St. Andrews Cross Spider

Male St. Andrew's cross spider(Argiope keyserlingi)

 St. Andrews cross spider(Argiope keyserlingi) is a non venomous species of spiders found in South Asia and Australia. St. Andrews cross spider can be identified from its web which has white, sturdy, X-shaped knitting called Stabilimenta. It makes the web stronger and also increases the chance of catching a prey. The female is larger than the male and has yellow and white stripes. This is called sexual size dimorphism. The male is found sitting on a female's web. It is common to  find multiple males on a female's web. Once I saw the female attack and trap the male that was sitting on its web. 

Female Argiope keyserling (top)

They sit on the web with pairs of legs together in the shape of "X". In Bangalore I find them coming to my balcony after rains due to October heat and again in the summer season.  

In November 2019 I found 2 such spiders in my balcony. I was familiar with this species, it used to creep me out. When I observe it closely in my balcony and the fear was numbed. I watched the spiders rebuilding their webs multiple times after stormy nights, for days it survived without catching food yet, It rebuilt each node of the web, and the stabilimenta.

Female (bottom)

I have noticed that these spiders make very fast movements and switch between the sides of the web when touched. It is hard to tell how they do, unless I can capture it in slow motion. It looks like they switch through the center of the web that has very small holes.

The X-shaped stabilimenta

St. Andrews cross spider eating raisins

 

I tried feeding it by giving it raisins. I scraped out the fleshy part with a tooth pick and stuck it on its web. I didn't go for it. Upon flicking the raisin piece vigorously to mimic a struggling insect the spider went for it. For about half a minute it just rolled it around to examine it. Then it wrapped it in a web and hung it there. For tying the prey, they shoot a sort of sheet. Scientists are investigating the function and evolution of web decorations, sperm competition, sexual size dimorphism, cryptic female choice, and the role of pheromones in mating behavior. Nature can inspire us in a ton of unimaginable ways. Just stop by and observe...

One morning I spotted a Jumping spider giving a death stare to the St. Andrews cross spider. The small St. Andrews cross spider had built its web on the pigeon net, and the stabilimenta was very dense and in shape of a slice instead of X-shaped. Nature always gives me these surreal scenes, leaving me craving for more...Feast for your eyes-

Jumping Spider staringat St. Andrews cross spider

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