Obligate argyrodine kleptoparasites (Theridiidae, Araneae) exploit heterospecific spider webs for meals and shelter. Argyrodine spiders are a mannequin lineage for the examine of kleptoparasitism and associated methods, but knowledge on the behaviour of the vast majority of the over 250 argyrodine species is missing. Right here, we assist fill that data hole by documenting the pure historical past of two poorly-known species. We studied Argyrodes pluto and Neospintharus baboquivari within the webs of two different cobweb spiders, the western black widow (Latrodectus hesperus) and Tidarren sisyphoides, throughout 4 websites in southern Arizona. Argyrodes pluto completes its life cycle in L. hesperus webs and specialises on host egg sacs, displacing them to the periphery and feeding on eggs and juveniles; this behaviour seems important for its copy. Neospintharus baboquivari happens gregariously in each host webs, gleaning small prey. In distinction, N. baboquivari is reportedly a solitary araneophage within the colonial orb webs of Philoponella oweni. We quantified egg sac displacement and describe foraging, mating, egg sac development and interactions with parasitoids and predators. These findings reveal novel pure historical past data and increase our understanding of argyrodine behavioural plasticity.
Cowles J, Agnarsson I (2025) Thieves and freeloaders: Argyrodine kleptoparasites invading cobwebs (Theridiidae) within the arid south-western USA. Biodiversity Information Journal 13: e172851. https://doi.org/10.3897/BDJ.13.e172851
