Pick from the Past
Natural History Magazine, September 1941
The Truth About Termites
|A curious thing is that, although termites feed on wood, some of the species cannot digest it but depend upon Protozoa living in their intestinal tracts for that important step in the process of changing dead wood into living termites.|
Some species of termites live chiefly or wholly in wood; others chiefly in the ground; and others, like our Reticulitermes flavipes, must have both earth and wood for their dwelling. Dead wood is the favorite food of most termites and, so, those that live partly or wholly in wood quite efficiently carve out their dwellings by feeding on themthey both eat their cake and have it. Since flavipes must have an earthen cellar to its house, stumps or fence posts or timber lying on the ground quite suit it; but it never damages buildings in which the lowest timbers are on sufficiently high solid concrete foundations.
A curious thing is that, although termites feed on wood, some of the species cannot digest it but depend upon Protozoa living in their intestinal tracts for that important step in the process of changing dead wood into living termites.
Some biologists are given to dating the occurrence of one natural phenomenon by reference to another, instead of solely to a man-made calendar, Gregorian or otherwise. This plan is at least rather pleasing, whatever its scientific advantages or disadvantages may be. Thus, Snyder, in telling about the maturing and flight of young termite queens near Washington, D.C., refers to the blooming of flowering dogwood, which has, of course, no direct connection with termite queens but occurs at the same time as their spring flight. He says that when the flower buds of the dogwood were swelling the young queen termites were about ready to undergo the molt that gives them their wings; when the first few flowers had opened, a few recently molted adults were in the termite nests, when the blossoms were half out the winged adults in most colonies had attained mature pigmentation; and by April 30 the adults had swarmed from colonies. Dogwood was nearly in full bloom. Fine!
I have started several times to keep records in this manner. It is an excellent drill in all-around natural history, and I highly recommend it to others but suggest that references to a man-made calendar by jotted down on the side.
The swarming of our real ants is a nuptial flight, hundreds, sometimes thousands, of males and virgin females darting about in a dizzy dance from which newly mated pairs drop out, the female to begin her humdrum existence in the darkness of some burrow and the male to die. Virgin honey bees have a nuptial flight but it is rarely noticed, a single female going forth without any rivals and returning entirely alone, she, too, leaving her groom to die. The bride among honey bees comes back to the home in which she was born. (What we call a swarm of honey bees is really a colonizing and not a mating flight. It is the mother and spinster daughters vacating in favor of a bride-to-be.)
The swarming of our termites is different from either of these. Males and many virgin females fly out together. There is more or less courtship during the flight but no actual mating then. Soon the females settle to the ground and shed their wings, the flight being over. If a female has been at all attractive, at least one male is with her and, after the wings have been shed, courtship becomes more energetic. Matters are finally arranged and the happy pair starts housekeeping, the male living to enjoy home-life. Female sluggards, if such there be, among humans may consider the ways of real ants and be wise, but most men would doubtless prefer the ways of the so-called white ants, the blondes.
The family life of termites is extremely complicated. I shall not attempt to explain it to you in detail, largely because I do not understand it myself. Incidentally, no one else understands it fully.
The original queen of a colony of some tropical species becomes an excessively swollen egg-producing machine, her abdomen so large that she cannot drag herself about but lies in a special royal cell, accompanied by one or more mates, the kings, and attended by a horde of workers who feed her and carry away the eggs that she lays.
|Among ants, bees, and wasps the workers and soldier-workers, if any, are all females; but among termites either sex may apparently become either sort, depending on we know not what.|
I like our flavipes better. Its queen goes about from one part of the nest to another. Like many other species, flavipes has two forms of individuals other than those whose primary function is reproduction. There are ordinary workers and also workers with, among other differences, large jaws. The ones with big jaws are called soldiers. Snyder says: The duty of the soldiers is apparently entirely protective, but they do not appear to be very effective, at least when the colony is opened and they are exposed to the attacks of ants, etc. So, there another good story goes bang! But, if not for protection, what are they for? Ornament? Possibly. Who knows? It costs much food to rear and maintain them but the same is true of human soldiers. Among ants, bees, and wasps the workers and soldier-workers, if any, are all females; but among termites either sex may apparently become either sort, depending on we know not what.
These things are complicated enough to suit the most energetic of puzzle-solvers but, as though to make it more difficult, there are three different sorts of reproductive individuals: first form, second form, and third form. These are not very entrancing names but they are sufficient. Then there may be various kinds of intermediates, and so on. What are they all and why? If not why, at least how do they come to be?
It seems that, in some species at least, if the original queen, a first-form reproductive, dies, one or more of the second-form reproductives take up the work of laying eggs and, if all the second-form reproductives die, then one or more of the third-form reproductives do the egg-laying. But, as long as there is a living first-form, neither second-forms nor third-forms functionabundantly, at leastand as long as there is a living second-form reproductive, none of the third-forms function. Furthermore, although a first-form can be the parent of all three forms, a second-form cannot produce a first-form (but can produce second-forms and third-forms, and a third-form can produce neither first-form or second-form but can produce third-form reproductives.
Until more has been learned about this matter, it is perhaps just as well not to suggest explanations here. If things are as I have stated them, such a termite colony is, barring a major calamity such as running out of food, a perpetual affair. It may easily lose its original first-form reproductives, but the others can carry on.
I wish long life to the person who would learn all that there is to be known about the Reticulitermes flavipes that came to our yard in a fire log. Perhaps a study of that colony at the Presbyterian Hole would have revealed some of the things that were planned to be taught there when the hole was dug. But it is now too late. The property has been sold again, and the hole has been made a sunken garden full of things that are pretty but not particularly interesting because they are so artificial.
I have said, It was formerly a surprise to many that termites may naturally occur in a New York City suburban yard. Popular opinion on that subject was changed by one of the most outrageous campaigns of false advertising and high-pressure salesmanship that has ever come to my attention in entomology. People who trusted newspapers, slick talkers, and writers of catchy letters for their ideas about insects were persuaded that their region had been suddenly invaded by termites; that not a house was safe from the attack of this horrible horde; that something must be done at once or the houses would come crashing down on the human inhabitants; that such-and-such a company could do this something at a cost that was high but not equal to the cost of the house, and that the company would guarantee on its bond that the house would then be safe for a specified term of years.
The facts are as follows:
There has been no invasion of termites. The species that is here now was here before Europeans, whatever their nationality may have been, first sighted American shores. Indeed, the same kind of termite was probably here long before there were human beings.
There has been no marked increase in the numbers of this insect except in the minds of the people who have recently been made termite-conscious by propaganda. Unless I am greatly mistaken there are fewer termites in and near New York City than there were more than 30 years ago when I first moved here. One very good reason for this is the sort of thing that happened in the Presbyterian Hole when it became a sunken garden. The present owner does not permit pieces of wood to lie on the ground and there are no stumps on his property. The same thing has been happening all through this region.
Any house is entirely safe from this or any other of our ground-nesting termites unless the woodwork of the house enters or comes nears the ground. (Steps are often offenders.) Of course, if you make of your house an artificial stump, termites may and probably sooner or later will make use of your thoughtless kindness to them.
|Even if your house is not correctly built and termites do get in, the house is not doomed. I have been told that Washingtons home at Mount Vernon has had termites in its timbers as long as anyone now living knows.|
Even if your house is not correctly built and termites do get in, the house is not doomed. I have been told that Washingtons home at Mount Vernon has had termites in its timbers as long as anyone now living knows. If that be true, they quite possible moved in shortly after Washington did. In my boyhood days in Pennsylvania it was the usual thing for the country houses and barns to have termites in the timbers. Not knowing that the trouble was due to the wood touching the ground, the people merely from time to time replaced the affected pieces with new ones and, not being bamboozled by purposeful exaggerations of scare-mongers, they took their time about doing it.
Such being the facts, there is no need to discuss here any further the methods of prevention or cure. Some of the methods used by some exterminators are absolutely worthless or even worse; and some of the exterminators do not know termites when they see them, as is witnessed by the variety of insects that they have thought were termites when they werent. Unfortunately, also, not even all entomologists who do know a termite when they see it are above sharp business practices. As for guarantees, anyone who can get a sufficient number of good houses to insure against termite damage at even small premiums could get rich by doing nothing more, because the chances are that most of the houses will never become infested and that the few that do will not be seriously damaged.
In this, as in all other insect-control problems concerning which you are in doubt, write to your State Entomologist and to the Bureau of Entomology of the U.S. Department of Agriculture. Your taxes pay for their services whether you make use of them or not; presumably they know their job; and their advice is not likely to be tinged with ulterior motives. All of this is not to say that there are not many intelligent men, good entomologists, some working as exterminators, making an honest living by controlling insect pests for those people who do not know how or who do not care to take the trouble of doing it themselves. Also, it is not to say that some day one of the dry-wood termites from some other place may not find its way to your region. If it does, the official state and federal entomologists should be told about it very quickly. Quite probably it would not become permanently established here; but, if it does, there may then be real trouble.
Darwin quite properly pointed out the service that earthworms do in turning over the ground and getting humus into it. But there are thousands of kinds of ground-burrowing insects; and, furthermore, there are thousands of kinds of wood-boring insects that are largely instrumental in clearing away dead and dying trees that would otherwise so clog the forests that there could be no new growth.
It is interesting to note that termites are among those insects that Nature uses to clear away stumps and fallen timber. In doing this they are very beneficial to the earth. If Man, in building houses, puts lumber, which is nothing but dead wood, in or on the ground, the termites quite naturally are apt to start clearing away that dead wood, too. Mans wooden houses and even Man himself are things of the last few days or so as compared with the geologic history of termites. If Man keeps the wood of his houses in this region sufficiently high above the ground, our termites will not bother him.