New Types of Behavioral Manipulation of Host Spiders by a Parasitoid Wasp

The larva of the parasitic wasp Zatypota sp. nr. solanoi induces its host spiders Anelosimus spp. to modify its web in ways not seen in normal webs of this species or in any other species, providing apparent protection and support for the wasp’s cocoon by covering the entire web with a protective sheet and adding a central platform and opening a space below in the enclosed tangle, where the larva suspends its cocoon. These modifications differ qualitatively from those induced by a congeneric wasp. Parasitized spiders appeared to adjust modified web construction behavior to local conditions, implying that larval manipulations may occur at higher rather than lower levels of behavioral control (e.g., eliciting overall design decisions, rather than particular motor patterns).