Orb-weaver spider (Araneus ventricosus) Photo By 池田正樹 (talk) – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=7174023

Dear Readers, if the spider above looks kind of familiar, it’s no surprise – this spider is from China, Japan and Korea, but is closely related to ‘our’ garden spider, Araneus diadematus. However, unlike ‘our’ orb weaver, this species builds its web at night, and catches mostly nocturnal insects. In the morning, it eats its web and presumably sits under a leaf somewhere, dozing, digesting, and waiting for dusk to fall.

The spider has been the subject of several scientific studies – it produces something called flagilliform or dragline silk, which is the most flexible of all spider silks, and the gene for this has been isolated. No doubt someone somewhere is planning on creating superspiders who produce shedloads of this valuable commodity, which humans haven’t yet found a way to replicate.

The spider also has highly-developed eyes that are adapted for night vision, and may be amongst the first invertebrates to have a primitive optic nerve.

But! The latest research on this spider (which I suspect is too popular amongst scientists for its own well-being) is that the arachnid appears to use fireflies to lure other fireflies into its web. Scientist Xinhua Fu, of Huazhong Agricultural University in China noticed that male fireflies seemed to be caught in the webs of the orb weaver spider, but females didn’t. A series of experiments found that webs with a spider and a flashing male firefly caught more fireflies than either an empty web, or a web with a non-flashing firefly. But there was more. Male fireflies, when caught, seemed to change their flashing signal to one that more closely resembled that of a female – females send out a single pulse, males a double pulse. So other male fireflies were approaching the web because they thought it contained a female, and were caught themselves in turn.

How, though, is the male’s signal being changed? It isn’t clear yet, but one theory is that the spider’s venom changes the way that the male signals. It’s interesting that the firefly isn’t killed by the venom, as you would normally expect an animal caught in the web to be. It would be interesting to know if the spider’s behaviour towards fireflies is different from that of other prey. Could they be ‘deliberately’ choosing to treat fireflies in a particular way? The mind boggles.

You can read the original report here.