Parasitoidism in the heights: behavioral modification of spider induced by Darwin wasps at the Colombian Andes

Abstract

Abstract Hymenoepimecis is a genus of Darwin wasps within the Polysphincta genera group (Hymenoptera: Ichneumonidae: Pimplinae) known for being ectoparasitoids of a broad spectrum of spiders. This parasitoid-host interaction results in a modified web known as cocoon web, which provides shelter and support for the wasp during its pupal stage. In this study we describe for first time the interaction between Hymenoepimecis castilloi Padua & Sääksjärvi (Hymenoptera: Ichneumonidae) and the host spider Leucauge mariana Taczanowski (Araneae: Tetragnathidae) in the Colombian Andes. We provide new records of wasp genus distribution and reported the behavioral modifications induced in their spider host. Web modifications were found in the webs of solitary and aggregated parasitized individuals. We found an absence of adhesive spirals and webs that were connected to vegetation by multiple threads in all cocoon webs, which was not seen in webs of non-parasitized spiders. All parasitoid cocoons were observed hanging on a vertical line in the hub of the cocoon web. As previously described for other interactions between spiders and wasps, we believe that this modified web design is related to increased web strength, which favors parasitoid development during the pupal stage.