64 THE CANADIAN ENTOMOLOGIST. 



THE ECOLOGY OF INSECT SOUNDS. 



BY FRANK E. LUTZ, UNIVERSITY OF CHICAGO. 



" Ecology," as it is coming to be universally considered, is the science 

 of cause. It is constantly asking " Why?" and not until we can answer 

 '• because," have we solved a problem in Ecology. It is the capping stone 

 of the other branches of biological investigation. Morphology describes 

 an organ or character; physiology shows us how it works and what it does; 

 ecology, building on these, tells how and why the character or organ 

 arose. It, then, must be considered as more than the old Natural History. 

 Although the value of the latter cannot be overestimated, more must 

 sooner or later be done. 



This is well illustrated in the case of insect sounds. No biological 

 subject has been more written about in popular publications — prose and 

 poetry alike being noisy with references to the insect musicians. A large 

 amount of strictly scientific work has also been done, and while there is 

 much still to do, we, nevertheless, have a fairly clear idea of the anatomy 

 of sound-producing organs, their taxonomic distribution (t), the methods 

 of using them, some of the influences of external conditions (2), and many 

 hypotheses as to functions of the sounds. But we know comparatively 

 little as to why a cricket, for instance, stridulates with his wings, while a 

 beetle rasps with his abdomen, or a cicada possesses such a complicated 

 musical apparatus. 



The translation (3) of J. Portchinsky's ('86) paper in Horpe Societatis 

 Entomologies Rossicre. Vol. XX., pp. 111-127, has, however, suggested a 

 fruitful line of investigation. Considering the Orthoptera, he calls atten- 

 tion to the fact that the Acrididre — unlike their relatives, the crickets and 

 the long-horned grasshoppers — -do not stridulate with their wings, but rub 

 " the femur against the raised meshvvork of veinlets upon the tegmina." 

 Another striking difference between this family and the other families of 

 the order is that here, alone, we get the bright colouring of the inner 

 surface of the hind legs. These are often the only bright colours the 

 insect possesses. It has become an axiom that insects are constantly 

 endeavouring to show their be.uity— especially if it bz a secondary char- 



( 1 ) Swinton, Insect Variety. 



(2) Dolbear, A. E., Amer. Natur., Vol. XL, No. 371, pp. 970-971. Riley, C. \\, 

 Proc. Amer. Assoc. Adv. Science. XXXIV., 1885, pp. 330-332. Scudder, S. II., 

 Proc. Bosi. Soc. Nat. Hist.. Vol. XL, 1868, pp. 306-313 and 316. 



(3) Ent. Record and Journal of Var. (1901), Vol. XIII. . No. <). 



