Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon

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  Beyond Venom and Constriction: Bite Performance and Trophic Ecology in the Genus Drymarchon Abstract Snakes exhibit extreme cranial kinesis that facilitates ingestion of prey with large cross-sectional area, but this ability is widely predicted to reduce bite performance due to decreased structural rigidity. Consequently, most large-bodied snakes rely on envenomation or constriction to subdue prey prior to ingestion. Species within the genus Drymarchon represent a notable exception: these large, non-venomous, non-constricting snakes routinely consume a wide range of prey, including large and potentially dangerous vertebrates, using only simple seizing and pinioning behaviors. Here, we quantify bite performance in three species of Drymarchon ( D. corais, D. couperi, and D. melanurus ), examine morphological predictors of biting performance, compare biting pressure to constriction pressure in similarly sized snakes, and synthesize dietary records across the genus. Our results sh...

Social and colonial spiders as model systems for host-symbiont interactions at different levels of organization

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Social and colonial spiders as model systems for host-symbiont interactions at different levels of organization

Symbiotic interactions, which run the gamut from microbial assemblages to synergistic or antagonistic interactions with macro-organisms, can shape ecological communities across levels of biological organization, from solitary hosts to large social groups. Web-building spiders have given rise to two types of social systems: outbred colonial orb weavers, which form web complexes with a modular structure and no cooperation, and inbred social species with tightly knit societies displaying cooperation within shared communal webs. We synthesize recent findings on the macro- or micro-organisms that colonize individual spiders or their living quarters in social and colonial species, highlighting their potential contributions to population stability and vulnerability as a function of the hosts’ social and breeding system. The tightly knit societies of social spiders facilitate microbial homogenization and prolonged associations with potential macro-symbionts, whereas colonial spiders likely maintain more transient relationships with heterospecific inquilines. Individual spiders and colonies must navigate relationships with diverse inquilines, ranging from mutualistic fungi that attract prey to their webs to behavior-manipulating parasitoid wasps. Macro-symbionts exploit colony resources, including nest materials for living quarters, spider-caught prey for food, or feed on spiders or their eggs. Micro-symbionts seem to colonize all tissues or materials, except eggs, with some having greater affinity for specific host substrates. These systems offer insights into broader ecological and evolutionary questions, including the role of symbiosis for host population stability, adaptation, and ecosystem function. Understanding how host-symbiont dynamics scale from individuals to communities provides critical perspectives on the mechanisms that structure cooperative and antagonistic interactions in nature.

Cassidy, S. T., & Avilés, L. (2026). Social and colonial spiders as model systems for host-symbiont interactions at different levels of organization. Current Opinion in Insect Science, 101521. https://doi.org/10.1016/j.cois.2026.101521