Genus Nesticus Thorell, 1869

Diagnosis. Nesticus resembles Aituaria Esyunin and Efimik, 1998 and Carpathonesticus Lehtinen and Saaristo, 1980, but can be distinguished by the following characters (Esyunin and Efimik, 1998; Le Peru, 2011): 1, Nesticus is distinguished from Aituaria and Carpathonesticus by the embolus long, thin, without modified apex; 2, the median apopysis moderately longer in Nesticus than in Carpathonesticus; 3, the paracymbium distally entire in Nesticus,butmorepointedin AituariaandCarpathonesticus; and 4, epigynal plate wide posteriorly in Nesticus, but wide anteriorly in Aituaria and Carpathonesticus .

Distribution. Nesticus includes 138 species, worldwide distributed, mainly in the United States of America, Japan, and China. Only nine species are present in South America, especially in French Guyana, Brazil, Chile, Argentina, and Uruguay. In Argentina, only three of these species were reported (World Spider Catalog, 2015).