When we observe plants in the outdoors, we are likely to notice the visiting insects. Plants and insects communicate in numerous ways, and chemistry plays a key role in these communications. Natural organic compounds determine whether a plant is consumed by insects or avoided by them, and which insects may pollinate its flowers. I was intrigued by these connections during a field seminar where the task was to search for insects. While I found few insect samples initially, the entomologists in the group collected plenty of exciting beetles, caterpillars, and butterflies. My colleagues clearly knew to look for distinct host plants whose plant chemistry attracted specific insects.

This book is aimed at lay readers who have a basic understanding of chemistry. It addresses non-chemists who work at, or enjoy visiting, botanical gardens and science centers, and non-major undergraduate college students. The book can be a supplementary text for students in plant sciences, ecology, entomology, and horticultural programs. By connecting chemistry with plants and insects, the author intends to capture the interest of readers who would like a deeper understanding of the natural world.

Many people have supported me in the writing of this book. I am most grateful to the readers and commentators who generously contributed their suggestions and their knowledge during the book's preparation. I am especially grateful to Jim Keeffe, Eileen Nottoli, Urs Séquin, Verena Rau, and Eveline Larrucea for their encouragement and for their detailed critical reading of the book chapters. Many thanks to John Hafernik for a wonderful field trip and for checking the insect entries. Any errors that stubbornly resisted detection are entirely the author's responsibility. I am grateful to Sandy Jordan for providing insect samples, to Sushila Kanodia for samples of neem, and to Christa Kraus for helpful information on honey and beeswax. My special thanks go to the staff at the Regional Parks Botanic Garden in Berkeley, CA, and to the staff of the University of California Botanical Garden who alerted me to special plants and their insects.

I am greatly indebted to the team at the Royal Society of Chemistry for their continued support and excellent service.

My special thanks go to my husband Carlo for his support, encouragement, and patience.

And many thanks to Elise, Sienna, and Laila for supplying bug materials.

Margareta Séquin

Caterpillar topiary at San Francisco State University.