The cyst nematodes are a major group of plant pathogens of economic importance in many countries throughout the world. Considerable yield losses have been attributed to cyst nematodes attacking potatoes, sugar beet, soybean and cereals. Because of the protective cyst that is formed, which encloses the eggs, they pose special problems in their control and also in preventing their distribution in soil from infested areas. There has been much research on many aspects of the biology of cyst nematodes and the large number of publications are testimony to their importance as crop pests and of the interest of nematologists in the group. Nevertheless, they continue to pose problems because of the complexity of their phylogeny and taxonomy and there is still much to be investigated on their biology, particularly with those aspects which relate to improving the effectiveness of control. In many respects the biology of the various cyst nematode species is similar, although with variations due todifferent interactions with hosts and geographical location. Thus, research on any one species has general applicability and this is particularly so with regard to evaluation of control measures, or to the methodology of soil sampling for the assessment of populations prior to growing crops.

Zusammenfassung
Based on the Proceedings of a NATO Advanced Study Institute on Cyst Nematodes, held in September 21-October 3, 1985, in Martina Franca, Italy

Inhalt
Taxonomy and Phylogeny of Cyst Nematodes.- Morphology and Identification of Cyst Nematodes.- Ultrastructure and Function of Cyst Nematodes.- Testing Hypotheses of Phylogeny of Heteroderidae.- The Development of Individuals and Populations of Cyst Nematodes on Plants.- Physiology of Hatching.- Histology and Ultrastructural Modification Induced by Cyst Nematodes.- Gnotobiology of Cyst Nematodes - its Potential in Basic Research.- Biochemical Reactions and Interactions.- Concepts of Resistance, Tolerance and Susceptibility in Relation to Cyst Nematodes.- Effects of Nematode Attack on the Growth and Yield of Crop Plants.- Agronomic Aspects of Potato Cyst Nematode Infestation.- Limits to Methods for Management of Potato Cyst Nematodes in Western France.- Integrated Control of the Sugar Beet Cyst Nematode.- Cell Responses to Heterodera schachtii Feeding on Susceptible and Resistant Cultivars of Oil Radish.- Ultrastructural Responses in Sugarbeet to Heterodera schachtii.- The Soybean Cyst Nematode.- Sources of Resistance to the Soybean Cyst Nematode.- Heterodera avenae: Virulence and Resistance.- The Biology of Heterodera avenae in Spain.- Incidence of Heterodera avenae in Spring Barley Fields in Denmark.- An Analysis of the Heterodera trifolii Complex and Other Species in the schachtii Group Attacking Legumes.- Observations on a Population of Cyst Forming Nematodes from Carnation.- The Pea Cyst Nematode.- The Carrot Cyst Nematode.- Hatching of the Carrot Cyst Nematode.- Observations on the Population Dynamics and Control of Heterodera carotae in Western France.- Cyst Nematodes in Equatorial and Hot Tropical Regions.- Economic Importance of Cyst Nematodes in North America.- Occurrence of Cyst Nematodes in Portugal.- Cyst Forming Nematodes in Libya.- Host Status of Cyst Nematodes in Iraq.- Cyst Nematodes in India.- Cyst Nematodes in Mexico, Central and South America.- Measuring Field Populations of Cyst Nematodes.- Chemical and Integrated Control of Cyst Nematodes.- An Assessment of the Role of Parasites and Predators in the Regulation of Cyst Nematode Populations.- Quarantine and Legislation.- Participants.