parasitoids: behavioral and evolutionary ecologyby h.c.j. godfray

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Parasitoids: Behavioral and Evolutionary Ecology by H.C.J. Godfray Review by: Ian C.W. Hardy and Jacques J.M. Van Alphen Journal of Animal Ecology, Vol. 63, No. 4 (Oct., 1994), pp. 1009-1010 Published by: British Ecological Society Stable URL: http://www.jstor.org/stable/5282 . Accessed: 03/05/2014 02:33 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp . JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. . British Ecological Society is collaborating with JSTOR to digitize, preserve and extend access to Journal of Animal Ecology. http://www.jstor.org This content downloaded from 194.29.185.101 on Sat, 3 May 2014 02:33:51 AM All use subject to JSTOR Terms and Conditions

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Parasitoids: Behavioral and Evolutionary Ecology by H.C.J. GodfrayReview by: Ian C.W. Hardy and Jacques J.M. Van AlphenJournal of Animal Ecology, Vol. 63, No. 4 (Oct., 1994), pp. 1009-1010Published by: British Ecological SocietyStable URL: http://www.jstor.org/stable/5282 .

Accessed: 03/05/2014 02:33

Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at .http://www.jstor.org/page/info/about/policies/terms.jsp

.JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range ofcontent in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new formsof scholarship. For more information about JSTOR, please contact [email protected].

.

British Ecological Society is collaborating with JSTOR to digitize, preserve and extend access to Journal ofAnimal Ecology.

http://www.jstor.org

This content downloaded from 194.29.185.101 on Sat, 3 May 2014 02:33:51 AMAll use subject to JSTOR Terms and Conditions

1009 Book Reviews

keep in touch with current developments over a wide range of disciplines in population and evolutionary biology. Given its important position, it is interesting to observe the way in which particular themes surface in the selection of reviews each year.

Volume 24 has a distinctly phylogenetic flavour, with at least eight of the 21 chapters dealing directly with issues of historical reconstruction. C. Patterson, D.M. Williams & C.J. Humphries, despite their efforts to be positive, paint a rather gloomy picture for the prospects of reconciling morphological and molecular phylogenies. This is not because the phylogenetic hypotheses are in conflict but because neither method is yet able to give the desired resolution to anything more than the simplest phylogenetic problem. The chapter provides a valuable dose of realism amidst the euphoria about molecular systematics.

Undaunted by these problems, F.H. Sheldon & A.H. Bledsoe review progress in avian molecular sys- tematics and R.L. Honeycutt & R.M. Adkins deal with data on eutherian mammals. Phylogenetic recon- struction is a key element in the fascinating story of the house mouse, presented by P. Boursot and others.

Using phylogenies to underpin comparative analy- ses is another growth area that is well covered. A review of methods, by D.B. Miles & A.E. Dunham, will be a very valuable entry point to the literature for many workers. This chapter, and also a discussion of miniaturization of body size by J. Hanken & D.B. Wake, raise the issue of 'phylogenetic constraint' which is considered at length in a review by M.C. McKitrick. Personally, I remain unconvinced that the concept of a constraint offers anything over and above the limitation of evolutionary progress by the supply of mutations, by conflicting selection pressures on individual characters, or by selection on genetically correlated characters. However, progress towards explicit, phylogenetically based definitions of con- straints must help to resolve the debate about their explanatory power.

The opening chapter of this year's volume deals with another rather misunderstood concept: the idea of chaos. Posing the appealing question, 'Is mother nature a strange attractor?' (but declining to answer it!), A. Hastings and others provide a guide to the issues of chaos in ecology. While not to be read too late at night, this contribution will help the un- initiated to appreciate the importance of chaos as well as giving food for thought to many already in the field.

The remaining chapters in this volume maintain the high standard and cover a diverse range of issues from 'Sibling species in the sea' (N. Knowlton) to 'The phenology of tropical forests' (C.P. van Schaik et al.). With volumes like this, Annual Reviews will undoubt- edly continue to be at the forefront of the secondary literature.

R. K. BUTLIN

H.C.J. Godfray (1994) Parasitoids: Behavioral and Evolutionary Ecology. Pp. 520. Monographs in Behavior and Ecology, Princeton University Press, Princeton, USA. Clothback: ?50.00/US$65.00 ISBN 0-691-03325-0. Paperback: ?23.50/US$29.95 ISBN 0-691-00047-6.

There is much in this book: Godfray has produced a major review. Parasitoids are important organisms; they are incredibly common, they can be deployed as powerful tools in biological control programmes and, as is the focus of this book, they are among the most ideal of study animals for the evolutionary ecologist. Their many variations on a relatively simple life-cycle, the unusually direct link between observable behav- iour and measurable reproductive success and numer- ous other attributes, such as the possession by many of a mechanism facilitating sex ratio control, have combined to make parasitoids influential in the testing and development of evolutionary and ecological the- ories. The literature on parasitoid biology is conse- quently vast and, although concisely written, in cover- ing it this book is long.

The book begins by guiding the reader through the research rationale of the evolutionary ecologist, defining terms used throughout the book, introducing parasitoid taxonomy and outlining general parasitoid natural history (paying special attention to some unusual life-cycle variations). Although the book covers all animals with a parasitoid life-cycle, there is relatively little discussion of non-hymenopteran para- sitoids. This simply reflects the fact that the vast majority of parasitoids are Hymenoptera and most research effort has been directed towards these. The following three chapters (2-4) competently address the sequence of problems faced by the adult female parasitoid in search of reproductive success: how to find hosts, whether to accept an encountered host and, if so, how many eggs to lay and with what sex ratio. After a short, though fascinating, chapter covering very recent research on elements which distort normal sexual reproduction, the text turns to problems faced by the immature parasitoid: surviving host defences, competition from other parasitoid larvae. The pen- ultimate chapter returns to the adult parasitoid. God- fray discusses a cornucopia of important ingredients in the parasitoids life: the relationship between size and fitness (linked to host acceptance and clutch size), the variation in mating systems and dispersal abilities (linked to sex ratio), overcoming hosts defences against parasitoid attack and defending resources against other parasitoids and, finally, diapause, host synchronization and their consequences for popu- lation dynamics. The final chapter reviews theory and evidence for factors influencing the evolution of para- sitoid life-histories and patterns in parasitoid com- munities.

Although Godfray presents a synthesis of what is

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1010

Book Reviews known, placed in a clear theoretical framework, the book is more than just a literature review. The text is peppered with informed opinion (mostly Godfray's own, but also that of other experts, apparently extracted by interrogation [p. 356]!) and highlights many promising areas for future research. Nonethe- less, these very much reflect the state of the art and some areas receive very little attention. Life-histories, for example, are discussed in relation to community ecology, because most of the published literature on parasitoid life-histories is concerned with community structure. There is no doubt that other parasitoid spec- ies in the community exert an important selective pres- sure on the evolution of a parasitoid's life-history, but this is by no means the only viewpoint from which parasitoid life-history can be studied. One approach might be to explore how life-history differences are related to differences in foraging behaviour using dynamic optimization models. This promising area of research has not yet received much attention and is thus not discussed in the book, although stochastic dynamic modelling (of foraging decisions) is discussed in Chapter 3.

The chapter dealing with parasitoid sex ratio evol- ution is one of the best reviews of the subject so far, and will provide the 'novice' reader with the synthesis which Kjellberg (1994) found so lacking in a recent collection of sex ratio reviews (Wrench & Ebbert 1993). For example, the description of the differences (and the equivalence) of the 'individual and kin selec- tion' and the 'hierarchical selection' approaches to interpreting the female biased sex ratios predicted by local mate competition theory is the most lucid yet, and should help many through this difficult area. Although sex ratio theory is covered quite thoroughly, we would have liked to have seen a more detailed discussion of some of the important and interesting modifications to local mate competition theory which have kept theoreticians busy for the better part of 30 years. The summary of their modelling efforts in Table 4.1 is succinct, but some more text and figures would have been a welcome addition to an otherwise excel- lent chapter.

The value of Godfray's book extends beyond the conventional boundaries of behavioural and evol- utionary ecology. Much work on parasitoids has been carried out by applied entomologists, and it is to these that parasitoid evolutionary ecologists owe a great deal of their background knowledge. For instance, many studies of parasitoid foraging behaviour have been carried out in relation to biological control of insect pests. Until the late 1970s these mostly studied foraging from a proximate, causal or mechanistic stand-point, with a strong emphasis on which stimuli parasitoid use to find their hosts and assess host qual- ity. More recently, natural selection thinking has pro-

ved to be a powerful instrument in the analysis of the function of parasitoid behaviour and has inspired the development of much theory. Yet, this theoretical work and its empirical tests have often been ignored in recent applied studies; possibly because the math- ematical jargon of theoretical papers scares off many an applied entomologist? Godfray's book, which reviews both causal and functional approaches and explains theory without presenting the mathematics, could provide a significant link between ecological theory and its application in pest control.

Finally, although this is a praiseworthy and admir- able book, a few minor niggles remain. The subject matter is generally disseminated with clarity, making the text pleasantly readable but there are times when the structure of the text degenerates into a blizzard of examples, which inform but daze the reader. In covering so many species, often from groups with poorly resolved taxonomies, nomenclatural errors are hard to avoid. A Ganapsis species referred to in the literature as Pseudoeucolia mellipes has been 'rena- med' by Godfray as Leptopilina mellipes. The error occurred because Nordlander's (1980) revision showed that the correct name for Pseudoeucolia bochei is Leptopilina heterotoma. Incidentally, it is the latter species which is shown on page 8 of the book and not L. clavipes as indicated by the figure caption. There are also some confusing typographical errors. For example, in the chapter on sex ratios, there are a number of instances where 'males' and 'females' are mixed up. Also in this chapter, we found the frequent use of 'more male biased' to describe sex ratios which are actually female biased rather unfortunate. God- fray's terminology is not incorrect but, since it may seem to imply a male biased sex ratio, we would have preferred 'less female biased'.

In summary, this is an excellent book which will be of great use and interest to newcomers to the field and old hands alike: to have read it is to know many things. If you are interested in evolutionary ecology and/or parasitoid biology, we recommend you to read this book and then keep it within arm's reach. You will find yourself frequently plucking it from the book- shelf.

IAN C.W. HARDY &

JACQUES J.M. VAN ALPHEN

References

Kjellberg F. (1994) Book review. Journal of Evolutionary Biology, 7, 115-124.

Nordlander G. (1980) Revision of the Genus Leptopilina Foster, 1869, with notes on the status of some other genera (Hymenoptera: Cynipodae: Eucoilidae). Entomologica Scandinavica, 11, 428-453.

Wrench, D.L. & Ebbert, M.A. (1993) Evolution and Diversity of Sex Ratio in Insects and Mites. Chapman and Hall.

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