A note from the Kumamoto International entomology desk.

A note from the Kumamoto International entomology desk.

Autumn is just around the corner, meaning it is time for the jorōgumo (Japanese orb spiders) to enlarge their webs - and size. One has secured an advantageous location on my balcony; I just observed as she used one of her forefeet to transfer water droplets from her web to her mouth (yes, most spiders drink water - today’s rain must be a relief to them). As with other orb spiders, their webs can be extremely large and dense and the silk robust: run a finger across a strand and it feels like a fishing line. Despite their large size, the spider presents no danger to humans (though stumbling into a web can be most unpleasant - like walking through a cotton candy machine). It is nearly blind but very sensitive to vibrations, so try clapping loudly near one to watch its reaction.

I say “she” as only the females build webs. Sexual dimorphism in this species is extreme, like a chihuahua trying to make it with a great dane - the ladies build the webs, and the diminutive guys hang out in the corners, waiting for a chance to get laid without being eaten first. This, in addition to the females’ bright colors, are the origin of its name: “Jorōgumo” would be directly translated as “prostitute spider.” In fact, the jorōgumo has had since Edo times its own yokai meme, which has it that, when females turn 400, they acquire the ability to transform into beautiful maidens, and as such seduce wayward men by playing the biwa and then bind them and do what spiders do with bound prey. So there’s that.

Photos and more info on the spider can be found here: https://en.wikipedia.org/wiki/Nephila_clavata

and more info on the yokai stories here: https://en.wikipedia.org/wiki/Jor%C5%8Dgumo

• William