Cicadidae

from A Treatise on Some of the Insects Injurious to Vegetation
by Thaddeus William Harris, M.D.
A New Edition, enlarged and improved, with additions from the author's manuscripts and original notes, illustrated by engravings drawn from nature under the supervision of Professor [Louis] Agassiz, edited by Charles L. Flint.
Crosby and Nichols, Boston, 1862.

Anatomy of the cicadas

The most remarkable insects in this group [the Homoptera] are those to which naturalists now apply the name cicada. They are readily distinguished by their broad heads, the large and very convex eyes on each side, and the three eyelets on the crown; by the transparent and veined wing-covers and wings; and by the elevation on the back of the thorax in the form of the letter X. The males have a peculiar organization, which enables them to emit an excessively loud buzzing kind of sound, which, in some species, may be heard at the distance of a mile; and the females are furnished with a curiously contrived piercer, for perforating the limbs of trees, in which they place their eggs. Without attempting a detailed description of the complicated mechanism of these parts, which could only be made intelligible by means of figures, I shall merely give a brief and general account of them, which may suffice for the present occasion. The musical instruments of the male consist of a pair of kettle-drums, one on each side of the body, and these, in the seventeen-year cicada (or locust, as it is generally but improperly called in America), are plainly to be seen just behind the wings. These drums are formed of convex pieces of parchment, gathered into numerous fine plaits, and, in the species above named, are lodged in cavities on the side of the body behind the thorax. They are not played upon with sticks, but by muscles or cords fastened to the inside of the drums. When these muscles contract and relex, which they do with great rapidity, the drum-heads are alternately tightened and loosened, recovery their natural convexity by their own elasticity. The effect of this rapid alternate tension and relaxation is the production of a rattling sound, like that caused by a succession of quick pressures upon a slightly convex and elastic piece of tin plate. Certain cavities within the body of the insect, which may be seen on raising two large valves beneath the belly, and which are separated from each other by thin partitions having the transparency and brilliancy of mica, or of thin and highly polished glass, tend to increase the vibrations of the sounds, and add greatly to their intensity. In most of our species of cicada the drums are not visible on the outside of the body, but are covered by convex triangular pieces on each side of the first ring behind the thorax, which must be cut away in order to expose them. On raising the large valves of the belly, however, there is seen, close to each side of the body, a little opening, like a pocket, in which the drum is lodged, and from which the the sound issues when the insect opens the valves. The hinder extremity of the body of the female is conical, and the underside has a longitudinal channel for the reception of the piercer, which is furthermore protected by four short grooved pieces fixed in the sides of the channel. The piercer itself consists of three parts in close contact with each other; namely, two outer ones grooved on the inside and enlarged at the tips, which are externally beset with small teeth like a saw, and a central, spear-pointed borer, which plays between the other two. Thus this instrument has the power and does the work both of an awl and of a double-edged saw, or rather of two key-hole saws cutting opposite to each other. No species of cicada possess the power of leaping. The legs are rather short, and the anterior thighs are armed beneath with two stout spines.  
Magicicada septendecim, drawn by Mr. Antoine Sonrel under the direction of
Prof. Louis Agassiz. Engraved on steel and colored by Mr. John H. Richard.
From Harris, 1862, new ed., op cit.
[Steeplate engraving] 

Lifecycle

The duration of life in winged insects is comparatively very short, seldom excedding two or three weeks in extent, and in many is limited to the same number of days or hours. To increase and multiply is their principle business in this period of existence, if not the only one, and the natural term of their life ends when this is accomplished. In their previous states, however, they often pass a much longer time, the length of which depends, in great measure, upon the nature and abundance of their food. ... The harvest-flies [cicadas] continue only a few weeks after their final transformation, and their only nourishment consists of vegetable juices, which they obtain by piercing the bark and leaves of plants with their beaks; and during this period they lay their eggs, and then perish. They are, however, amply compensated for the shortness of their life in the winged state by the length of their previous existence, during which they are wingless and grub-like in form, and live under ground, where they obtain their food only by much labor in perforating the soil among the roots of plants, the juices of which they imbibe by suction. To meet the difficulties of their situation and the precarious supply of their food, for which they have to grope in the dark in their subterranean retreats, a remarkable longevity is assigned to them; and one species has obtained the name of [Magicicada] septendecim, on account of its life being protracted to the period of seventeen years. 

Early reports in Massachusetts

This insect has been observed in the southeastern parts of Massachusetts, and in the valley of the Connecticut River, as far north at least as Hadley; but it does not seem to have extended to other parts of the state. The earliest account that we have of it is contained in Morton's "Memorial," wherein it is stated that "there was a numerous company of flies, which were like for bigness unto wasps or bumblebees," which appeared in Plymouth in the spring of 1633. "They came out of little holes in the ground ... and made such a constant yelling noise as made the woods ring of them, and ready to deafen the hearers."

Description of the Seventeen-Year Cicada

The seventeen-year cicada ([Magicicada septendecim (Linnaeus)]) in the winged state is of a black color, with transparent wings and wing-covers, the thick anterior edge and larger veins of which are orange-red, and near the tips of the latter there is a dusky zig-zag line in the form of the letter W; the eyes when living are almost red; the rings of the body are edged with dull orange; and the legs are of the same color. The wings expand from [64 to 83 mm]. 

Egg-laying

In those parts of Massachusetts which are subject to visitations of this cicada, it may be seen in forests of oak about the middle of June. Here such immense numbers are sometimes congregated, as to bend and even break down the limbs of the trees by their weight, and the woods resound with the din of their discordant drums from morning until evening. After pairing, the females proceed to prepare a nest for the reception of their eggs. They select, for this purpose, branches of a moderate size, which they clasp on both sides with their legs, and then, bending down the piercer at an angle of about 45 degrees, they repeatedly thrust it obliquely into the bark and wood in the dircetion of the fibers, at the same time putting in motion the lateral saws. and in this way detach little splinters of wood at one end, so as to form a kind of fibrous lid or cover to the perforation. The hole is bored obliquely to the pith, and is gradually enlarged by a repetition of the same operation, till a longitudinal fissure is formed of sufficient extent to receive from ten to twenty eggs. The side-pieces of the piercer serve as a groove to convey the eggs into the nest, where they are deposited in pairs, side by side, but separated from each other by a portion of woody fiber, and they are implanted into the limb somewhat obliquely, so that one end points upwards. When two eggs have been so placed, the insect withdraws the piercer for a moment, and then inserts it again and drops two more eggs in a line with the first, and repeats the operation till she has filled the fissure from one end to the other, upon which she removes to a little distance, and begins to make another nest to contain two more rows of eggs. She is about fifteen minutes in preparing a single nest and filling it with eggs; but it is not unusual for her to make fifteen or twenty fissures in the same limb; and one observer counted fifty nests extending along a line, each containing fifteen or twenty eggs in two rows, and all of them apparently the work of one insect. After one limb is thus sufficiently stocked, the cicada goes to another, and passes from limb to limb and from tree to tree, till her store, which consists of four or five hundred eggs, is exhausted. At length she becomes so weak by her incessant labors to provide for a succession of her kind, as to falter and fall in attempting to fly, and soon dies.

Results of egg-laying

Although the cicadas abound most upon the oak, they resort occasionally to other forest trees, and even to shrubs, when impelled by the necessity for depositing their eggs, and not infrequently commit them to fruit trees, when the latter are in the vicinity. Indeed there seem to be no trees or shrubs which are exempted from their attacks, except those of the pine and fir tribes, and of these even the white cedar is sometimes invaded by them. The punctured limbs languish and die soon after the eggs which are placed in them are hatched; they are broken by the winds or by their own weight, and either remain hanging by the bark alone, or fall with their withered foliage to the ground. In this way orchards have suffered severely in consequence of the injurious punctures of these insects.

Eggs

The eggs are [2 mm] long, and [1.6 mm] through the middle, but taper at each end to an obtuse point, and are of pearl-white color. The shell is so thin and delicate that the form of the included insect can be seen before the egg is hatched, which occurs, according to Dr. Potter, in fifty-two days after it is laid, but Miss Morris says forty-two days, and other persons say in fourteen days. 

Dramatic earthward plunge

The young insect when it bursts the shell is [1.6 mm] long, and is of a yellowish-white color, except the eyes and the claws of the forelegs, which are reddish; and it is covered with little hairs. In form it is somewhat grub-like, being longer in proportion than the parent insect, and is furnished with six legs, the first pair of which are very large, shaped almost like lobster-claws, and armed with strong spines beneath. On the shoulders are little prominences in the place of wings; and under the breast is a long beak for suction. These little creatures when liberated from the shell are very lively, and their movements are very nearly as quick as those of ants. After a few moments their instincts prompt them to get to the ground, but in order to reach it they do not descend the body of the tree, neither do they cast off themselves precipitately; but, running to the side of the limb, they deliberately loosen their hold, and fall to the earth. It seems, then, that they are not borne to the ground in the egg state by the limbs in which their nests are contained, but spontaneously make the perilous descent, immediately after they are hatched, without any clew, like that of the cankerworm, to carry them safely through the air and break the force of their fall. The instinct which impells them thus fearlessly to precipitate themselves from the trees, from heights of which they can have formed no conception, without any experience or knowledge of the result of their adventurous leap, is still more remarkable than that which carries the gosling to the water as soon as it is hatched. In those actions that are the result of foresight, of memory, or of experience, animals are controlled by their own reason, as in those to which they are led by the use of their ordinary senses, or by the indulgence of their common appetites, they may be said to be governed by the laws of their organization; but in such as arise from special and extraordinary instincts, we see the most striking proofs of that creative wisdom which has implanted in them an unerring guide, where reason, the senses, and the appetites would fail to direct them. The manner of the young cicadas' descent, so different from that of other insects, and seeming to require a special instinct to this end, would be considered incredible, perhaps, had it not been ascertained and repeatedly confirmed by persons who have witnessed the proceeding. On reaching the ground, the insects immediately bury themselves in the soil, burrowing by means of their broad and strong fore feet, which, like those of the mole, are admirably adapted for digging. In their descent into the earth they seem to follow the roots of plants, and are subsequently found attached to those which are most tender and succulent, perforating them with their beaks, and thus imbibing the vegetable juices which constitute their sole nourishment.

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