The World Outside My Window Read online

  Amongst our more vocal and better-known insect musicians are those that dwell in trees, the cicadas and the crickets. As musicians, the cicadas are in a class by themselves. Most of the species in India are forest dwellers, but there are some who inhabit the open country in the plains. All through the hot weather their chorus rings through the jungle, while a shower of rain, far from damping their spirits, only rouses them to a deafening, combined effort. The ancient Greeks knew the cicada well. They appreciated his music so much that they kept him captive in a cage to sing. Only the males were chosen, for the females, like most insect musicians, were completely dumb. This moved one of the Greek poets to exclaim, ‘Happy are the cicadas, for they have voiceless wives.’

  The cicada’s sound-producing organs are amongst the most remarkable in the animal kingdom. The underside of his body carries a pair of flaps, each of which covers an oval membrane, which looks like the head of a drum. These are set into motion by a great pair of muscles attached to them from within the body, and the sound is produced by their vibration. The whole abdomen, which is practically hollow, helps to increase or diminish the sound.

  Simple, isn’t it? To be truthful, I find it extremely complicated, and am able to describe the process only by consulting the notes of S.H. Prater, one-time curator of the Bombay Natural History Society.

  Let it be added that the female carries these structures in a modified form, but as she has no muscles to bring them into play, she is unable to use them. This is why she must remain silent while her spouse shrieks away. I would change the line from that Greek poet (Xenarchos, I think) and say instead: ‘Pity the female cicadas, for they have singing husbands!’

  The object of the cicadas’ mirthful music is a mystery. It may attract the opposite sex, or it may be just a diversion of the male. Or perhaps he sings because he is happy.

  The tree crickets are a band of willing artists who commence their performance as soon as it is dusk. Their sounds are familiar, but the crickets are seldom seen. If one of them enters the house and treats us to a solo, the sound is so surprisingly loud that we can hardly believe it is being produced by so small a creature.

  The common Indian tree cricket is a delicate pale-green little creature with hazy, transparent green wings. In full song he holds his wings outspread over his back. They vibrate so rapidly that they are but a blurred outline. A tap on the bush or leaf on which he sits will put an immediate stop to his performance. His music ceases, and he lowers his wings and folds them flat on his back. The grasshopper makes his music by rubbing his legs against his forewing.

  I won’t go into detail over how the cricket produces its music, except to say that its louder notes are produced by a rapid vibration of the wings, the right wing usually working over the left, the edge of one acting on the file of the other to produce a shrill, long-sustained note.

  One of the best-known crickets is a large black fellow who lives underground and rarely comes out by day, except when the rains flood him out of his burrow. But when night falls, he sits on his doorstep and pours out his soul in a strident song. This cricket’s name is as impressive as his sound—Brachytrypes portentosus.

  The mole cricket is a genius by itself. Mole crickets are tillers of the soil. They use their powerful forelimbs for shovelling up the earth and their hard heads for butting into it. Notwithstanding its earthy occupations, the mole cricket is sometimes moved to creating music. But as he repeats his note, a solemn deep-toned chirp, about a hundred times a minute, the performance can be monotonous.

  In India, the cone-headed katydids are probably the most notable performers. Katydids are trim, slender grasshopper-like insects, much in evidence in the fresh green grass of the monsoon. In the fields the loud, shrill notes of the males may be heard both by day and by night. Sometimes one of them comes into a house and treats its occupants to a sudden outburst of high-pitched fiddling. His song rises in pitch as the performer warms to his work. In a room it can be quite deafening, and the sound is always difficult to locate—it seems to come from everywhere.

  Finally we come to the tree crickets, a band of willing artistes who commence their performance at dusk. Their sounds are familiar, but it is difficult to see the musicians. Presumably the males sing in order to attract their more silent females. The music advertises the presence of the male, just as in other creatures it is the colour or smell that does the job. And if music be the food of love, play on, cicada!

  Why are grasshoppers and crickets such persistent little singers? Do they really sing to charm and attract the females, or is their song the voice of mirth? A curious habit has been noticed among certain tree crickets, which may offer a clue to the mystery. Sometimes, as a male sings, a female steals up to him from behind. The male ceases his music. He sits quite still with his wings uplifted. The female noses about his back and soon discovers the object of her search—a deep cavity situated just behind the base of his wings. This cavity contains a clear liquid which she eagerly laps up. Well, even the human male seeks to please his sweetheart with the offer of chocolates.

  It is supposed that in this instance the lady is attracted rather by the sweets the male has to offer than by his music. But the music advertises his whereabouts. She hears his sound and knows that he has a sweet nectar to offer her and comes after it. If the artful luring of the male sometimes results in mating, we see the real reason for the male possessing his musical instruments, and understand his urge to play them so continuously. After all, the luring of the female with music and sweets is even practised by human beings. It may not always succeed in its purpose. Sometimes, as with the crickets, the female accepts the gifts so generously offered—and then takes her leave!

  Ants and Ant Lions

  Red ants may be small, but it is not difficult to find them because they will soon let you know of their presence by their fiery bite.

  This notorious (but quite useful) ant lives in trees and makes a nest of leaves, which it fastens together in a very clever manner. The adult ant possesses no material with which to fix up the leaves, but the immature ant-grub or ‘larva’ has glands that give out a sticky substance, and adult ants make use of this much as we use a gum-bottle. Several ants hold the leaves together whilst others, each seizing a grub and holding it between their forelegs, use it as a living gum-bottle to wet the edges of the leaves, which are then pressed together by the ants holding them.

  If you examine such a nest closely (not too closely!) you will find that it is humming with red-ant life. This little ant is a terrific feeder, and will carry away almost any scrap of refuse that he finds. He guards his nest very carefully, and any intruder is attacked by a number of worker-ants, each inflicting a very painful sting. The red ant is useful to man because it lives on insect parasites in fields as well as in godowns. It collects and destroys termites (or ‘white ants,’ which eat through everything from oak cupboards to Persian carpets) and bedbugs. Some people, of course, might prefer having bugs rather than red ants in their beds!

  Incidentally, in Kanara and some other parts of South India, and throughout Burma and Thailand, a paste is made of the red ant, which is eaten as a condiment with curry.

  Some of you may have noticed lines of black ants walking up the stem of a tree or plant whilst others are descending—all of them equally in a great hurry. They are after the tiny green, black or brown insects, the blights or aphis, which feed on the sweet sugary sap of the plant, drawing it in through the mouth and passing it out at the other end of the body. They spend their lives doing this.

  Ants are very fond of sugar (you must have found them in your sugar bowl often enough), and an ant will make use of a blight in much the same way that a small boy will make use of a stick of sugarcane. The blight has two little tubes passing through the body, and if the insect is pressed from outside a little sugary liquid exudes from the tubes. The clever ant knows this, and with his feelers he drums on the back of the insect, causing the sugary liquid to rise and overflow from the tubes. This is s
ucked up by the ant until the blight or aphis runs temporarily dry.

  The process is similar to our own method of milking a cow. Some communities of ants keep certain kinds of blights in their nests, using them in the same way that we use cows and goats.

  Ants are hard-working, serious-minded little fellows, and you will never find them wasting their time. They will store up grain against hard times in the winter, taking it into their nests or heaping it into piles outside the entrance.

  The ant has a deadly enemy in the ant lion, a small insect with a very strong pair of jaws. Many small insects have met their death by falling into the cleverly built traps made by ant lions.

  The ant lion is only half-an-inch long. Its short, squat body is a dirty grey colour that makes it almost invisible in the sand where it lives. As soon as it hatches from the egg, it starts looking for a place to build its trap.

  A sheltered spot is ideal, so that the sand will not be dampened by rain or blown away by the wind. When the ant lion has selected a site, it begins to scoop out a small circular pit in the sand. It uses the end of its body like a small plough, and tosses the sand outside with a jerk of its flat head. When it has finished digging its funnel-shaped pit, it buries itself in the sand at the bottom and lies in wait for some unwary insect. It will wait quietly for hours or even days, its two hollow, curved jaws the only things sticking up out of the sand.

  Once a small insect is caught by these powerful jaws, there is little hope of escape, for the ant lion quickly drains away the fluids from the insect and throws the empty skeleton out of the pit. Then it retreats into the sand to wait for its next victim.

  Eventually, the ant lion weaves a small ball of silk about itself and changes into a graceful winged adult that looks something like a small dragonfly.

  Walk Tall

  You stride through the long grass

  Pressing on over fallen pine needles,

  Up the winding road to the mountain pass:

  Small red ant, now crossing a sea

  Of raindrops; your destiny

  To carry home that single, slender

  Cosmos seed,

  Waving it like a banner in the sun.

  Scorpions

  Scorpions are creatures with an evil reputation, and deaths from scorpion stings do sometimes occur in India; but in most cases the victims have been either children or women in weak health condition. Scorpions may live under stones or fallen tree trunks, in deep burrows dug in the soil or in shallow holes in sand, and sometimes in shoes or slippers. There are over 350 different species of scorpions in the world, and India provides a home for at least eighty of them.

  One of our best-known species is the common red scorpion, found in the dry regions of Punjab and throughout northern, central and southern India, except in the extreme south. It has a reddish-brown body, yellowish legs and a robust yellow tail with sting attached.

  Another common species is the rock scorpion, one of the largest in the world, a black and hairy beast which grows to a length of about eight inches. It walks with its belly touching the ground, and usually drags its great tail behind it. The red scorpion, on the other hand, raises its body high on its legs and curls its tail over its back. In its swifter movements the tail is trailed behind.

  Scorpions feed mainly on insects. How such an agile, wary creature as the cockroach allows itself to be caught by the slow-moving, short-sighted scorpion is a marvel. But the life of a cockroach, when it encounters a scorpion, is brief. It either panics and stumbles over the crouching scorpion, or starts inspecting it with its long feelers. The scorpion’s pincered arms reach out, and the cockroach is firmly in their grip. Over comes the deadly tail, and the victim is stabbed to death.

  A large insect, like a cockroach, is not killed immediately; but the venom paralyses its muscles and leaves it helpless. A reckless stab against the horny covering of an insect like the beetle might easily break the point of the scorpion’s sting. That is why the tail is usually carried up or raised from the ground, to keep the sting from being damaged.

  Not much is known about the private habits of scorpions, but the great French naturalist, Jean Henri Fabre, established a colony of scorpions in his garden, observed them closely and gave a fascinating account of their courtship and mating habits.

  After circling round each other, the male and female stood face-to-face with raised tails. These they intertwined in a friendly embrace. This was followed by a solemn dance. The couple held hands: the male seized the pincers of the female in his own, walking backwards, while she followed him modestly. Backwards and forwards they continued for about an hour, until at length the male began to dig a hole, but without leaving his hold of the female. A home prepared, he dragged her ‘over the threshold’.

  His mastery over his spouse is only limited to the period of courtship. The male scorpion is often seized and eaten by the female soon after mating: a custom that is also popular with spiders, but not, as yet, amongst humans.

  The Spider in Her Parlour

  Where do the flies go in the cold weather? There are various opinions. Some entomologists think that they hibernate in warm corners, others hold that the adult flies all die and only the larvae survive into the following spring. Whatever the truth may be, it is known that just one pair of houseflies could, in a single summer, become the ancestors of the staggering total of 191 million million million more of their objectionable kind! Fortunately, only a small proportion of their descendants survive, the rest surrendering to famine, disease and their natural enemies—our friends—the spiders.

  A spider’s web can be relied upon to catch flies as efficiently as the best flypaper. But ants, bees and wasps, who have a memory and use it, are not usually trapped. Flies belong to a lower order and have no memory and the fact that a fly has struggled free, escaping very narrowly with its life, will not prevent that same fly from getting caught again soon after. Ants, on the other hand, will go to great trouble to rescue a nest-companion, and have even been known to bring fine sand and scatter it across flypaper to make a path to their companion in distress.

  Any insect caught in a spider’s web stands very little chance of escape, because the sticky web holds it captive until the owner returns. Then she (we will assume it is a female spider since the males though quite plentiful, are small, weak by comparison and less likely to be seen) spins more and more silk over her victim until it cannot even move, when she stings the helpless creature to death with her fangs.

  All spiders have fangs; they are therefore held in great respect by most members of the insect world (to which they do not belong, having eight legs) since their bite to them is deadly. Towards humans, of course, the spider has no harmful intent, and there are only a few rare kinds which are poisonous.

  One of the most dangerous is the bird-eating spider, found in the West Indies and tropical South America. Being arboreal, it is often found in a banana tree, where it constructs a thick untidy web. Its normal prey consists of large insects, although it welcomes small mammals and birds if they become entangled. As large as a saucer when full-grown, the bird-eating spider moves quickly and inflicts a vicious and poisonous bite, which is sometimes fatal to humans.

  However, to return to our more common and harmless house spiders, they are shy creatures and come out mainly at night—which is why we see so few of them, though their numbers are vast. They are carnivorous or meat-eating animals and will tackle almost anything, provided it is alive—even each other. Indeed, the courtship of his mate is a very risky thing to the male spider who, if he escapes intact, is lucky. Baby spiders can be seen scurrying away from their mother as fast as their legs will take them, and those which hatch after they are born soon learn to keep their distance from each other. For this reason, attempts to produce spider-silk commercially have failed. Unlike the familiar silkworm, they simply cannot be persuaded to live sufficiently close together.

  As I have said, spiders are not insects: they have two legs too many, their head and thorax is
complete in one (no join at the neck) and they never have wings. Even so, some spiders can fly. They climb to the top of a high post and send out long lines of silk which, when caught by the wind, act as kites. The little creatures cast themselves off when the tug is just right and can fly in this way for many miles and at great heights. They have been found by research aeroplanes at altitudes of 5,000 feet—nearly a mile in the air!

  Nor are these the only purposes to which the spider puts her silk. One American spider chooses a good position, such as the end of a branch, and spins out a long line, which she weights with a ball of the same stuff. She then flings this at any tiny insect flying her way and hauls in her catch. She never sticks to it herself, because of a special oil her body makes to protect her.

  Insects in Disguise

  Curious as the mantis or praying insects are, their present appearance has probably come about through a continuous series of minute changes that enable them to obtain their prey (which consists chiefly of other insects) with greater ease. They are heavy and clumsy on the wing, and sometimes they are wingless. These insects have discovered that by imitating the colour and characteristics of their surroundings, they have a better chance of capturing their prey.

  The foliage-dwelling mantises have acquired a vivid tint of green, with perhaps yellowish and brownish markings, which enable them to lie unnoticed on a leaf or green twig till some unwary insect comes their way; and there are other, banded or spotted species, which are usually found amongst flowers.

  Have you ever watched a mantis hunting? Only the two hind pairs of legs are used for walking. On them he heaves over very slowly so that the movement is scarcely noticeable; and then, just as his centre of gravity is almost lost, out shoots a leg with amazing swiftness. Another gradual heaving over of the body, and another lightning movement of the leg. And so he advances step by step until the prey is within reaching distance of the mantis’s terrible forelegs. There is no escape from those forelegs once they close round a lesser insect.