Behavioral manipulation of a “Trashline Orb-weaving spider” Cyclosa fililineata (Araneidae) by the parasitoid wasp Zatypota riverai (Ichneumonidae: Pimplinae)

Abstract. In this study, we report a new interaction of the wasp Zatypota riverai Gauld, 1991 (Ichneumonidae) parasitizing the spider Cyclosa fililineata Hingston, 1932 (Araneidae) and we describe the modified spider web. Our results show that parasitized spiders build modified webs that are clearly different from normal capture webs. This modified web presents several additional lines at the center of the web, forming a disk-like structure that was also observed in modified webs of other host orb-weaving spiders. To our knowledge, Z. riverai (this study) and Z. kauros Gauld, 1984 are the only two species of the genus Zatypota that use spiders from different families as host. However, the unexpected host C. fililineata could be an accidental host, since in the same region there are two of the typical hosts, the theridiid spiders Anelosimus baeza Agnarsson, 2006 and Theridion sp.