Insect guide > Termites

Termites


Termites(Order Isoptera.)
The Isoptera undergo practically no transformation, that is to say, they have very incomplete metamorphoses. The young termite, when it hatches from the egg is an active, crawling, sixlegged creature. It much resembles the adult, except in size, whereas with the ants, it will be remembered, the larva is a footless grub which looks no more like an adult than a garter snake resembles a chipmunk. All species, as just stated, are social and the communities consist of both wingless and winged individuals.

The four wings are very long and when in repose are laid flat along the back, extending far beyond the tip of the abdomen. They are membranous and most of the veins are longitudinal. The hind wings are of almost precisely the same shape and size as the front wings, and across near the base of each wing is a line of weakness along which the wing breaks off after the so-called nuptial flight. The wingless individuals in each colony are, with most species, excessively numerous and as a rule they are divided into two castes, namely, the ordinary workers and the soldiers.

The so-called soldiers also exist with the true ants but they have not in these creatures become such a structurally well differentiated caste as with the termites. In the latter the jaws have become enormously developed and in some cases the soldier is five times the size of a worker. Then, in some species a certain portion of the workers have become changed in form particularly by the elongation of the head into a long, nose-like process at the tip of which is a hole through which is exuded a fluid which is used in making or mending the wails of the habitation. This caste is known as the nasuti, or nosed ones, a term which must at once remind the admirers of Sienkiewicz of the Polish warrior, Kharlamp.

The order Isoptera reaches its highest development in tropical regions, and the reading world has been familiar with the main
details of the economy of the extraordinary species which build the great ant-mounds in Africa since the days when Smeathman the English traveler, described them in print more than a hundred years ago. The females, or queens, of some of these African species grow to be of enormous size. The abdomens swollen with eggs, sometimes becomes as big as a potato, or 20,000 or 30,000 times the bulk of a worker. The rate at which the eggs are laid is extraordinary and it is stated at sixty a minute, or 80,000 and upwards in a day.

In the United States there exist comparatively few species, and only one which has a northward range into the territory occupied by most of the readers. This is Termes flavipes Koll. It is probably a true American species but was accidentally introduced into Europe many years ago. It destroyed the imperial greenhouses at Schoenbron, near Vienna, so that they were replaced by houses with iron frames. Another species which is widely distributed in the United States, but
which does not seem to be especially common, is also found in Europe and is one of the most abundant and destructive termites found there. This is Termes lucifugus Rossi. It occurs in all of the Mediterranean countries in Europe and is found in Texas, Kansas, Colorado and Southern California, and perhaps elsewhere.

Another species, known as Termes tubiformans Buckley, is a form of curious habits occurring in Texas, in the spring, beneath and within patches of cow-dung, and after midsummer making tubes around grass stems and the stems of other plants, nesting probably deep in the ground. Still another Texas form, known as Eutermes nigriceps Haldeman, is a small species which constructs nests, apparently of cow dung, which are attached to the trunks of trees. Buckley wrote of this form, " It was about sunset on the 22d of October, when I first saw this species in a field, where both workers and nasuti were carrying home seeds of grasses and weeds. They marched in dense columns along pathways leading to a hole near the base of a stump, into which they entered. * * * They dwell in the ground where they have rooms, seldom more than one to two inches long, connected by tunnels. * * * After rains - which are of rare occurrence in that climate-they make semi-cylindrical tubes, which lie on the ground with a length of from three to six inches. These arched ways sometimes intercept each other, being connected with clambers ; but they rarely work by day above the surface and never in bright sunshine".

Of the commonest of our species, Termes flavipes, as far as we know, no thoroughly good account of its life history has been published. The true queen, in fact, has never been found, unless it should turn out that a large queen found in the mountains in southern Arizona should belong to this species.

In the Northern States its nests are to be found under almost any decaying log, and, although many entomologists have examined these nests, they have never found the queen. From Baltimore southward, and perhaps even a little farther north, this insect becomes a serious pest in houses, particularly in old houses which are rather damp. They make their nests in old beams, such as the main floor joists, and construct innumerable tunnels, running usually with the grain, so that, although a great deal of the substance of the wood is devoured, the main longitudinal fibers support the building structure for a long time ; in fact, their presence in many cases would not be noticed except for the spring flight of the winged males and females.

Quite recently a handsome private residence in the city of Baltimore was found to have its timbers on the first floor reduced almost to shells by the workers of this insect. Further south, not only the buildings, but even furniture is destroyed by them in the same way. They seem especially fond of paper, and it has been recorded the fact that a collection of books and papers in the state of Illinois was completely ruined by them. A school library in South Carolina, which had been left closed for the summer, was found, on being opened in the autumn to be completely eaten out and rendered valueless.

The work of these insects was brought home strongly to the writer on one occasion when a lot of records and documents stored in a vault in the Department of Agriculture was found to be mined and ruined by them ; and again, the floor of one of the largest sections of a museum was annually undermined and weakened until it was torn up and replaced with cement. Whenever an old beam is found to have been hollowed out, even if no insects are present, it can readily be identified as the work of termites by the fact that all of the galleries are plastered with a brownish, mortar-like substance composed of excrement, from which, apparently, all nourishing food has been taken. In Florida this insect is often the cause of great damage to orange trees, working around the crown and in the roots of trees, and altogether it is a thoroughly bad character. Read more about termite control at termite pest control.

In the most general terms the life of a termite colony is about as follows : After the so-called nuptial flight (which is made usually at a certain time of the year, and with Termes flavipes it is generally in the spring) composed of winged individuals of both sexes, male and female, and which always, except when it occurs in houses, attracts birds and other insect-eating creatures so that most of the individuals are destroyed, the wings of the survivors break off and they either pair and attempt to start a new colony or they drop in such a situation that workers from
some old colony find them, join forces with them, and thus start a new community.

The body of the true female, or queen, begins to swell with eggs, grows enormously, and egg-laying commences. Unlike the true ants or any of the other social Hymenoptera, the young require very little care from the workers. They are quite active and very soon feed themselves to some extent. The food of the termites is variable. It consists of wood fiber, or their own cast skins, or their excrement, or the contents of the stomach regurgitated by other individuals, or, in the case of the soldiers, they may eat dying or even healthy workers. The enlarged head and great jaws of the soldiers unfit them, in fact, for any other kind of food. They can not gnaw wood very well, and, as Sharp has expressed it, "their condition
may be considered to be that of permanent hunger, only to be allayed by carnivorous proceedings." When the nest is disturbed
and the soldiers get excited they dash their jaws around and frequently kill their fellows, but of course this is more or less accidental, since they have no eyes.

When a Callotermes wishes food, according to Grassi, it strokes the posterior part of the body of another individual with its antennae and by some sort of a reflex action the contents of the alimentary canal of the individual stroked issue from the anus and are devoured by the stroker. The habitations of all termites are very cleanly, which is accounted for by the fact that they eat everything, the contents of the alimentary canal being eaten again and again until all nourishment has been taken out of it. Hubbard, in Jamaica, found that the young feed upon prepared food which is stored up in the form of very hard and tough round masses, some nests containing many pounds' weight. This material is softened by saliva before it can be eaten.

The true queens can be distinguished at once by the stumps of their old wings as well as, later, by their enlarged abdomens; but there are in most colonies individuals known as supplementary queens, which are capable of reproduction up to a certain point and undoubtedly help to carry the colony on in case of the death of the true queen. These supplementary queens are undoubtedly female workers which have been fed in a certain way and which develop up to a certain point, although not to the point of becoming winged.

In America Termes lucifugus has not been studied that much, but in Europe its history is rather well known. It burrows in wood of different kinds, makes excavations and builds galleries so that it can move from one point to another without being exposed. This suggests that we have as yet omitted to state that all termites shun the light, except during the nuptial flight; in fact, the workers and soldiers are almost invariably blind, although with certain African species of the genus Hodotermes facetted eyes occur in these castes and they issue from holes in the ground during the heat of the day and cut grass. There seems to be some question, however, whether these creatures really belong to this group. It is supposed also that these galleries keep the right degree of moisture, since in dry air these creatures die.

Many thousands compose a community. The period of development apparently occupies from eighteen to twenty-three months. Probably in the whole range of insects treated on this site there is no species which offers a better and more convenient field of study than the common Termes flavipes. I feel sure that what we know about it is but a small fraction of what remains to be learned, and it is everywhere so abundant that the earnest observer need never be without material.

Just as with the ants, and also with some of the social bees, so that we may, in fact, say just as with all social insects, in the habitations of termites will be found many guest insects. Such insects in ants' nests are known as Myrmecophilous; in termites' nests they are known as Termitophilous insects, and the study of these insects, in the United States, offers an relative unexplored field. Mr. E. A. Schwarz has paid some attention to them, and in the Proceedings of the Entomological Society of Washington (Vol. 1, pp. 160, 161) has given a list of nine species of beetles found living in termites' nests and has published some very interesting notes about them. No true hymenopterous parasites of termites are known, unless the curious, big-headed chalcis flies of the genus Caratomus should prove to be parasitic upon them.

The damage done by termites in tropical regions is very great. In Central America it seems almost impossible to erect wooden poles which will last for any length of time, since they are tunneled by these creatures and weakened to their fall in an incredibly short time. Accounts of damage done in houses, both in Tropical America and in Africa, as well as in India, occur commonly in literature.

There are certain insects which belong to the family Embiidae which seem to have a relationship to the termites but their detailed consideration may well be omitted from this work, since but a single species is known in North America, namely, Oligotoma hubbardi Hagen, and which occurs rarely in Florida.