Roger Dennis’s “Butterfly Biology Systems” is a comprehensive and highly authoritative work on butterfly ecology. Rather than presenting butterfly biology as a collection of isolated facts, Dennis argues that every aspect of a butterfly’s life – from egg-laying through larval development and mating behaviour to thermoregulation, feeding, and habitat use – should be understood as part of an interconnected biological system. The aim of this book is to explore this complexity, to identify patterns in the life cycles and behavioural characteristics of various butterfly species, and to uncover the connections between them. This book is a dense, ambitious synthesis by someone who has spent decades in the discipline.
The book is divided into four sections.
Section A introduces the fundamentals (language and concepts) of systems theory, discussing concepts such as system states, relationships, feedbacks, measurement, phylogenetic context, and evidence synthesis.
Section B provides insights into the biology of butterflies and places it within a broader evolutionary and ecological context. The chapters address taxonomic constraints, temporal and spatial scales, habitat, morphological diversity, trade-offs, and the integration of biological databases.
Section C deals with the life cycle of butterflies, whilst Section D focuses on the behaviour of butterflies. These two sections are the core of the book, and topics range from reproductive allocation, larval development, diapause, and dispersal to adult feeding, mate location, courtship, oviposition, anti-predator behaviour, and pupation. A distinctive feature of the book is its numerous (more than 100) scientific illustrations, which greatly aid the reader’s understanding of the complex subject matter. What makes this book special is that it does not merely present facts; it also places particular emphasis on showing how these facts are connected and functionally related.
The book is of outstanding academic quality and features a very comprehensive bibliography (120 pages, one-quarter of the entire book) that was up-to-date at the time of publication. The individual concepts are explained in detail and from various perspectives, and many chapters conclude with a summary or a personal note. The numerous figures (many available online as supplementary material and accessible via a QR code provided on page XV of the book), with diagrams, models, and detailed legends, contribute to the academic quality. Overall, the book covers all the key aspects of butterfly ecology and discusses them in great detail, whilst also highlighting, in some places, areas where further scientific research is needed.
Cover of “Butterfly Biology Systems: Connections and Interactions in Life History and Behaviour” by Roger L. H. Dennis (CABI, 2020). Reproduced with permission of the publisher.
The book is not an easy read, and some of the scientific topics are very challenging. However, the high level of detail and coverage of the topics make it an indispensable textbook for graduate students, researchers in insect ecology and evolution, and serious amateur entomologists. It is definitely not a beginner’s introduction to butterflies, but a comprehensive glossary helps readers who are unfamiliar with the systems approach to familiarise themselves with the subject.
In addition to the personal notes mentioned as concluding elements, admiration should also be expressed for Roger Dennis’s work over the last decades, during which he wrote many fascinating and relevant pieces. He did so despite the fact that his health did not always treat him well. His love, devotion, and perhaps even surrender to the biology and ecology of butterflies will remain as a grand heritage for humankind.