Web architecture alteration of the orb web weaving spider Metellina merianae (Araneae, Tetragnathidae) induced by the parasitoid Megaetaira madida (Ichneumonidae, Polysphincta group).

The polysphinctine wasp Megaetaira madida (Haliday, 1838) is a koinobiont ecto-parasitoid of spiders of the genus Metellina. Under the influence of the parasitoid's final instar larva, the spider host M. merianae (Scopoli, 1763) built a three-dimensional web architecture, which differed considerably from the capturing orb web. The alteration of spider web behaviour induced by a parasitoid larva in this host-parasitoid pair is described for the first time. [ABSTRACT FROM AUTHOR]