Bug of the Week returns to the land of tropical sun where we recently caught up with fluid-squirting termites, fungus gardening ants, amorous peacock butterflies, butterflies dining on pipevines and passion vines, and fierce stinging ants defending their leafy home. On a small island in the Turneffe atoll we get up-close and personal, not with an insect, but with a gorgeous eight-legged predator of remarkable enterprise, the golden silk spider. This mistress of entrapment is found from North Carolina to Argentina and on islands in the Caribbean Sea. When it comes to building a web to trap hapless prey, the gargantuan size of the golden silk spider’s three to six foot snare is challenged in size by few other than that of the black and yellow garden spider in the Western Hemisphere.
The beautiful femme fatale featured in this episode constructed her web near a brackish lagoon where zooming damselflies and blowflies filled the air. Over the course of a day, I observed several two and four winged victims in the ginormous web. Unlike many of her kin, the golden silk spider does not construct and deconstruct her web on a regular basis. Repairs due to collisions by carless birds or other random destructors are made as needed. While many web building spiders wrap their victims in silk to subdue them for later consumption, the golden silk spider simply devours her prey after it has been snared. The first step in the gruesome process of eating her catch occurs after the victim is dead. The spider spews potent digestive fluids over the surface of the deceased. A pair of small finger-like pedipalps is used to manipulate the prey while powerful fangs macerate the pulpy mass. Digestive enzymes break down and liquefy tissues which, along with small food particles, are imbibed and travel into the digestive tract of the spider. Yum!
For denizens of the New World tropics, keeping cool under a relentless sun is challenging for arthropods as well as humans. Authors H.V. Weems Jr. and G.B. Edwards Jr. describe three ways the golden silk spider survives extreme heat in its indigenous range. Unlike many web spinners with the traditional bulbous abdomen, the golden silk spider cuts a slender profile with her narrow tapered abdomen. By aligning her posterior parallel to the rays of the tropical sun, she can reduce the amount of direct sunlight impinging on her slender body. Her second keep-cool trick may be to hold and manipulate a drop of liquid with her fangs, allowing it to evaporate and cool her body. The third way this beauty beats the heat is to employ a “magic mirror” similar to the shiny silver shields placed inside a car’s windshield to redirect the sun’s strong rays. Here’s how it works. While the polka dotted abdomen of the golden silk spider is a wonder to behold, her remarkable carapace, the silvery cover on her back, is thought to reflect sunlight away from the spider, thereby allowing it to remain cooler in hot tropical sunshine. Even when cooling off, this beauty is one hot spider.
The golden silk spider does not wrap its prey, unlike this black and yellow garden spider that will save the meal for later.
We thank the hearty crew of BSCI 339M, ‘Mayan Culture and the Interface between Tropical Rainforests and Coral Reefs’, for providing the inspiration for this Bug of the Week. The marvelous Featured Creature ‘Golden silk spider, Nephila clavipes (Linnaeus) (Arachnida: Araneae: Tetragnathidae)’, by H.V. Weems, Jr. and G.B. Edwards, Jr. was used as a reference for this episode.
Read more about this marvel at the following web site: http://entnemdept.ufl.edu/creatures/misc/golden_silk_spider.htm