Pathogens, Vectors, and Plant Diseases: Approaches to Control is a collection of papers that discusses how vector host interactions, vector ecology, and disease epidemiology can be applied to disease prevention and control. The book deals with innovative strategies pertaining to control of vector-borne viruses and viral infections in plants. One paper discusses nonpesticidal control of vector-borne viruses including soil solarization that uses solar energy for crop protection, and insect sterilization through radiation, chemosterilants or genetic modifications. Another paper discusses chemicals that interfere with nucleic acid and protein synthesis; as these interactions pose no hazards to animal (mammals), the chemicals are suitable for controlling viral diseases. One author examines the use of oil sprays and reflective surfaces as a means of controlling plant viruses transmitted by insects. In the United States, the entry of vector-borne plant pathogens is controlled by plant quarantine. One author lists several ways in effective quarantine procedures, as well as, the safe importation of potential vectors as cultures. This book is suitable for environmentalists, biologists, conservationists, agriculturists, botanists, and researchers in botany and plant genealogy.

Stressing the key role vectors play spread of virus diseases, this volume represents the priorities in practical plant virus research and ways in which their control or management should be sought through an understanding of the practical and environmental aspects of the interactions of viruses with their vectors and their environment. It provides

Vectors of Plant Pathogens is a collection of papers that discusses the interrelationship of plant pathogens with their vectors. This collection deals with the numerous vector groups associated with plant pathogens. One paper describes the biology, feeding behavior and distribution of aphids, leafhoppers, plant hoppers, mealy bugs, whiteflies, psyllids, membracids. Another paper addresses the virus transmission characteristics of the mealy bugs during preliminary fasting or feeding, acquisition access time, post-acquisition fasting or feeding, and the inoculation access time. Other papers also discuss the involvement of insects in transmitting bacterial and fungal pathogens; the authors list unresolved issues such as the role of insects in overwintering of bacterial pathogens or the association of the fungus with a particular vector. One author describes some suspected fungi transmission such as the pea stem necrosis virus, red clover necrotic mosaic virus, and the tomato bushy stunt virus. Another paper examines the fate of plant viruses in mite vectors and convectors particularly the viruses found in wheat, barley, or brome grass. Agriculturists, botanists, and researchers in the field of botany, conservation, and plant genealogy will find this book useful.

Although nematodes had long been suspected as vectors of soil borne plant diseases, unequivocal proof of their implication was not forthcoming until 1958 when Professor William Hewitt and his colleagues in California demonstrated experimentally that Xiphinema ~ was the vector of grapevine fanleaf virus. This opened up a new and exciting field in plant pathology and discoveries quickly followed of other nematode species associated with soil-borne diseases of many different crops and in several countries. After the initial enthusiasm of discovering new vectors and new viruses there followed a period of consolidation in which research workers sought answers to tantalising questions about the location of the virus within the nematode, the factors governing the close speci ficity between virus and vector; and more mundane but equally important and compelling questions about life cycles, geographical distribution, host relations, morphology and taxonomy. No other group of nematodes has attracted such a concentrated effort involv ing many different scientific specialisations and yielding so much progress in a relatively short time. The NATO Advanced Study Institute held at Riva dei Tessali, Italy, during 19 May to 2 June, 1974, provided the forum for a critical discussion of all aspects of biology of virus vector nema todes.

The history of pathogens and vectors, unique symptoms of diseases and economic importance of important viral diseases have been dealt with in the introductory chapter of this book. While highlighting the role of arthropods, nematodes, and fungi; other agents of the spread of plant pathogens have also been included. Important aspects of insect vectors with direct bearing on transmission, i.e. vector identification, biology, feeding apparatus, and mechanism of spread including control of pathogens through vectors are covered comprehensively. As aphids and other hemipterous insects are major insect vectors, the book stresses on this order. There is a focus on the transmission of determinants under different categories of the transmission mechanism. The transmission determinant paradigm comprising coat protein and helper component has been expounded with recent cases. A brief description of new diseases at least one from each genus of plant viruses has been included in this compendium to elucidate the interaction of vector and virus. Phytoplasmal etiology of pathogens has been detailed separately on account of their importance. The transmission of plant viruses through insects with biting and chewing type of mouth parts has been discussed in detail as separate chapter. The latest research in the field of mites, nematodes, and fungi as vectors of plant viruses has been included. How the phytotoxemia is different from other crop disorders, has been critically explained with support from suitable and common examples of crop disorders. The book also highlights the effects of plant viruses on their vectors. An account of classification of plant viruses has also been given for better understanding of subject matter. Likewise, the information on the electron microscope along with its use has been included so as to define the procedure of examining sub-microscopic entities. The latest developments in the management of plant pathogens through vector management have been discussed with special reference to the use of biotechnology, crop protection, and plant resistance. The book will be of value to the teachers and to researchers. It will also be useful for extension workers in managing crop disorders. Students and researchers of entomology, plant pathology, plant protection and virology disciplines will obtain the latest in the field, through this book.