Redescription and oviposition behavior of an orb-weaver spider parasitoid Hymenoepimecis cameroni Townes, 1966 (Hymenoptera: Ichneumonidae)

摘要

Strategies to invade and exploit hosts for survival are an essential part of the parasitic lifestyle. Species of the Polysphincta genus group (Hymenoptera: Ichneumonidae), which utilize spiders as hosts, are examples of parasitoids that present several behavioral strategies in host immobilization and egg laying. In this study, we characterized the oviposition behavior of the Darwin wasp Hymenoepimecis cameroni Townes, 1966 (Hymenoptera: Ichneumonidae) on their host spider, performed the taxonomic description of the female, and redescribed the male parasitoid. We observed eight H. cameroni females endeavoring to parasitize young Leucauge volupis (Keyserling, 1893) spiders. Each female made up to 12 successive attempts at oviposition, totaling 36 observed attacks, with only two successful attacks. The main oviposition behavior of H. cameroni individuals consists of flying close to the web and performing a direct attack on the spider, which often results in the spider escaping into the vegetation. We observed that in seven events where the spiders fled into the vegetation, the individuals of H. cameroni adopted a second strategy, which consisted of hanging from the hind legs in the web hub. This observation showed that the females of H. cameroni have the ability to modulate the oviposition strategy after a failure in the initial attack. The pattern observed for the attack of H. cameroni indicates that the ability to adjust the approach could be specific to the behavioral habits of L. volupis.