In an article entitled, “Genetic mapping of two QTL from the wild tomato Solanum pimpinellifolium L. controlling resistance against two-spotted spider mite (Tetranychus urticae Koch) published online on the 17th August in the journal of “Theoretical and Applied Genetics,” Maria Salinas and her seven associates have reported that resistance against this destructive mite is controlled by a major locus contributed by S. pimpinellifolium. Furthermore, their investigation revealed that the resistance is regulated by some minor loci of unknown location in the genome of this wild tomato. They used F4 population to identify a genomic region of 17 cM on chromosome 2. Flanking the region are located two simple sequence repeat markers resident on which is Rtu2.1, one of the major QTL involved in the spider mite resistance.