CROP PROTECTION Vol. 6 December 1987, 410-414

Book reviews

World Crop Pests (Editor-in-Chief W. Helle). Volumes 1A and 1B: Spider Mites: Their Biology, Natural Enemies and Control, ed. by W. Helle and M. W. Sabelis. Volume 1A: ISBN 0-444-42372-9. (xviii+406 pp; US$105.50; Dfl. 285.00). Volume 1B: ISBN 0-444- 42373-7. Amsterdam: Elsevier. 1985. (Available in the USA and Canada from Elsevier Science Publishers Co. Inc., PO Box 1663, Grand Central Station, New York, NY 10163.)

This two-part volume is the fist of a series which will deal with the biology, natural enemies and control of major groups of pest animals. Volume 1A is concerned with the anatomy, phy- logeny and systematics, reproduction and development, physiology and genetics, and ecology of the Tetra- nychidae together with a final section on rearing, sampling, mounting, histo- logical, cytological and toxicological techniques. Volume 1B is concerned, firstly, with the predators and pathogens of the Tetranychidae with particular emphasis on phytoseiid mites, and secondly with damage assessment and the control of Tetra- nychidae in various protected and out- door crops. The latter section also includes chapters on plant breeding, pesticide resistance in Tetranychidae and Phytoseiidae, genetic control, and Tetranychidae as control agents for weeds.

The standard of presentation of volumes 1A and 1B is consistently high with some particularly good line dra- ings and scanning electron micro- graphs, and a clear well-printed text which gives an overall impression of quality; books to be taken care of, and not only because of their price. In addition, for such a complex multi- author text (there are 25 and 35 con- tributors to the 29 and 43 chapters in volumes 1A and 1B respectively), the editors are to be congratulated for the degree of consistency they have achieved between chapters--a task perhaps made easier by their own major contributions to each sub- volume.

Inevitably for a multi-author text,

there are some aspects which are not perhaps ideal: for example, some of the chapters might have benefited from amalgamation without spoiling the format, a case in point being the separate chapters on pesticide resis- tance in Tetranychidae and Phyto- seiidae. With the format adopted, a considerable degree of cross-referenc- ing between chapters is required and I found that this was particularly the case for parthenogenesis, where careful reading of several chapters was necessary (fortunately, both sub- volumes are provided with separate general indices, plus indices to spider mites and predators). I would also have liked to see an overview of chemical/ integrated control, the only summary tables on acaricides and other pesti- cides affecting mites being concerned with resistance. Furthermore, the most promising new group ofacaricides, the avermectins, are barely mentioned and, in one of the few errors, spelt incorrectly.

However, the above criticisms are minor ones and the books succeed admirably in the stated aim 'of pro- viding a synthesis of much of the know- ledge on basic and applied aspects of the biology of spider mites and their natural enemies' with a collection of well-written and stimulating articles. The books provide an excellent back- ground for the instigation of research projects (references are included up to 1983/1984) and it was interesting, for example, to see how little we know about the neurochemistry of spider mites. I would recommend these books to anyone concerned with spider mites at the postgraduate and professional level, despite the high cost of such a text.

DENIS J. WRIGHT

The Science of Allelopathy, ed. by Alan R. Putnam and Chung-Shih Tang. ISBN 0-471-83027-5 (xiv+ 317 pp; £50.40). New York: Wiley- Interscience. 1986.

A first criticism of any work which has a title of The Science o f . . . must be

whether there is sufficient justification for the collection of the body of work under a common heading; it is dis- appointing to find that in this work there are included a wide range of studies which might be better expressed as chapters in different volumes. An example is Chapter 9 by H. G. Cutler, a review of the problems and possibilities of fungal metabolite isolation which does not mention allelopathy at all and yet contains invaluable experience to those inter- ested in fungal metabolite work. Similar comments can be made on the chapter by Duke on microbial products as herbicides.

As one would expect of any multi- authored work, there are very variable chapters, but the editors are to be congratulated on avoiding the pitfalls of repetition of major areas of work. The limited progress on allelopathy may be responsible for the repetition which does occur: for example, juglone, phlorizin and amygdalin appear in the introductions to three chapters. A surprising omission in Chapter 2 on stimulatory effects is the lack of recognition of the work of Schroth and others on plant-growth- stimulating bacteria.

Ferulic acid may characterize some of the problems of this work and of allelopathy. It appears in seven chapters as a product of the degrada- tion of corn, rice, rye and Imperata cylindrica; as a constituent of coffee; as an inhibitor of sorghum (germination), clover (growth), Nitrosomonas and of a wide range of physiological processes. Yet there is no drawing together of these results and conclusions as to specificity or the occurrence of ferulic acid as a general, toxic breakdown product of plant residues.

Allelopathy then, as repeatedly defined, seems to contain a number of areas of study: specific plant-plant interactions, such as the juglone and amygdalin phenomena which can be satisfactorily described as specific bio- chemical interaction; the non-specific toxicity of degradation residues, whether this degradation is within the plant or is microbial, and the produc- tion of specific or non-specific toxins

by fungi, bacteria or actinomycetes which are inhibitory to plant growth. My comment on this complex and difficult area is that the different topics may well be better treated separately rather than that unification should be attempted.

On the whole, the book is well pro- duced with a few minor typographical errors. It contains useful information on the metabolites produced b y plants and micro-organisms. It will not form a general text for students but will represent a useful reference work for those engaged in natural product studies. My conclusions are those of some of the authors. Lovett in Chapter 5 says 'The basic deficiencies in much research concerning allelopathy remain. Too few chemicals are identi- fied; even fewer are quantified. Too many phenomena are described; too few rigorous investigations of the primary effects of allelochemicals are carried out. Serious limitations to the acceptance of allelopathy as an eco- logical factor of significance will remain until these shortcomings are rectified.' What more can be said?

KEITH POWELL

Mushrooms--Pest and Disease Control, by J. T. Fletcher, P. F. White and R. H. Gaze. ISBN 0-946707-08-1 (xx+ 156 pp; £15.00). PO Box 2, Ponteland, Newcastle upon Tyne: Intercept. 1986.

The authors have brought an ideal blend of research, advisory and cultural expertise to bear upon the many serious problems which can affect the most valuable horticultural commodity in the UK. They have produced a succinct compendium of information which is otherwise scattered widely through the learned and grower literature.

The commercial pressures posed by marketing forces have demanded continuous production, so that the mushroom farm is typified by intensive monocropping with all stages of cultivation continuously present. As the cropping system involves the pro- duction of a virtually sterilized substrate, all pathogens and pests which are allowed to invade the crop ,are provided with almost unlimited opportunities for population increase.

Prevention is therefore more effec- tive than cure, so that growers require a sound knowledge of the biology of the potentially damaging organisms.

Book reviews

Should problems arise, recognition of the case is vital in order to adopt the most appropriate control measures. The chosen illustrations provide helpful clues to the identity of the problem because they depict charac- teristics readily seen with the naked eye.

The text includes a valuable 25-page section on good hygiene, which draws attention to the many detailed pre- cautions necessary to ensure the effec- tive use of disinfection procedures.

The discussion of the all-important virus diseases which, although now less devastating than in the early 1960s, still cause serious losses, includes some informative, yet simple and well-illus- trated explanations of the techniques used by virologists to detect the presence of viruses.

The advice on the control of mush- room pests refers to strains resistant to pesticides, although it is apparently left to the grower to judge from his practical experience whether such selection has occurred. It is a pity that some guidance is not given on the availability of testing facilities in the MAFF or elsewhere. Bearing in mind the many factors which encourage pest epidemics, 'experience' is an unreliable guide to resistance and, in fact, it is too often cited as an excuse for other short- comings in the hygiene procedures.

Apart from a few typographical errors there is nothing to detract from this book, although I imagine that some would have appreciated the inclusion of addresses for the manu- facturers quoted in Tables 3.2 and 8.1.

Perhaps the most complimentary comment to make on this excellent volume is to echo the aspirations of its publishers, that it will be invaluable to all concerned with the crop--growers, advisers, entomologists, pathologists, teachers and students of horticulture worldwide.

N. W. HUSSEY

Pest Control in Tropical Onions. ISBN 0-85135-143-3 (v+109 pp; £5.00). College House, Wrights Lane, London W8 5SJ: Tropical Develop- ment and Research Institute. World production of the common onion Allium cepa has been estimated at about 22 million tonnes, over half of which were grown in developing countries. This latest manual in the series on tropical onions is therefore welcomed as a source of information on the weeds, diseases, nematodes, insect

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and mite pests of the crop. There is also a short section on storage of mature onions. The manual, intended for agricultural scientists and extension staff in developing countries, provides very practical information on the most important pests, together with advice on control measures. In controlling weeds, a range of herbicides are listed with an indication of the usual dosage, time of application and range of weeds controlled. Elsewhere in the book, pests are considered separately with brief notes on different cultural and other methods of control.

Reference is made to some specialist application techniques such as the use of a gel-based fluid carrier for incor- porating iprodione when drilling pre- germinated seed to control white rot, but in general the reader will need to seek further advice on how to apply the pesticides. In each section there is a useful bibliography for the reader to obtain more detailed information. Pests, and the pesticides used in their control, are listed in an appendix and there is an index.

The book can undoubtedly be recommended as a useful reference book.

G. A. MATTHEWS

The Economics of Integrated Pest Control in Irrigated Rice: A Case Study from the Philippines, ed. by Hermann Waibel. ISBN 3-540-16687- 4 (Berlin); 0-387-16687-4 (New York). (xiii+196 pp; DM 128.00). Berlin, Heidelberg: Springer-Verlag. 1986.

The book starts with a brief intro- duction to the organizational structures associated with crop protection in the Philippines. Then follows an extensive and detailed presentation of the avail- able experimental data from which pest damage can be estimated. Most of the experiments were not designed with pest loss assessment in mind; this in itself highlights the lack of pest damage studies which are a central part of an economic analysis of this kind. Average losses due to pests ranged from 9% to 34%, but in some trials (0-60%), no significant yield differences were observed between infected plots and those protected by insecticide treat- ments.

The relationships between pest infestations and damage are discussed, and damage coefficients for different pests, based on regression equations, are presented. There is also an over- view of the literature on damage co-

CROP PROTECTION Vol. 6 December 1987