424 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1923 



When the katydids are singing at night in the woods they appear 

 to be most wary of disturbance, and often the voice of a person ap- 

 proaching or a crackle under foot is sufficient to quiet a singer far 

 overhead. The male in the cage never utters a note until he has been 

 in darkness and quietness for a considerable time. But when he 

 seems to be assured of solitude he starts his music, a sound of 

 tremendous volume in a room, the tones incredibly harsh and rasping 

 at close range, lacking entirely that melody they acquire with space 

 and distance. It is only by extreme caution that the performer may 

 be approached while singing, and even then the brief flash of a light 

 is usually enough to silence those stentorian notes. Yet occasionally 

 a glimpse may be had of the musician as he plays, most frequently 

 standing head downward, the body braced rather stiffly on the legs, 

 the front wings only slightly elevated, the tips of the hind wings 



projecting a little from between 

 them, the abdomen depressed and 

 breathing strongly, the long an- 

 tennal threads waving about in 

 all directions. Each sjdlable ap- 

 pears to be produced by a separate 

 series of vibrations made by a 

 rapid shuffling of the wings, the 

 middle one being more hurried 

 and the last more conclusively 

 stressed, thus producing the sound 

 so suggestive of ka-ty-did,\ ha-ty- 

 did', which is repeated regularly 

 about 60 times a minute on warm 

 nights. Usually at the start and 

 often for some time only two 

 notes are uttered, ka-ty, as if the 

 player has difficulty in falling 

 at once into the full swing of 

 ka-ty -did. 



The structure of the wings and 

 the details of the stridulating 

 parts are shown in Figure 12. 

 The wings (A, B) fold vertically 

 against the sides of the body, but 

 their inner basal parts form wide, 

 stiff, horizontal, triangular flaps 

 that overlap, the left on top of the right. A thick, sunken crosswise 

 vein (fv) at the base of the left tympanum (Tm) is the file vein. It 

 is shown from below at C where the broad, heavy file (/) is seen with 



Fig. 12. — Wings and sound-making organs 

 of the male katydid. A, left front wing 

 showing the greatly enlarged tympanal 

 area (Tm) with its thick file vein (fv). 

 B, base of right wing with large scraper 

 (8) on its inner angle, but with very 

 small file vein. C, under surface of file 

 vein of left wing, showing large, flat, 

 coarse file (f) 



