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Show INSECT MUSICIANS fSi"1! 7 NSECTS are a silent people fA in the main. Many of them oj'-cj pass through life without &s?- uttering a single sound But there are some interest-l&gp1" interest-l&gp1" ing exceptions to this rule. 0?' Tue harvest flies, or cica- t das, for example, are noto- Qiai&ti. riously noisy, the "song" of some species having been compared to the shrill whistle of a locomotive lo-comotive engine. They are very abundant in the warmer regions of both hemispheres. The males alone are tuneful a fact which was commented com-mented upon by certain of the Greek poets and philosophers, one of whom writes: "Happy the cicadas live, since they all have voiceless wives." Strictly speaking, however, the cicada ci-cada is not a vocalist, but an instru mentalist. The sounds that it makes are due to a special mechanism mecha-nism which resembles resem-bles a pair of kettledrums. ket-tledrums. These have their place in cavities on each side of the thorax, and are protected beneath by large plates which may possibly act also as soundingboards. The membranes of the drums are not beaten, but are thrown into rapid vibration by a special spe-cial set of voluntary volun-tary muscles, the result being the W MIR OF CCAOAS JECft FROM BftOli ( V N i ( 1 AYOUICCRASWPPSJl, fr. wewW3 sru if i i j f f L XUDIIFftrARY f 1M n J $1 - which the cicada yyJtf " Jfi cicadas, the only lztf I i X.W riflc insects are Yfi S tJf which naturalists 0 CX 'VJT 1 orthoptera" i. e. V 'skM Cv'XM Tickets and tlfeir ffMxA ances the analogy ff'ay1' be discarded for x's Wf Let us take first N-M& Everyone has lis- "&Cf!sS III ping, and perhaps " its have observed rORF-WmOF TflfComOfl FJFLD ways accompanied CRJCKFT (MALt) 3FM FRO1 Ul OMR ng of the insect's JiftTH. GRFftTL Y FRLARGFD,. loufl, shrill music for which the cicada is famous. Apart from the cicadas, the only other notably sonoriflc insects are found in the group which naturalists term the "leaping orthoptera" i. e. the grasshoppers, crickets and tlfeir allies. In these instances the analogy of the drum must be discarded for that of the fiddle. Let us take first the grasshoppers. Everyone has listened lis-tened to their chirping, and perhaps some inquiring spirits have observed that the sound is always accompanied by a kind of swaying of the insect's body, and an alternate movement of its hind legs. But the full inwardness of the matter can only be appreciated by the aid of the microscope. On a certain cer-tain ridge on the inner side of the grasshopper's hind femur the thigh of the great leaping leg there is a row of extremely modified hairs. This ridge represents the bow of the sound-producing sound-producing apparatus. By the movement move-ment of the leg it is rubbed to and fro against a prominent nervure or "vein" of the closed fore-wing; and this fiddling process gives rise to the grasshopper's well-known "song." "Stridulatlon." Naturalists call the method "stridu-lation." "stridu-lation." In the case of the crickets it Is managed in a different way, viz. by" rubbing one wing over the other. Each fore-wing of the male is furnished fur-nished with a vein which is minutely ridged or filelike on its under side; and this bow plays upon a vein on the upper surface of the wing beneath it. As the apparatus is in duplicate each wing having its vein and bow the insect is ambidextrous, so to speak. In practice, however, it is found that the right wing is generally, though not always, uppermost. The reverse is true of the long-horn, tree-frequenting tree-frequenting grasshoppers. Their soli tary filelike bow is found on the underside of the left fore-wing, which is always uppermost. In these insects in-sects and in the crickets to a lesser extent the overlapping fore-wings form a kind of resounding chamber which intensifies the volume of each note that the fiddler produces. Time and Temperament. Dr. S. H. Scudder, an eminent observer ob-server of insect life in America, has expressed some of the songs of crickets crick-ets and grasshoppers in musical notation. nota-tion. He has also recorded the curious curi-ous fact that there is a distinct relation rela-tion between the rapidity of note production pro-duction and the temperature. On warm days, when the sun is shining brightly, these little musicians !'ddle away with all their might, whereas in dull and chilly weather their execution Is slow and mournful. Many crickets, however, remain silent untli the shades of evening begin to fall, and then begin loudly to serenade their lady-loves. For this is really the outcome out-come of the whole matter. Only in rare instances do female insects possess pos-sess tho gift of melodious expression. As with the singing of birds, so with the drumming and fiddling of insects, each is essentially the language of courtship. Love makes the world go round! Crickets have been observed to listen eagerly one might say, critically crit-ically to the performances of their wooers, as if anxious to get the full m ml V) ' ",V '' "I A PAIR OF CICADAS JFFlY FROM 0FLOM benefit of every note produced. But how does an insect "listen?" In most insects the auditory organs if they can be demonstrated at all. take the form of excessively minute structures connected with nerve3 These structures, which are microscopic micro-scopic hairs, and cavities, are found most commonly upon antennae, but they may also occur upon other parts of the body. So far as the writer is aware, the cicadas have not been shown to possess pos-sess any specialized "ears." We are thus left to assume that they gain their impressions of sound by means of scattered sense organs such as those which have just beei. mentioned. men-tioned. Indeed, some authorities are of opinion that cicadas do not hearat all in our sense of the word, but that they "feel" rhythmical vibrations. Insects With Ears. With grasshoppers and crickets, however, the case is quite different. These insects undoubtedly possess fsm i 4r -SSL. m f Ax) art o rmARca wrt-ifc or a lcwc- HORIY GRA55HOPPSR. ears elaborate structures admirably adapted to receive and transmit sound waves. But the external openings of these organs are most surprisingly located. lo-cated. In crickets and long-horn grasshoppers there are two curved slits in the tibia or shin of the foreleg, fore-leg, one on each side, just below the "knee." These are the openings of the ears! Each slit gives access to a tympanum, or "drum," which is connected con-nected with air spaces and nerve endings. end-ings. In the case of the short-horn grasshoppers, the ears occupy an equally unexpected position, viz. at the base of the abdomen. The opening open-ing on either side may be found be neath the wings, just above the attachment at-tachment of the great hind-leg. It will be well, in conclusion, to emphasize em-phasize the fact that the noises made by insects are strictly Instrumental No insect has a "voice" that is, the power of producing sounds by the expulsion ex-pulsion of air from the lungs through the throat and mouth. Indeed, insects have no lungs, nor do they use their mouths for breathing. On the contrary, con-trary, they take in atmospheric air through a number of small openings along the sides of the body. These openings are called "spiracles." They give access to an elaborate system of minute pipes, or "tracheae," which ramify among the insect's living tissues tis-sues and convey to them the oxygen necessary for the discharge of the va , rious vital processes. Just within each spiracle there is an ingenious little valve which is opened and closed by a muscular contraction. The circulation of air, to and fro through the spiracles, spir-acles, is kept up by a constant palpitating palpi-tating movement of the whole abdomen. abdo-men. This may be seen, for example, in a wasp that is regaling itself In the dish of fruit on our table; but in the case of a hibernating queen wasp, the body Is practically motionless the reason being that the insect's dormancy dor-mancy is so complete that It requires scarcely any oxygen to continue in being. be-ing. The nearest approach to a true "voice" among insects is the hum ming sound produced by a mechanism mecha-nism within the spiracles. If we shut up a bee in a box, we shall find that it Is able to hum loudly, even though it may be unable to agitate its wings. The mechanism is too complicated to describe here; but It may be roughiy likened to a wind instrument, such as a cornet. |