We report for the first time the existence of eggsac recognition and maternal care in Loxosceles gaucho. Spiders confronted simultaneously with their own and foreign eggsacs stay closer to their own eggsacs. This is unexpected since eggsac recognition should evolve among species with clumped distributions, high maternal investments and few breeding opportunities, features not present in this species. Despite this recognition, spiders with a single eggsac make no distinction between their own and foreign eggsacs: they adopt eggsacs from sympatric, conspecific females, and take care of them as their own. It seems that there is a readiness to perform maternal care that overrules the recognition system. We describe oviposition behavior and compare it with other descriptions in the literature. Seven behavioral characters related to eggsac building and/or guarding are mapped onto available phylogenies. Maternal care behaviors are quite conservative among spiders, useful for the grouping not only of families, but also of higher order ranks.