We are in mid-September and whether the “feels like” temperature agrees with the calendar or not, it is fall in Florida. Now is a great opportunity to get outside and notice the arachnids around us.
Orb-weaver spiders enjoy great renown thanks to the movie, “Charlotte’s Web.” That special orb-weaver wove messages into her webs to alert the farmer about a pig’s special purpose. While spiders do not yet weave words with their silk some do create unique patterns referred to as stabilimentum.
Whether these unusual patterns of heavy silken fibers act to strengthen or stabilize the webs or serve more as a visual deterrence so birds do not fly through the spider’s handiwork is still being researched. Another thought is how the stabilimentum mimics the unseen patterns in flowers which can be viewed under ultraviolet light. Flying insects recognize these patterns as the “runway” to a nectar source and thus are lured right into the spider’s web and waiting jaws.
Perhaps the criss-cross patterns or zig-zagging fibers camouflage the spider from its own predators as it hangs defenseless waiting for its own meal? From x’s and spirals to doily-like designs, it hardly seems a leap for a spider to knit a simple word or two. While such folly makes for good stories, a spider’s web is the stuff of science.
Spiders manipulate this remarkable protein which makes up the webbing as they pull it from their bodies. The stretching action makes those gossamer threads tough and elastic. Some are sticky, but not all. Non-sticky silk is used for the outer portions of the web as well as walkways and egg sacs.
Garden orb-weavers create the big, showy webs where you may have noticed peculiar webbed features. The yellow garden orb-weaver sits on a zipper-like stabilimentum that reaches above and below her pointed, oblong abdomen. During the fall months, these spiders are large and the webs obvious, but when young and small, this spider spins a tiny lacy disk that it sits on.
The shiny, metallic-like silver garden orb-weaver is a beauty to behold. Her large abdomen shines like chrome and her striped, hairy legs are held in pairs as she sits on her web. Her stabilimentum includes four, short zigzags that she sits within, almost as though she is holding them up.
Like a silver garden orb-weaver, the Florida garden spider boasts shiny, silver coloration, though not as much as the former. The banded garden orb-weaver also sports some shine, but its abdomen is colored with thin concentric bands that almost reminds one of a woven basket.
Each of these spiders spins a peculiar design element into its web which can help you identify the spider you are seeing. The banded and yellow garden make the zipper-like patterns while the silver garden and Florida garden will have the four, cross-like markings in their webs.