Vertebrate prey capture by Latrodectus mactans (Walckenaer, 1805) and Steatoda triangulosa (Walckenaer, 1802) (Araneae, Theridiidae) provide further insights into the immobilization and hoisting mechanisms of large prey

Spider species across 27 families have been recorded naturally preying upon vertebrates. Intricate three-dimensional webs, predation strategies, and potent neurotoxic venom allow Latrodectus and Steatoda spiders to subdue vertebrate prey that are many times larger and heavier than themselves. Yet, little is known about the behaviour associated with capturing comparatively large vertebrate prey, or how common these predatory events are. We report on two new cases of vertebrate predation by Latrodectinae spiders: a Latrodectus mactans (Walckenaer, 1805) preying on a common house mouse Mus musculus (Linnaeus, 1758) in the USA and a Steatoda triangulosa (Walckenaer, 1802) preying on a Kotschy's gecko Mediodactylus kotschyi (Steindachner, 1870) in Greece. Although predation events on vertebrates by Latrodectus species have been documented in the literature, such events have been sparsely reported for the genus Steatoda. We provide the first record of S. triangulosa preying on M. kotschyi. Such predation events shed light on the multifunctional physiology of the venom and behavioural ecology of these spiders.