The Termites Are Winning

U.S. scientists last week admitted that one war is being lost-this year the 58 U.S. varieties of termites, frail, pale, 1/4-inch-long insects, will destroy some $50,000,000 worth of property (by boring into and eating the wooden framework of buildings), and almost nothing can stop them.

This equals the annual damage done by rats, mice or weevils, and exceeds that of tornadoes, earthquakes or arsonists.

It is also another way of saying that the power of the termite attack is greater than the power of the human defense. No important new anti-termite measures (present cost: some $7,000,000 a year) can be devised until man learns more about his insect enemy. Meanwhile the ingenious termites are also learning how to circumvent man.

The greatest single event in termite history was the invention of central heating. Better-heated houses now permit these sensitive insects to extend their activities for the first time into regions where temperatures under 50DEG would otherwise kill them. In general, human civilization has been a blessing to termites. In large areas of the South and West, termites have built themselves into the underpinning of the American home.

Only in the last 20 years have scientists really become termite-conscious. Termites were almost unknown in 1781, when the Royal Society decided that Naturalist Smeathman was heat-crazy when he reported that tropical termites build nests ten to 35 ft. high (sometimes miscalled ant-hills), the largest structures built by any animal except man. In the U.S. the work of termites was long mistaken for that of fungi and dry-rot which usually follow their riddlings.

Most U.S. termites eat deadwood. They have the almost unique power of digesting cellulose. Hence, unlike most animals, they have little natural competition to check their increase. Most insects depend upon a seasonal food supply, and their life cycles allow them only brief intervals to feed and breed. Termites almost never stop eating.

They live in and on wood. They build and bore for themselves airtight galleries which shut out light, diseases, most enemies. These galleries also keep their colonies humid and draftless, so that the soft-bodied insects do not dry up. This sheltered existence makes termites hard to fight. When soil-nesting termites travel to find wood, they construct long covered runways, which may reach even to the second floor of a house.

Mighty Gut. A termite digests cellulose with the help of the swarms of protozoa (one-celled animals) which teem in its guts. Since termites reduce cellulose (the toughest part of plants) to humus and provide food for new plants, their destruction of wood is really a vital part of the vegetative cycle of growth and decay.

Its unusual eating habits also keep the termite safe from poisoned bait (used against ants, grasshoppers, etc.), contact poisons (used against orchard pests, etc.), poisoning of breeding grounds (used against mosquitoes), dusting (used against the boll weevil), introduction of natural enemies (used against the Japanese beetle and boll weevil) and other routine methods of fighting insects.

Practical Socialism. The menace of termites is increased by their socialist tendencies-they are the most communal of insects. Some ants, wasps and bees are solitary; there are no solitary termites. They have three major castes: reproductives, workers and soldiers. With a male as well as a female reproductive in each colony, termites differ from all other social insects, which are matriarchic. They are the most fecund of all land animals. Some queens become enormously swollen with eggs, attaining a length of over five inches-20,000 times bigger than soldiers and workers. They produce as many as 7,000 eggs a day for incredible periods -sometimes as long as 40 years.

Chemical Warfare. Termite soldiers are so specialized for war that they cannot even feed themselves, must be crammed by workers. Their fantastic defense mechanism is designed solely for use against their chief enemy, ants. The soldiers' enlarged heads (see cut, p. 38) contain glands which produce a viscous chemical. Some times it is squirted forth in a gooey stream which entangles the attackers, and some times confuses and repels them by its odor.

These outsize military heads are also useful for 1) plugging breaches in nests and runways until the workers can repair them, 2) pounding loudly against the walls to warn other termites of danger-a sound often heard by exterminators.

Can Man Win? U.S. termite trouble may become worse. There is constant danger that new varieties will be imported (the U.S. has already exported several varieties of termites in lumber to Europe, where only two native types occur). But most scientists doubt that the termite and other social insects will conquer man and dominate the earth, despite the fears of Novelist H. G. Wells. Reason: limitations of their breathing apparatus.

In insects, as Naturalist Julian Huxley explains, microscopic air tubes carry oxygen "directly to and from the tissues instead of using dual mechanisms of lungs and blood stream. Laws of gaseous diffusion are such that [this system] is extremely efficient for very small animals, but becomes rapidly less efficient with increase of size, until it ceases to be of use at a bulk below that of a house mouse. [So] no insect has become moderately large by vertebrate standards or moderately intelligent." If the termite had a proper trachea, man might never have appeared on earth.

End of the Hunt

Ever since it was founded in 1869, Manhattan's great American Museum of Natural History has felt self-conscious about a gap in its collection of animal skeletons-the skull of the rare, nearly extinct Java rhinoceros, which has never been shown in any zoo on earth. Since 1920 the museum has sent many expeditions, financed by Trustee Arthur Vernay, to Malaya on fruitless searches for the shy beast.

But the museum has its rhino skull at last. It was found amid a heap of dusty bones in the Museum's attic, where it has lain since 1869.

Trustee Vernay had not yet been notified of the good news last week. Said a curator: "We're afraid to tell him."

Weed Makes Good

The pesky milkweed, cursed by farmers, has found a use-as a substitute for kapok. With a newly invented milkweed gin, a Michigan factory will next month start removing 1,000,000 lb. of floss from milkweed pods, for the U.S. Navy. The floss will replace kapok, formerly imported from Java, in l) life jackets where, like kapok, it is six times as buoyant as cork; 2) linings of flying suits, where it is as warm as wool but six times lighter. Next year farmers will be paid to plant free milkweed seed in 50,000 barren acres of upper Michigan.

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