Host Behavioural Manipulation of Spiders by Ichneumonid Wasps

Distinct movement patterns generate stages of spider web building

“…In addition to human manipulation, the larvae of several species of Ephialtini, a tribe of ectoparasitic wasps, can alter ecdysone levels in spiders to pause web building before capture spiral construction, indicating that neuromodulation may contribute to encoding the transition from radii to spiral construction. 34 Similar internal states may regulate the progression of web phases, even in the presence of ambiguous or noisy tactile sensory input, perhaps explaining the extraordinary robustness of this complex behavior in various environmental contexts. 35 Integration of sensory input and internal states is likely integral to the fidelity and robustness of web construction, although the relative contributions of reflexive and cognitive factors to this behavior remain to be addressed.…”

Distinct movement patterns generate stages of spider web-building

“…These drugs alter neuromodulatory pathways in the brain, which indicates these pathways may participate in web-building behavior to varying degrees depending on web-stage. In addition to human manipulation, the larvae of several species of Ephialtini , a tribe of ectoparasitic wasps, can alter ecdysone levels in spiders to pause web-building prior to capture spiral construction, indicating neuromodulation may contribute to encoding the transition from radii to spiral constrution 34 . Similar internal states may regulate the progression of web phases even in the presence of ambiguous or noisy tactile sensory input, perhaps explaining the extraordinary robustness of this complex behavior in varying environmental contexts 35 .…”

Parasites of spiders: Their impacts on host behavior and ecology

“…There are numerous reports of species from the Polysphincta clade of the subfamily Pimplinae (Hymenoptera: Ichneumonidae), all koinobiont ectoparasitoids of spiders, manipulating the web building behavior of their hosts (Gonzaga et al 2017;Weinersmith 2019). When these parasitoids molt into their final larval instar, the host constructs a modified web which is often similar to the host's moulting, oviposition, and/or overwintering webs, on which the parasitoid larva kills and consumes its host and affixes a pupal cocoon (Korenko & Peka´r 2011;Korenko et al 2013;Gonzaga et al 2017;Weinersmith 2019). Similar behavioral alterations have been observed in Anelosimus spp.…”

“…Matsumoto (2009) found that removal of the protective modified web produced by Agelena limbata Thorell, 1897 when parasitized by Brachyzapus nikkoensis (Ichneumonidae) increases predation risk on the parasitoid before eclosion. The modified webs produced by parasitized spiders are often less effective at intercepting prey, but rather provide increased stability and safety for the parasitoids' cocoons (Gonzaga et al 2017). Across diverse host-parasitoid systems, these analogous manipulations may result from similar underlying mechanisms, like the injection of psychotropic compounds related to or precursors of ecdysteroids (Takasuka et al 2015;).…”