Résumé
The first report of a geminivirus-induces disease in tomato, #Lycopersicon esculentum# Mill, occurred in 1989 in Guadeloupe as a chlorosis infection. Then, the disease spread over all the island up to 1993 where it is now endemic. At the same time, #Bemisia argentifolii# was identified and important populations were recorded. A survey, combining the incidence of the disease and the presence of the whiteflies was conducted in order to evaluate their real impacts in 1996-97. The identification of the virus infection was made by symptom observation and by ELISA tests and the characterization of #B. argentifolii# by isoenzymes (esterase) and biotest (silverleaf symptom induction). Everywhere in Guadeloupe, the tomato plants expressed similar symptoms of mosaic, leaf distortion, leaf rolling and sometimes severe stunting. The rate of contamination fluctuated from 50-100% to 10-30% in relation with surrounding conditions. Field samples were selected and maintained by grafting to tomato in order to conduct a biological and molecular characterization of the virus. At the same time, the studies on the species identification and dynamic of the populations of #Bemisia# were carried out on tomato and cucurbit. The characterization of the collected whiteflies confirmed the presence of #Bemisia argentifolii# everywhere in the island. A correlation between the spread of the disease and the presence of #Bemisia argentifolii# was analysed