Life Between The Tides (1970s)

is incalculable. And yet for many such fascination lies in the patterns which they inherit and which seem to determine almost everything they do from birth to death. Thus with an almost perfect example of these built-in wiredin behavior patterns usually called instincts. This is the male of the species, distinguished by his very long and bulbous head. And this the female. Our tale is really about her. How driven by her female beetle instincts, she rolls cradles for her young. Her building materials like her dieted to the leaves of the oak and the chestnut tree. But those she selects for her cradles also have to be of a particular size and texture. This one, it seems, will do. She begins, as any tailor would, by measuring a pattern. So many paces up and so many to the side. Man must have learned to measure in such a way that the Beatles arithmetic is inherited. She simply follows the coded instructions in her genes. Approximately 4 in from the tip, she begins to saw away. Her chief cutting tools being her mandibles, jaws that bite not up and down, but sideways. With these sharp instruments, she quickly shears through half the leaf, right up to the main vein. At this tougher obstacle, she hacks away for a while. then crosses over to the other side and continues sawing. And now having carved out a pattern, she works her way back to the center and resumes her attack on the main vein. Her object is to cut off the leaf supply of water and nutrients in order to soften it. But if the leaf is not to break off altogether and her work ruined, the surgery has to be precise. And it is just that. And now for a short time she rests while the leaf hangs in the sun going soft and limp. But when she senses in some unexplained way that the process has gone far enough, she crawls around to the underside of the leaf and begins to bite a series of notches in the main vein. notches that will break the back of the leaf and make it possible for her later to roll it up. And remark the intervals between the notches will prove to be in direct proportion to the circumference of the roll. The next stage in the operation follows logically from the one before and that is the cutting of notches in the branch veins. Notches that will serve as hinges and enable her to fold the leaf in two before rolling it. And only after she has traveled up and down the leaf making these notches is she ready to fold. How enormous an undertaking this is for a creature less than a third of an inch long only becomes apparent when we see leaf and beetle in [Music] perspective. The leaf is 15 times the length of its body. Relative to a man, it is four stories high. Relative to his weight, it is many [Music] tons. It takes her about a half an hour to complete the folding of the leaf. after which she begins the formidable task of rolling it up. Her coordination throughout is flawless. Head, snout, thorax, and abdomen all come to the aid of its six powerful legs in pushing the roll forward. And there's never a sign of slippage. You are [Music] fumbling. The bulkier the roll becomes, the more danger there develops of its buckling, of its coming loose, especially since the ends are of unequal width. But the beetle has a ready solution for this, too. She bites tiny wedges in the folds and pleats them. A device that not only keeps the roll tight and even, but helps to prevent it from coming apart. What follows next is perhaps a pure example of an inherited behavior pattern. For after completing two turns of the roll, she suddenly stops and bites a slit in the center. In this slit, she inserts her ovapositor and proceeds to lay a single egg. As we shall see later, she has discovered a perfect hiding place for her egg. But mother beetle can hardly be aware of that. Having laid her egg, she seems to feel only the compulsion to get on with the rolling of the leaf as soon as possible. That she is now able to complete her task is due to the precaution she took in first cutting off the leaf supply of water and then in fracturing its veins. Without these precise instructions programmed into her nervous system as into a computer, the leaf would have become too stiff to roll. Now, however, it's as soft and pliable as linen. The control center of the beetle is its brain, a microscopic network of cells that coordinates its reflexes with the messages it receives from its sensory organs. But its ability to learn is extremely limited. In fact, it may know little more on the day it dies than on the day it was born. In all, about 2 hours have elapsed since she began to measure the leaf for rolling, and at last it is nearing completion. The role has become far larger than she is, but her powerful rangy legs, aided by her long hooked claws, keep everything securely under control. Mental touches, the tucking in of the flaps to make the roll self-sealing and virtually ravelproof. A truly monumental job of wrapping. Except for the cutting of the threads that still bind the leaf to the tree, her work is over. So once again, she climbs to the top of her cradle. This time to detach it. Under her legs, the huge leaf roll bobs and sways as her mandibles tear at the remaining fibers. But she doesn't let up till the last of them have been ripped away and the cradle falls to the ground. During her lifetime, this mother beetle will lay about 30 eggs, which for an insect is a very small number. And because this is such a small number, she builds a cradle for each. By contrast, insects that lay thousands of eggs leave them relatively unprotected and rely mainly on chance for the survival of their species. What is likely to happen to an egg that is left unprotected on the ground is shown in this simple experiment. In minutes, an ant finds it and carts it away. With millions of insects hungrily roaming every acre of ground, such a prize is not likely to go unnoticed for long. But how different is the fate of the egg inside the cradle. It is safe from siege and seizure alike. But protection from other animals is not the only function of the cradle. As we discover when we uncover the egg and leave it exposed to the sun within a week, the larvae up and dies. But if at the end of the same period of time we cut open a normal cradle, we find a healthy larvae inside. Everything about the cradle is a marvel of efficiency. For not only does it furnish the larvae with protection, it also seals in its body moisture and warmth and it provides it with food. The food of course is the leaf itself. And as the larvae feeds on it, it eats away the walls of its prison, preparing for the day when it will have to break out. But living in a small space has its problems. One of these is waste disposal. But the larvae has a solution for this, too. It picks up its own droppings and stacks them in the rear where there's less danger of infection or of spoiling the taste of the food. Meanwhile, inside the cradle, the larvae continues to grow, shedding its skin several times, then changing into a pupa, which is the intermediate stage in the metamorphosis of a beetle. A week later, a hole appears at the top, and in the darkness, the gleaming jet black head of the omeo is seen. It is the young but fully developed beetle chewing its way out of its prison. The omega has emerged just as the leaf has dried into a useless husk. A timing which, to say the least, is wonderful, though not any more so than everything else about the adaptive genius of this insect. As we can see from the shape of its head, it's a female, which means that she too will be a roller of lead. But she has no need to look over the old model. When her time comes to build cradles, she'll build them exactly like this, in exactly the same way, and without giving the matter of constructing it a single thought. The blueprints have already been implanted in her cells, wired into her nervous system. She is already a master builder of cradles like this by instinct. [Music]