. Those Pete carries into the field include a knife for prying up bark or digging into wood, soil, or other such media in which insects may hide; a hand lens for examining insects close-up; plant as well as insect field guides; and a notebook for recording such basic items as species name, host plant(s), date, and locality (he also may include such data as weather conditions, type of habitat, and insect behavior). Also handy to have are a small metric ruler and a pair of forceps, for manipulating dead insects or ones that may sting or bite.

If Pete has to capture an insect in order to identify it, he usually does so by hand. In addition to this method, there are several pieces of equipment one can use. One item that the public usually associates with entomologists is what is commonly referred to as the "butterfly net." This type of net, with the more accurate name of aerial net, is not only used to catch butterflies but other flying insects as well. Aerial nets are usually lightweight, durable, and have a bag made of fine-meshed material that is easy to see through. To capture non-flying insects, another type of net, called a sweep net, is used to beat or brush through vegetation. These nets have a bag made of canvas or heavy muslin. Whether caught by hand or by net, insects should be handled gently and with respect.

If an insect needs to be collected, but kept alive, to confirm its identification, it should be transported in some kind of a container: the best are made of hard plastic — Pete uses empty film containers for most insects. It is very important to transport the field containers in an ice chest (with ice), especially in hot weather, because the cold causes the insect to become torpid and, consequently, it is less likely to be injured. More detailed information about the methods and equipment used for collecting and preserving specimens is readily available in other sources.

Insects and Native Plants

Most of the insects in this field guide are native to the Pacific Northwest, and, as a result, most depend on native plants directly or indirectly for their survival. Increasingly, areas of native vegetation are being consumed by urban and suburban landscapes, where usually most, if not all, the native vegetation has been replaced with buildings, asphalt, and ornamental (that is, non-native) plants. Consequently, native wildlife populations, including those of insects, have been greatly reduced or extirpated in these areas.

There are efforts to reverse or at least mitigate this trend, and there is a growing awareness of how important a part the native insect fauna plays in these native landscapes.