Orb weaver spiders may lace webs with toxins

[Still Waters]

Orb weaver spiders are known for their big, beautiful webs. Now, researchers suggest that these webs do more than just glue a spider’s meal in place — they may also swiftly paralyze their catch.

Biochemical ecologist Mario Palma has long suspected that the webs of orb weavers — common garden spiders that build wheel-shaped webs — contain neurotoxins. “My colleagues told me, ‘You are nuts,’” says Palma, of São Paulo State University’s Institute of Biosciences in Rio Claro, Brazil. No one had found such toxins, and webs’ stickiness seemed more than sufficient for the purpose of ensnaring prey.

The idea first came to him about 25 years ago, when Palma lived near a rice plantation where orb weavers were common. He says he often saw fresh prey, like bees or flies, in the spiders’ webs, and over time, noticed the hapless animals weren’t just glued — they convulsed and stuck out their tongues, as if they’d been poisoned. If he pulled the insects free, they struggled to walk or hold up their bodies, even if the web’s owner hadn’t injected venom.

https://www.sciencenews.org/article/spiders-poisonous-webs-neuro-toxins-genes

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Revealing the Venomous Secrets of the Spider’s Web

https://pubs.acs.org/doi/10.1021/acs.jproteome.0c00086