Two virus isolates, T1 and T2, causing necrotic spots on leaves and stems of pepper and tomato, respectively, were isolated in the La Joya valley, Arequipa, Peru, in 2010. These two isolates were inoculated to differential hosts for tospoviruses and showed differential fitness: T1 induced necrotic local lesions in Vigna unguiculata, whereas T2 produced only chlorotic spots. The complete nucleotide sequence of the small (S) RNA from T2 and 1863 bp of the S RNA from T1 were determined. The deduced N protein sequence showed high amino acid identity (97%) between the isolates, indicating that the T1 and T2 are isolates of the same virus. Sequence comparisons indicated that the amino acid sequence of the N protein shared 53. 49-87. 98% identity with known American tospoviruses. Phylogenetic analysis of both the NSs and N proteins revealed that this new tospovirus belongs to the American group. We conclude that this tospovirus should be considered a member of a new species. The name Pepper necrotic spot virus (PNSV) is proposed. © 2012 Springer-Verlag.