For the village on the island of Lesbos, see Eresos. Eresus, also called ladybird spiders, is a genus of velvet spiders that was first described by Charles Athanase Walckenaer in 1805. Members of the genus formerly called Eresus cinnaberinus or Eresus niger are now placed in one of three species: Eresus kollari, Eresus sandaliatus and Eresus moravicus.