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The ecology of insect overwintering
BOOK
REVIEWS
Insect physiology The Hot-Blooded
Insects
by B. Heinrich Springer-Verlag, 1993. DM198.00 hbk (601 pages) ISBN 3 540 56302 4
The Ecology of Insect Overwintering by S.R. Leather, K.F.A. Walters and J.S. Bale Cambridge University Press, 1993. f40.00/$59.95 hbk (x + 255 pages) ISBN 0 52141758 9
A
11those who have read and enthused over Bumblebee Economics’ as one of the few truly rewarding syntheses of disciplined academic ecophysiology and genuinely insightful natural history will have awaited Bernd Heinrich’s latest offering with eager anticipation. Where the earlier book took us into the world of a single genus, balancing the bumblebee budget in the face of an ever-changing, environmental energy supply, the new work takes a much broader look at the temperature biology of insects, showing us the advantages, and also the problems, of a high-energy approach to life. From one man’s persistent and elegant probing of the temperature biology of bees, we have been led to a deeper understanding of the whole biology of many insect taxa, and of their interactions with ecological and environmental stresses; all who work at the interfaces of physiology, ecology and behaviour have cause to be grateful, and all should certainly read this book. The sheer volume of literature cited is one of the works greatest strengths, taking the reader into the biology of most of the major insect groups and introducing their thermal problems, especially in relation to varying body size and locomotory modes. Heinrich’s own work rightly forms the basis for many of the chapters, underlining his enormous influence in the field. Where he disagrees with the theories propounded by others (for example, about reflectance basking in butterflies, their temperatures in voluntary flight, or about non-shivering thermogenesis in bees), he generally presents the controversies fairly enough, and provides pointers into the literature to allow us to judge for ourselves. That said, we might nevertheless find that The Hot-Blooded Insects leaves us a little dissatisfied on two counts. First, as a careful dissection of the evolution of heterothermy and mechanisms of thermoregulation, the book is excellent, but by virtue of its taxonomic organisation, some of the more interesting messages are underplayed, and 114
the interactions of physiological mechanisms with ecological problems become somewhat blurred despite the author’s claim to be taking an ecological perspective. This is fertile ground for modern comparative and phylogenetic biology, but in practice, many of the comparative aspects are lost as we read about dragonflies, moths, cicadas and bees in separate chapters. At the very least, a much more extensive index would have helped a reader dipping in for comparative information; but, even more to the point, one or more review chapters would have added enormously to the book’s usefulness, especially to students. Instead, we are offered only a brief summary, which includes a most discouraging section on what kinds of research are no longer needed and a decidedly narrow prescription of the remaining questions worth pursuing. A second source of mild irritation arises from the laudable intention to write a book accessible to an interested layman, which perhaps inevitably leaves the style falling between two stools -a little too much explanation of simple ideas for an impatient academic audience, but surely also some rather detailed and esoteric physiology for many amateur readers. No doubt both groups will read the book and benefit from it, but a de cision to separate out either the very simple or the very complex, perhaps into self-contained boxes, would have helped both ends of the reading spectrum. The same criticisms could not be levelled at the study of insect overwintering presented by Leather, Walters and Bale, which again represents an attempt to synthesize ecological and physiological understanding, but very much directed at an academic audience. Here we have a classic case of a book introducing a very under-studied phenomenon, which is guaranteed to stimulate further interest: these authors have no need of a summary chapter telling us which problems have been solved and are of no further interest or pointing us to the outstanding questions. The gaps in knowledge are evident on almost every page, with much of the ecological literature dating back to the 1950s and 1960s and regrettably concentrated on lepidopterans, beetles and aphids. Ecologically based chapters on the characteristics of overwintering environments are dwarfed by those on the control of diapause and the physiology of cold-hardiness. Nevertheless, on the basis of these chapters, the authors are able to assemble a particularly valuable section (chapter 5) on the costs and benefits of overwintering, where physiological issues can be set in context with the ecology and evolution of overwintering life histories. The comparative analysis of patterns in different taxa is treated somewhat simplistically, with little beyond taxonomic listings, again revealing some fertile openings for good research, and there is sur-
prisingly little on overwintering freshwater stages. However, this chapter provides sufficient insight into the ecophysiology of overwintering species to lead on to a useful discussion of potential pest control measures applied in winter and prospects for forecasting from winter sampling to spring outbreaks for a range of economically important species in Europe and North America, thus ensuring a market in most agricultural and forestry institutions. This book is certainly not as elegantly written as Heinrich’s, and the inevitable gaps and uncertainties make it a much less satisfying read. In the long run, though, it may well be of more real value to a broad range of entomologists and ecologists, not least because it has an excellent bibliography and a really useful index to ensure that it will be consulted repeatedly for specific information. Rather more of us will be able to afford it too: sadly the greatest drawback to disseminating Heinrich’s thoughts to amateurs and professionals alike will be their dreadfully inflated pricetag! Pat Wlllmer School of Biological and Medical Sciences, St Andrews University, Fife, UK KY15 5LH
References 1 Heinrich, B. (1979)Bumblebee Economics, Harvard University Press
Wetlands in retreat Wetlands of the World: Inventory, Ecology and Management, Vol. 1. Africa, Australia, Canada and Greenland, Mediterranean, Mexico, Papua New Guinea, South Asia, Tropical South America, United States edited by D.F. Whigham, D. Dykyjovd and S. Hejny Kluwer Academic Publishers, 1993. f162.00/$286.00 hbk (xx + 768 pages) ISBN 0 7923 1685 1
M
an has rearranged, filled in, drained, poisoned and otherwise wrecked wetlands in a relentless search for farmland, disease-free neighborhoods, floodless homes, a free (or at least cheap) meal and economic expansion that is quickly leading to world homogenization. The losses have accumulated so rapidly and completely that there are exceedingly few wetlands in a natural condition. The modern ‘discovery’ of wetland values and functions, a continuing societal grasping for more, more, more, and a TREE uol. 9, no. 3 March
19.94
REVIEWS
Insect physiology The Hot-Blooded
Insects
by B. Heinrich Springer-Verlag, 1993. DM198.00 hbk (601 pages) ISBN 3 540 56302 4
The Ecology of Insect Overwintering by S.R. Leather, K.F.A. Walters and J.S. Bale Cambridge University Press, 1993. f40.00/$59.95 hbk (x + 255 pages) ISBN 0 52141758 9
A
11those who have read and enthused over Bumblebee Economics’ as one of the few truly rewarding syntheses of disciplined academic ecophysiology and genuinely insightful natural history will have awaited Bernd Heinrich’s latest offering with eager anticipation. Where the earlier book took us into the world of a single genus, balancing the bumblebee budget in the face of an ever-changing, environmental energy supply, the new work takes a much broader look at the temperature biology of insects, showing us the advantages, and also the problems, of a high-energy approach to life. From one man’s persistent and elegant probing of the temperature biology of bees, we have been led to a deeper understanding of the whole biology of many insect taxa, and of their interactions with ecological and environmental stresses; all who work at the interfaces of physiology, ecology and behaviour have cause to be grateful, and all should certainly read this book. The sheer volume of literature cited is one of the works greatest strengths, taking the reader into the biology of most of the major insect groups and introducing their thermal problems, especially in relation to varying body size and locomotory modes. Heinrich’s own work rightly forms the basis for many of the chapters, underlining his enormous influence in the field. Where he disagrees with the theories propounded by others (for example, about reflectance basking in butterflies, their temperatures in voluntary flight, or about non-shivering thermogenesis in bees), he generally presents the controversies fairly enough, and provides pointers into the literature to allow us to judge for ourselves. That said, we might nevertheless find that The Hot-Blooded Insects leaves us a little dissatisfied on two counts. First, as a careful dissection of the evolution of heterothermy and mechanisms of thermoregulation, the book is excellent, but by virtue of its taxonomic organisation, some of the more interesting messages are underplayed, and 114
the interactions of physiological mechanisms with ecological problems become somewhat blurred despite the author’s claim to be taking an ecological perspective. This is fertile ground for modern comparative and phylogenetic biology, but in practice, many of the comparative aspects are lost as we read about dragonflies, moths, cicadas and bees in separate chapters. At the very least, a much more extensive index would have helped a reader dipping in for comparative information; but, even more to the point, one or more review chapters would have added enormously to the book’s usefulness, especially to students. Instead, we are offered only a brief summary, which includes a most discouraging section on what kinds of research are no longer needed and a decidedly narrow prescription of the remaining questions worth pursuing. A second source of mild irritation arises from the laudable intention to write a book accessible to an interested layman, which perhaps inevitably leaves the style falling between two stools -a little too much explanation of simple ideas for an impatient academic audience, but surely also some rather detailed and esoteric physiology for many amateur readers. No doubt both groups will read the book and benefit from it, but a de cision to separate out either the very simple or the very complex, perhaps into self-contained boxes, would have helped both ends of the reading spectrum. The same criticisms could not be levelled at the study of insect overwintering presented by Leather, Walters and Bale, which again represents an attempt to synthesize ecological and physiological understanding, but very much directed at an academic audience. Here we have a classic case of a book introducing a very under-studied phenomenon, which is guaranteed to stimulate further interest: these authors have no need of a summary chapter telling us which problems have been solved and are of no further interest or pointing us to the outstanding questions. The gaps in knowledge are evident on almost every page, with much of the ecological literature dating back to the 1950s and 1960s and regrettably concentrated on lepidopterans, beetles and aphids. Ecologically based chapters on the characteristics of overwintering environments are dwarfed by those on the control of diapause and the physiology of cold-hardiness. Nevertheless, on the basis of these chapters, the authors are able to assemble a particularly valuable section (chapter 5) on the costs and benefits of overwintering, where physiological issues can be set in context with the ecology and evolution of overwintering life histories. The comparative analysis of patterns in different taxa is treated somewhat simplistically, with little beyond taxonomic listings, again revealing some fertile openings for good research, and there is sur-
prisingly little on overwintering freshwater stages. However, this chapter provides sufficient insight into the ecophysiology of overwintering species to lead on to a useful discussion of potential pest control measures applied in winter and prospects for forecasting from winter sampling to spring outbreaks for a range of economically important species in Europe and North America, thus ensuring a market in most agricultural and forestry institutions. This book is certainly not as elegantly written as Heinrich’s, and the inevitable gaps and uncertainties make it a much less satisfying read. In the long run, though, it may well be of more real value to a broad range of entomologists and ecologists, not least because it has an excellent bibliography and a really useful index to ensure that it will be consulted repeatedly for specific information. Rather more of us will be able to afford it too: sadly the greatest drawback to disseminating Heinrich’s thoughts to amateurs and professionals alike will be their dreadfully inflated pricetag! Pat Wlllmer School of Biological and Medical Sciences, St Andrews University, Fife, UK KY15 5LH
References 1 Heinrich, B. (1979)Bumblebee Economics, Harvard University Press
Wetlands in retreat Wetlands of the World: Inventory, Ecology and Management, Vol. 1. Africa, Australia, Canada and Greenland, Mediterranean, Mexico, Papua New Guinea, South Asia, Tropical South America, United States edited by D.F. Whigham, D. Dykyjovd and S. Hejny Kluwer Academic Publishers, 1993. f162.00/$286.00 hbk (xx + 768 pages) ISBN 0 7923 1685 1
M
an has rearranged, filled in, drained, poisoned and otherwise wrecked wetlands in a relentless search for farmland, disease-free neighborhoods, floodless homes, a free (or at least cheap) meal and economic expansion that is quickly leading to world homogenization. The losses have accumulated so rapidly and completely that there are exceedingly few wetlands in a natural condition. The modern ‘discovery’ of wetland values and functions, a continuing societal grasping for more, more, more, and a TREE uol. 9, no. 3 March
19.94