Advances in Disease Vector Research

We open Volume 7 with a series of four chapters on plant virus transmission by insects. In Chapter 1, Karen Gibb and John Randles present preliminary information about an association between the plant bug Cyrtopeitis nicotianae (Heteroptera: Miridae) and velvet tobacco mottle virus (VTMo V): the only reported instance of mirid transmission of a known virus. Mirids could be considered as likely vectors of plant viruses because they are phytophagous, possess a piercing-sucking-feeding apparatus, have winged adults, and are cosmopolitan pests of a wide range of crops. Surprisingly, however, there are only three plant viruses purportedly transmitted by heteropterous vectors, compared with the nearly 250 by homopterous ones. To what extent these figures reflect actual differences in the abilities of members of the two suborders to transmit plant pathogens remains to be determined. Compared with the Homop tera, the Heteroptera have been ignored by researchers as potential vectors of plant viruses. The authors are quick to point out that additional studies are needed before generalizations can be made about virus-mirid-plant interactions and that virus transmission by mirids is not easily characterized using the conventional transmission criteria and terminology established for such homopterous vectors as aphids and leafhoppers. Transmission of VTMoV by C. nicotianae appears to have characteristics in common with both nonpersistent noncirculative and circulative (persistent) transmission.

Texte du rabat

This series explores how vectors (carriers of disease agents, such as insects) acquire, carry and subsequently transmit pathogens to hosts. It covers the spectrum of vectors, including carriers of plant pathogens as well as medically related pathogens. The Chapters in Volume 7 include: 1. K. Gibb, J.W. Randles: Transmission of velvet tobacco mottle virus and related viruses by the mirid Cyrto- peltis nicotianae. 2. N. Carter, R. Harrington: Factors influencing aphid population dynamics and behavior and the consequences for virus spread. 3. R.H. Bagnall: Cyclic epidemics of aphid-borne potato viruses in Northern seed-potato-growing areas. 4. C.J. Andrews, R.C. Sinha: Interactions between barley yellow dwarf virus infection and winter-stress tolerance in cereals. 5. J.R. DeLoach, G. Spates: Artificial diets for blood feeding insects: a review. 6. I. Maudlin: Transmission of African trypanosomiasis: interactions among Tsetse immune system, symbionts, and parasites. 7. C. Chastel, I. Humphery-Smith: Mosquito spiroplasmas. The first four chapters cover topics in plant virus transmission by insects. The final three chapters focus on human and animal disease associations with bollid-feeding flies.

Contenu
1 Transmission of Velvet Tobacco Mottle Virus and Related Viruses by the Mirid Cyrtopeltis nicotianae.- Characteristics of Transmission.- The Paradox of Persistence.- Relationship of Virus Distribution to Transmissibility.- Conclusion.- References.- 2 Factors Influencing Aphid Population Dynamics and Behavior and the Consequences for Virus Spread.- Weather.- Biotic Factors.- Crop Management.- Summary.- References.- 3 Cyclic Epidemics of Aphid-Borne Potato Viruses in Northern Seed-Potato-Growing Areas.- The Curl in Potatoes1750 to 1905.- Potato Leaf Roll.- Potato Mosaic.- The Persistent PLRV and Nonpersistent PVYDifferent Cycles, Different Aphid Vectors.- References.- 4 Interactions Between Barley Yellow Dwarf Virus Infection and Winter-Stress Tolerance in Cereals.- Virus and Vectors.- Epidemiology.- Effect of Virus on Winter Cereal Survival.- Metabolic Changes Due to BYDV in Cereals.- Conclusions.- References.- 5 Artificial Diets for Blood-Feeding Insects: A Review.- Classification of Blood Dietary Studies.- Approaches for Dietary Studies.- Development of Artificial Diet for Glossina and Stomoxys.- Diets of Lipid-Free Hemoglobin.- References.- 6 Transmission of African Trypanosomiasis: Interactions Among Tsetse Immune System, Symbionts, and Parasites.- Experimental Studies of Tsetse Infection Rates.- Mechanisms of Susceptibility to Trypanosome Infection.- Conclusion.- References.- 7 Mosquito Spiroplasmas.- History.- Taxonomy.- Methods of Study.- Biological Properties of Msp.- Ecology of Msp.- Concluding Remarks on Msp Ecology.- Pathogenicity.- Creutzfeldt-Jakob Disease (CJD) and Spiroplasmas.- Mechanisms of Msp Pathogenicity.- Potential for the Use of Msp in Mosquito Vector Control.- Summary and Conclusion.- References.