Colorado State University Cooperative Extension, Bulletin 506A
Colorado State University Cooperative Extension, Ft. Collins, CO
2000, pp. 283, Paperback
ISBN 1-889143-04-9

This is the most recent version of this useful reference for pests of woody plants. As the authors explain in the Acknowledgments, this publication has evolved from a reference for Colorado insect pests of trees and shrubs to a more comprehensive reference that now addresses insect, disease, and vertebrate pests of woody plants over a wider geographic region.

Comprehensive publications of good quality are valuable references for those who diagnose pest problems. I would strongly recommend the addition of this book to the reference shelf of extension agents and specialists, forestry professionals, nurserymen, arborists, landscape managers, and others who are asked to recognize pest problems of trees and shrubs, even if an individual is working outside the Central Rockies.

The book is organized at the top level by the portion of the plant affected such as foliage, branches and twigs, larger branches and stems, fruiting structures, and roots. Organization below this level follows taxonomic groupings (insects, diseases) keeping discussions from pest to pest flowing in a natural order. Many of the people who will find this reference most useful will be looking for the section that addresses the question or problem at hand. The table of contents provides a quick reference to those specific pest problems when the identity is known. Listing the insects, diseases, and other pests or disorders by common name makes the table of contents user friendly for the layman. In addition, the hierarchy of the outline is easy to follow through the table of contents.

A very useful section is the addition of a diagnostic key to the common woody plant disorders. The key is organized by plant identity, followed by affected area, descriptions of symptoms, and finally the likely cause with a page reference. The diagnostic key is located at the end of the book, after the index. When problem solving, this key will be very useful for identifying that less than familiar problem or providing a list of possible causes at a quick glance. The key probably deserves more favorable placement in future revisions, perhaps moving it to the front of the book. Maybe the authors have had the same experience as I, often going to the index in the back to find the topic and page number needed at the moment. The key’s utility, wherever located, will be a valuable tool to the user.

The authors have compiled a wealth of information that is presented in a concise fashion. The insect discussions include reference to host plants, descriptions of damage and diagnosis, summary of the life history and habits, and comments about management. Management does not include reference to specific insecticides which would date the book quickly. The authors recommend obtaining companion references that provide this information. The management section does address other considerations such as natural control agents, cultural management, organic alternatives, and general insights about the pest’s importance.

Descriptions of the insect and damage are brief, allowing the color photographs to compliment the narrative and assist in verification of identifications. This is fine in most cases but could be a hindrance when trying to communicate descriptions of insects during conversations without the benefit of visuals. Size descriptions are not included for all insects, requiring the user to have some familiarity with the insects where this information is lacking. The collection of photographs is very extensive. Anyone who has attempted to compile even smaller collections of graphics will appreciate the authors’ efforts. The publication layout has placed all photos to the outside edges of pages in a 2.25 inch (5.5 cm) wide column. This decision has necessitated the sizing of all photos to fit this constraint. The result for some photos is a size that makes some details difficult to see.

There are many nice touches scattered throughout the publication that increases its value as a reference. Many smaller diagnostic guides, host lists, and other topics are presented in highlighted boxes located in relevant sections. Some examples include "Key to Insect Groups Causing Injury to Foliage," "Deformities Caused by Eriophyid Mites in Colorado," and "General Timing of Scale Crawler Appearance for Common Colorado Scale Insects." The authors have included two sections that address other insects associated with trees and shrubs. The first are miscellaneous insects that are encountered from time to time. The second describes the more common beneficial insects that aid in biological control of insect pests, including a brief mention of insect diseases.

Comments to this point have been directed at the insect component of this publication. This reference also addresses disease and abiotic disorders of woody plants. This combination broadens the utility of the work and puts in the hands of the user a single reference for diagnosing problems when the causal agent is unknown. As an entomologist, my knowledge of symptoms for disease and abiotic disorders of woody plants may not be as good as it should. This reference helps to bridge those weaknesses and allows for a quicker diagnosis without necessitating the need for searching another reference.

The book has a soft cover and glue binding. One suggestion for people who will be using this reference frequently, you may want to hole punch and place it in a ring binder. Books of this size and type of binding start to separate quickly under regular use. I suspect this book will be used frequently, too.

In conclusion, this publication presents very useful information on insect and disease problems. As a desk reference, it will prove itself useful as a comprehensive tool used by professionals who are charged with diagnosing disorders of woody plants.

Phillip Glogoza
Department of Entomology
North Dakota State University
Fargo, ND 58105
American Entomologist
Vol. 48, No.1, Spring 2002