Come into My Parlor

"Come into My Parlor"

The manner in which predators bring down their victims often seems cruel and inhumane. It must be remembered, however, that the intent of the predator is always to subdue its prey as quickly as possible. It matters little whether the carnivore's purposes are altruistic, because the speedier and more efficient the kill, the more compassionate it appears.

The process through which prey animals become food for carnivores is extremely important in maintaining a balanced ecosystem. In almost every habitat where the predator has been depleted, usually by man, the natural prey multiplies beyond control, and many die of starvation because there is not enough food to go around. On the other hand, if predators killed unnecessarily in the wild, they would soon run out of food and precipitate their own destruction.

The lion, the tiger, and the leopard are prize examples of talent and skill in hunting, but the most accomplished hunter of them all is the lowly spider. The great cats, which fail to capture their prey many more times than they succeed, could indeed learn a few tricks from the modest—sized arachnid.

Much of the spider's efficiency in hunting is the result of advance planning. Basic to the spider's predatory proclivity is its instinctive, quick, and accurate skill in web making. It may be an untidy sheet of web, a silken tube, several sticky strands, or an intricate geometric orb, sometimes six and a half feet in diameter, containing up to 1,000 feet of silk. The spider will produce whatever type of web serves it best as home, storage area, camouflage or decoy, and, of course, trap.

Beyond its skill of building a web in which to lie in wait for victims, many spiders exhibit special techniques that warrant the admiration of every creature except their unfortunate prey. There is the spitting spider, which fires a sticky thread from its jaws to pin down its prey. The bola, or angling spider, produces a weighted thread, or fishing line, laced with blobs of sticky gum. When it feels the vibration from a potential captive, it whirls the line and reels in whatever luckless prey has made contact with a globule of gum.

The water spider, finding its prey in lakes, ponds, and ditches, fashions a diving bell out of tightly woven silk, into which it carries a supply of air bubbles. The Mediterranean orb spider has perfected a defensive tactic by which it arranges the carcasses of insects in two piles that match the shape and color of its own body. The decoys are placed strategically on the web so that an enemy has only one chance in three of catching the real thing. While the predator is concentrating on the decoy, the spider works out a strategic retreat. Each spider has refined its skills so expertly that by the time the spider needs a meal all that remains to be done is to start eating.

More than 40,000 known species of spiders are living today. The spider is largely responsible for controlling the insect population beyond the scope of spray, swatter, and exterminator. So well adapted is this predator to killing and devouring its prey that, in England and Wales alone, the weight of all the insects consumed by spiders in a single year is greater than that of all the human inhabitants of these countries combined.

There is no doubt that the spider is indeed the greatest of hunters and on whom we have grown to depend. The arachnid is often unaware of this, as an incident in Honduras might illustrate. The workers on the banana plantations complained of an alarming overabundance of spiders, and this was undermining their efficiency, to say nothing of their job contentment. The owners of the plantations, yielding to the workers' complaints, finally had the area sprayed extensively, and the spiders were exterminated.

The natural balance between predator and prey was definitely disturbed, because the next crop was consumed almost entirely by insects that were resistant to spray chemicals! The banana companies quickly imported a supply of spiders to get them out of the ecological mess they had created. No further complaints from employees were recorded.

From the book: 
Our Fascinating Earth