BOOK REVIEW

R. Harrington and N. E. Stork (eds.): 1995, Insects in a Changing Environment, Academic Press, London, 535 pp., $60

This book was prompted by the 1992 UN Conference on Environment and Devel- opment held in Rio de Janeiro, which highlighted concerns about environmen- tal threats such as climate change, pollution, and land-use changes. Such global changes impact all life on earth, including insects. Insects dominate animal life, make up about 90% of all species on Earth, and play a major role in all ecosys- tems. They destroy about 15% of potential food crops per year despite all efforts to control them. Insects vector some of the most deadly human diseases, including malaria and dengue. However, insects are essential for a healthy and productive environment because of their vital roles as pollinators; biocontrol agents of pests; food for birds, fishes, and mammals; and decomposers for recycling organic wastes.

Because of the dominant role of insects in the ecology of nature, the impacts of environmental changes on insects deserve attention. Thus, for the 17th Symposium of the Royal Entomological Society, a forum was set up to examine various aspects of environmental changes on insects. The volume that summarizes the proceedings of the symposium is divided into five parts: (I) Introduction and magnitude of the task; (II) Effects of climate change; (III) Impacts of gases and pollutants; (IV) Land-use changes; and (V) Miscellaneous papers. These major parts indicate the enormous task that faced the entomologists in assessing the complex interactions affected by environmental changes.

The complexity of the impacts of climate change is illustrated in the book with the dynamics of phytophagous insects associated with their host plants. These insects are affected directly by change in temperature, rainfall, and light, and indi- rectly by changes that take place in the plants themselves. Insects are poikilotherms and, therefore, in general, insect populations will thrive with global wanning. At the same time, they are affected by changes in humidity, evapotranspiration, and rain- fall intensity which may improve the environment for some insects while making it unfavorable for other insect species.

Equally important, as many authors point out, some of these changes have indirect impacts on insects via their host plant by changing the rate of plant growth, nutritional makeup, and the various other chemicals that exist in plants. Hence, to understand and possibly predict changes in one species of phytophagous insect, entomologists must have knowledge of the impacts of all the factors on individual insects and in combination with all other factors. This confirms the complexity

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of the task and further confirms the statement made by the famous entomologist Professor B. P. Uvarov in his book Insects and Climate (1931) who reported that single-factor experiments are unlikely to be very helpful in interpreting the ecology of insects in nature.

As contributor J. H. Lawton reported, no insect type has the sole use of a host plant. It shares the plant with other species of phytophagous insects, as well as with some mammalian herbivores and parasitic plant-pathogens. In addition, the phytophagous insect has a complex of natural enemies attacking it, plus various interacting competitors.

Although entomologists use CO2 to anesthetize insects in experiments, the CO2 level in the atmosphere probably will not be sufficiently high to directly affect any insects. However, changes in CO2 levels in the atmosphere will influence the growth and physiology of the plants on which insects feed. This, in turn, can influence the feeding, growth, and behavior of phytophagous insects. This was illustrated in the volume, which reported on the recent experiments of Lindroth et al. with three species of trees (popular, Populus tremuloides; oak, Quercus ruba; and maple, Acer saccharum) and two species of caterpillars (gypsy moth, Lymantria dispar, and the tent caterpillar, Malacosoma disstria). Small trees were grown for 60 days under ambient (385 ppm) and elevated levels (642 ppm) of CO2. The feeding performance and growth of the caterpillars was then tested for the last ten days. Both caterpillar species increased their feeding rates on the high-CO2 popular, but the growth rates of the caterpillars declined. However, gypsy moth larvae grew better on high- CO2 oak, but showed no response to high-CO2 maple. The tent caterpillar did not grow well on high-CO2 maple but was unaffected by the high-CO2 oak. Some of these responses are predictable from the effects of CO2 on primary and secondary leaf metabolites in plants, but not all the responses are predictable based on our knowledge of carbon-nutrient balance.

Again, as Lawton pointed out, these experiments involved only one component in the laboratory and did not involve all the variables that occur in nature, including temperature and rainfall changes, different soil nutrients, and parasites of the trees themselves and of the caterpillars.

In addition to global CO2 change and warming, numerous pollutants and land- use changes are affecting insect biodiversity and population dynamics. Several chapters in the book report on the impacts of various gaseous pollutants on insect populations. For example, nitrogen dioxide is commonly associated with the bum- ing of fossil fuels, especially in urban areas and motor ways. The increase in nitrogen which is then available to plants has resulted in the increased abundance of aphids and leafhoppers near roadways and industrial plants. Some of the other gaseous pollutants may increase or decrease insect populations depending on the direct and indirect effects on the herbivorous insects.

Although pesticide pollutants were mentioned, it was surprising that no mention was made in the volume of the impact of herbicides on the physiology of crops and other plants, especially since herbicides and other pesticides are widely used

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and their use is increasing rapidly worldwide. Herbicides applied at recommended dosages on crops may affect the physiology of the target crop, increasing insect populations by more than three times. Herbicides also are reported to increase the levels of certain toxins in crops like potassium nitrate and cyanide. High levels of these and other toxins may be lethal to insects as well as to mammalian herbivores. Another aspect of pesticides not dealt with is the resistance problem and the interactions with beneficial natural enemies.

The volume also reports that understanding and predicting human-disease dynamics related to insect vectors is as complex as those of phytophagous insects. Dengue is spread by Aedes mosquitoes and, according to the World Health Orga- nization, is spreading rapidly, especially in urbanized areas of the world. Global wanning is expected to intensify this disease, but how much and in what way is not known.

Similar to dengue, malaria will probably intensify due to global warming but for different reasons. In general, Anopheles mosquitoes do not do well in urban areas because they require streams and swampy areas to breed in and cannot breed in temporary water containers like tires and tin cans. Anopheles also cannot breed in the heavily polluted water which is typical in many urban areas in the tropics.

Another human disease that will probably increase with a warming trend is lyme disease transmitted to deer, deer mice, and humans by the deer tick. The tick does especially well under high temperatures and prefers a sandy, well drained soil. Thus, the tick and the disease organism will become a greater problem in the future with increased global warming.

Overall, the chapters in this volume are well documented and will, therefore, serve as an excellent reference source to entomologists and other scientists inter- ested in the complex interactions of insects and potential environmental change. Despite some deficiencies in coverage and some redundancy of coverage on the interactions of insects and environmental change, this is a valuable book that con- tains a great deal of sound information that will be of interest to entomologists, climatologists, ecologists, environmental scientists, agriculturists, foresters, geog- raphers, and others.

Department of Entomology, Cornell University, Ithaca, NY 14853-0901, U.S.A.

DAVID PIMENTEL

BOOK REVIEW

Stephen H. Schneider, Editor-in-Chief, Encyclopedia of Climate and Weather, 1996, Oxford University Press, New York, 2 Vols., 929 pp.

I must declare my biases before reviewing this major work. I am among those who put 'climate' ahead of 'weather', as does the title. I see the climatic system as a central aspect of the sciences of nature. I am a friend of the Encyclopedia's editor- in-chief, who is also the founding editor of this journal. And I am mysteriously one of the twenty people given biographies in the text. To be set alongside Aristotle, Benjamin Franklin, Thomas Jefferson and Louis Agassiz is daunting enough. But still less do I rank myself with the Bjerknes, father and son, or Rossby, or Chamey, or Lorenz. I 'm not in that league.

By any standards this is a large achievement, without any real parallel in our science. Malone's Compendium of 1951 was a notable predecessor, and there have been several good glossaries. But the present work is truly encyclopedic, and goes well beyond the limitations of its predecessors. It is mostly addressed to an enquiring public, but certain articles are written for the specialist, perhaps rather unevenly. In the sampling process I discovered, for example, that energy, entropy and enthalpy were all there under E, but enstrophy wasn't. Perhaps it is too much of a newcomer in our vocabulary, possibly seen as jargon.

Of course one doesn't 'read' an encyclopedia like a book. One dips, one consults, one forages, one goes on a trip to Serendip. One identifies strengths, one tut-tuts at perceived weaknesses. Overwhelmingly, as I performed these rites, I found strength from a remarkable cast of authors and editors. Most of the articles were written by currently active specialists, who have done a good job of covering a wide waterfront. A few years ago the coverage would have been narrower, because meteorologists and climatologists saw themselves with tunnel vision. Thanks mainly to the rise of climatic studies the field is now more aware of its neighbors.

What did I find to complain about? In the cast of biographees, I'd have thought that Mikhail Budyko, Reggie Sutcliffe and Bert Bolin should have been there. Budyko transformed physical climatology, as to a lesser extent did Howard Penman (who, however, never admitted to being anything but a physicist). Sutcliffe made more of a contribution to cyclone theory and baroclinic instability than the text recognises. And Bolin has for long presided over the world climate and global change programs. I'd have added Tom Malone, the travelling prophet of our field, and Reid Bryson, who put climatic change on the map. Ed Lorenz deserves more

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space than he got. And how about Helmut Landsberg? We could all compile such lists. No one's choice of stars is quite like anyone else's.

In technical matters, the many articles on cyclones and precipitation fail to do justice to the relation between wave velocities and stream trajectories - the conveyor belt phenomenon. Nowhere could I find a comprehensive treatment of the remarkable work done in the mid-Western U.S. and in the U.K. on the detailed morphology of rainbelts and severe storms. The mesoscale in general comes off too lightly. Mesoscale convective complexes, MCC's (letters which to a Brit denote the headquarters of cricket) are a striking reality in many hot, humid areas, but fail to make the subject index (though one can find them as 'systems'). The superb role of satellite and radar technology in unravelling these sub-grid processes is understated. So is the work of Browning and Fujita, and the people they have trained and inspired.

But the importance of this overview is that it is there, like Mount Everest, the Mississippi and Yankee Stadium. It will be a solid, permanent feature of our landscape and environment, to be updated from time to time (probably in its electronic form). The New York house of Oxford University Press is to be congratulated on offering such impressive competition to their rival, Cambridge University Press, which has had a near-monopoly on IPCC reports. The chief value of this work will be to make our science accessible to the rapidly growing body of other scientists, journalists and politicians who have at last recognized the centrality of climate in world affairs. Stephen Schneider has had the energy, ability and ambition to meet this crying need.

301 Lakeshore Road W. F. KENNETH HARE, C.C., F.R.S.C. Oakville, Ontario L6K 1G2 Canada

Editor's Note: It is always an uneasy task for a joumal editor to ask a reviewer to provide an honest appraisal of a book written or edited by that editor. That is why I turned to F. Kenneth Hare, whose forthright advice on interdisciplinary quality criteria helped to launch this joumal on its interdisciplinary path in the 1970s, and whose scientific opinions are not colored by his personal relationship with colleagues. In fact, I could hardly imagine another in our profession with the breadth and candor to perform such a service. I am therefore indebted to Ken Hare for undertaking this review and also, true to form, for pointing out a number of significant improvements needed in the Encyclopedia that I promise to undertake should Oxford University Press provide the opportunity for a second edition. I also welcome similar comments from other readers of this journal and The Encyclopedia o f Climate and Weather, for such critical commentary is what keeps our refereed literature, whether an encyclopedia or an interdisciplinary journal, refreshed and improving.