MANDUCA ATROPOS. 407 



of electric sparks," whilst Sanders writes (Ent. Wk. Int., iv., p. 196): 

 " The larva makes a crackling noise similar to that made by boys 

 with their thumb-nails, and equally as loud .... sometimes 

 it makes a very rapid- succession of the same noises not unlike 

 that produced from the winding up of a watch," and Burrows says 

 {Ent. Rec, xiii., pp. 155-156): " The larva makes, when irritated, a 

 slight 'clicking' noise, such as one can make with one's finger- 

 nails," whilst Parry observes (Ent. Wk. Int., v., p. 29) that the larva 

 often repeats the noise several times in quick succession. 

 Bartel says (Pal. Gross-Schmett., ii., p. 19): "The fullgrown 

 larva gives out, when irritated, a tolerably loud and clear chirping 

 sound, which is produced by a rubbing together of the mouth- 

 parts." Many other authors have noticed the fact and Paris observes 

 (Ann. Soc. Ent. France, iv., p. cxii) the cry of the larva as being 

 made when the latter is excited. He describes it as softer and 

 shriller than that made by the imago and asserts that, at each cry, a 

 whitish mucous escapes from between the mandibles, and he concludes 

 therefrom that the imaginal tongue is already in process of develop- 

 ment, in the form of a gland that opens between the mandibles, 

 although this could not be proved. Landois describes (Ton- und 

 Stimmap. der Insecten, p. 59) the crackling sound made by the larva 

 as the result of "a testy lateral jerk of the head, due probably to 

 muscular contraction," but Clifford, in spite of the above evidence (Ent., 

 xviii., p. 302), questioned whether the larva could produce a sound, as 

 one he had was obstinately silent, whilst he further stated that 

 Fuessly first asserted the fact, and that Newman had confirmed it. 

 Anderson then wrote to maintain (loc. cit., p. 324) that the larva 

 could make a noise which, he reiterated, exactly resembles the 

 sound made by an electric spark, although he could not tell how 

 it was caused. Poulton observes (Ent., xix., p. 17) that, of several 

 larvae kept under observation in 1885, only one made any sound. 

 The noise he said was evidently of a defensive character, was 

 made when the larva was irritated, especially if handled, or tapped 

 on the head. The sound, he considers, proceeds from tbe mandibles 

 which are very large, and have a considerable range of movement, so 

 that they can bite over each other. On the outer surface of each 

 mandible there is, he says, a transverse tuberculated ridge, and when 

 one mandible is outside the other, and is gliding over the outer 

 surface of the latter towards its base, it is momentarily arrested 

 by the ridge, but passes over it with a jerk, that causes sharp 

 collision with the outer surface on the basal side of the ridge. 

 This sudden jerk and resisting clash of the hard chitinous surface 

 is, he believes, the cause of the sound. He further notes that the 

 sound may be protective. Aigner-Abafi confirms {/litis. Zeits. fur 

 Ent., iv., p. 356) this view, and gives a sketch of the mandibles, 

 stating that the sound is produced by the mandibles, which are 

 provided with notched teeth, being brought sharply together. The same 

 explanation had many years previously been given by Capronnier. 

 The views of Kleemann, who also stated that the sound was caused 

 by the movement of the jaws, and others are also quoted. Pearce 

 observes (Ent., xix., p. 44) that he heard the snapping noise made by 

 the larva of this species on two or three occasions, in 1885, and 

 believes it to have been made by gnashing the mandibles. Morres 



