Along came a spider...
The sticky strands stretched across my face, nose and eyelids and wrapped themselves over the top of my right ear. I struggled to maintain my composure and control my language, as I swept my hands rapidly around my head trying to disengage from the unseen webbing. The nearly invisible trap had not been set for me, but I had once again fallen prey to Gasteracantha cancriformis, the spinybacked orb weaver spider.
As the Halloween decorations reach their peak in anticipation of the coming invasion of ghouls, ghosts and goblins, a less anticipated but equally fascinating peak in our natural spider webs is occurring, too. Take a walk along any large hedgerow or fence, or just look closely at the bushes and trees along almost any trail or sidewalk. Magnificent, intricate webs are everywhere, some spanning 15 feet or more across. I recently counted 18 of these amazing webs attached to a single tree at the south end of the small parking lot south of Pierce Park pool. They stretched from a lone oak tree across the paved exit to dozens of other trees and bushes. These webs serve primarily to catch small flying insects, which are normally bitten and paralyzed, carried to the center of the web, and eaten. Prey larger than the spider itself may be wrapped up first to assist in the transit.
As spectacular as some of these webs are, even more spectacular is the spinybacked orb weaver itself. At less than half an inch in diameter, it is very small and would go mostly unnoticed except for its large webs. These spiders look more like crabs than arachnids, with colorful protective shells including six “spines” on the outer edges. They are predominantly white or yellow with black or red accents. The spinybacked orb weaver lives in a wide range of places. In the United States it lives in the southern half of the country from California to the East Coast.
These spiders live short lives of less than a year. What we have on Daniel Island at Halloween are mature spiders, which produce the largest webs. Before long they will mate. The males, one third to one half the size of the females, typically “hang out” on single threads of webbing near a web spun solely by the female. When it is courting time, he will “tap” on a female’s web hoping to find a welcome. If his advances are accepted, the two will mate. Within a week or so of mating, the male will die. The female will soon produce hundreds of eggs in an egg sack, which will be carefully wrapped and attached to the bottom of a nearby leaf. Once that work is done, she will also die.
In a couple of weeks, the eggs will hatch. It takes several more weeks before the new spiders leave the egg sack and head out on their own. Young spinybacked orb weavers are very small and spin tiny webs. For the next several months, they will go largely unnoticed. As summer approaches, they will start to resemble their parents and by fall, they will be creating the large webs of autumn.
While the webs can be a little creepy, especially when encountered unexpectedly, the spinybacked orb weaver rarely bites. When it does bite, it is of little danger to a human. Mostly, this remarkably beautiful little spider just gives us fewer flying insects to deal with and some fantastic Halloween decorations, both free of charge. On a personal note, my editor/photographer/wife, upon reading through this piece, remarked that God must have a special place in heaven for female creatures of all kinds.