Part I: Virus localization in plants and vectors: 1. Tomato yellow leaf curl virus, a disease sexually transmitted by whiteflies; 2. Possible etiology of eryophyd mite-borne pathogens associated with double membrane-bound particles; 3. An anatomical perspective of tospovirus transmission. Part II: Elucidation of transmission mechanisms: 4. Analysis of circulative transmission by electrical penetration graphs; 5. Analysis of noncirculative transmission by electrical penetration graphs; 6. Ingestion-egestion theory of cuticula-borne virus transmission; 7. Mechanism of virus transmission by leaf-feeding beetles. Part III: Molecular aspects of virus-vector interactions: 8. Caulimoviruses; 9. Cucumoviruses; 10. Potyviruses; 11. Viral determinants involved in Luteovirus-aphid interactions; 12. Approaches to genetic engineering of potato for resistance to potato leafroll virus. Part IV: Ecology, epidemiology, and control: 13. Bemisia - pest status, economics, biology, and population dynamics; 14. Whitefly-borne viruses in continetal Europe; 15. Transmission properties of whitefly-borne criniviruses and their impact on virus epidemiology; 16. Classical biological control of Bemisia and successful integration of management strategies in the United States; 17. Interference with ultraviolet vision of insects to impede insect pests and insect-borne plant viruses; 18. Bionomics of Micrutalis malleifera fowler and its transmission of pseudo-curly top virus.