Spider Bling

Spider's are pretty amazing.  Take Charlotte in the book Charlotte's Web by E.B. White.

Charlotte was a barn spider, probably from the writing spider family or Argiope.  She created a new web each night probably after eating her web each evening.  (Quick factoid: although it wasn't in the book, spiders do eat their webs. There's valuable nutrients in a spider web plus pollen, moisture and bug parts which help feed spiders.)

What was amazing about Charlotte was the designs she made in her web. She added Bling!

Here's a picture of a typical black and yellow garden spider.  I don't have a barn for barn spiders so when I see these spiders, I call out "Hello Charlotte!!".  They create amazing oval webs, strung between bushes, trees, houses ~ sometimes at face level. Grrrrrrr. 

GNU Free Documentation License, Version 1.2, user: Grapnell

This guy, also from the Argiope family, was photographed in Tanzania.  

GNU Free Documentation License, Version 1.2, Muhammad_Mahdi_Karim

 Note the heavy weaving in the center and how it is used as camouflage.  She's got Bling, just like Charlotte. :)  I wonder if there are some words hidden in there......

(CC BY-SA 3.0) user:User:Kepper66

Here's a "Charlotte" living in Iowa, who blinged up her web with an almost X.  Thankfully, this web is at knee level.... 

My "spider bling" has a scientific name: stabilimentum.  Not only do spiders design their stabilimentum as they please, some add twigs, debris and insect carcases to make the web more attractive.  I know, I know: dead insect parts and pieces *isn't* attractive to us but if we were spiders, they'd be simply lovely.  Charlotte held off on dead bodies in her creations although I bet little boys would love that added to Charlotte's Web!!

Back to the topic at hand.  The exact purpose of stabilimentum is up for discussion.  As we can see, it is used differently by different species of spiders.  Some stabilimentum has been shown to reflect ultraviolet light which can either deter predators or attract prey.  Imagine putting a landing strip on your web, advertising to flies "Hey, land here! It's safe, honest!!".  At the same time, imagine signalling to birds "Don't fly here, its all sticky and goopy."  

For orb spiders who create webs of golden reflective silk, this would not be why they use stabilimentum.  They may use it to reduce vibration and / or increase strength in their web.  Think rubber bands: webs need to flex and give to stay stable and hold prey while trapping and sticking to them as they struggle.  

Our Tanzanian writing spider used their stabilimentum to camouflage their outline (tricky, tricky!!) and make them appear larger to birds or other insects interested in eating them.  Also, scientists theorize it may be in webs because spiders create excess silk that needs to go somewhere.  Okay, that's not the most creative explanation but logical.  

How do spiders know to make these structures?  They just know. Pretty amazing!!

This growing season, keep your eye out for spider bling.  If you see a web with bling, take a minute and try to guess why the spider used it in their web.  If you have a pair of glasses that can detect ultraviolet light like that character in Star Trek, the Next Generation: look for little landing strips outlined in ultraviolet light. 

Stabilimentum aka Spider Bling!!  It's amazing stuff.