“Peste negra” is a disease, caused by tospoviruses, that affects tomato crops in Argentina. Knowledge of the diversity, frequency, and distribution of different tospoviruses is essential for developing a rational control program based on genetic resistance sources. A study of the geographical distribution of tospoviruses affecting tomato crops in Argentina is presented in this paper. The areas surveyed were between the Tropic of Capricorn and 40°S and between longitude 58°W and 70°W. Tospovirus species were identified through double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA), using polyclonal antisera against Tomato spotted wilt virus (TSWV), Groundnut ringspot virus (GRSV), and Tomato chlorotic spot virus (TCSV). From tomato samples that reacted positively with any of the used antisera, 63% were GRSV, 28.2% were TCSV, and 8.8% were TSWV. A differential geographical distribution of tospoviruses was determined. Every plant that tested positive for GRSV was from central and northwest Argentina, while every plant TCSV-positive was from the northeast. TSWV was found only in the Río Negro Valley region in the south of the country. The wide dispersion of GRSV may be related to the spread of Frankliniella shultzei, which transmits this virus more efficiently than other vectors.

The rapid immunofilter paper assay (RIPA) was developed to detect Tomato spotted wilt virus (TSWV), Groundnut ringspot virus (GRSV), and Tomato chlorotic spot virus (TCSV) using antisera against recombinant nucleocapsid (N) proteins of each tospovirus. The two-step RIPA was sensitive enough to detect each species specifically in only 30 min. This technique is proposed as an excellent tool for routine Tospovirus diagnosis and field epidemiological studies.