110 Journal New York Entomological Society. [Vol. xiii. 



if the larva is left in peace it keeps perfectly quiet, but when the larva- 

 cage is touched, or the larvae are taken out, they make this peculiar 

 tapping sound, resembling the ticking of a watch. In the fifth stage, 

 singularly enough, the larvae could not be made to tap, but this might 

 possibly have been due to unfavorable climatic conditions. 



The Finnish species of the genus Drepana, namely, curvatula, 

 lacertinaria and falcataria, produce, like the Drepana arena fa, by 

 rubbing the anal segment against the surface of the leaf, a peculiar 

 scraping (rasping) sound. This sound, which is also tolerably loud, 

 arises from the friction of two small chitinous teeth against the leaf. 

 The chitin formations in question, which are somewhat dissimilar in 

 the different species, are evidently rudiments of the vanished anal 

 legs, which the adjacent hairs clearly indicate, as they occupy the 

 same position round the chitin hooks as round the anal legs in the 

 allied forms. 



The Dicranura as well as the Centra species make, when dis- 

 turbed, a loud scraping sound by swinging the foremost part of the 

 body from one side to the other, thereby pressing the mouth-parts 

 against the surface of the leaf. This peculiarity seems to belong to 

 all Notodontious caterpillars, although to none in so great a degree as 

 to the genera named. 



Finally I will again repeat what Staudinger * relates of a species 

 from the Amur district, Smerinthus dissitnilis 15rem., which goes to 

 prove that not only larvae, but also pupae can produce sound. " The 

 caterpillar, like the pupa of this species, makes, on being disturbed, a 

 tolerably loud sound. Graeser calls the same whistling : that which 

 I have heard from pupae 1 might call rattling. The peculiar pupa, 

 which is somewhat flattened on the ventral side and rough all over, 

 has, at the extremity of the three middle segments of the body short, 

 strong indentations and can, like the Kentrochrysalis streckeri Staud., 

 move onwards with tolerable celerity.'' 



That all the sound-productions mentioned here are a means of in- 

 timidation at the disposal of the larvae, there can scarcely exist any 

 doubt. 



*Memoires sur les Lepidopleres. N. M. Romanoft, Tome VI, 1892, p. 232, 

 PI. IV, fig. 3. 



