NOTES, CAPTURES, ETC. Le 
enquires if the larve of Acherontia atropos can produce sound, I 
enclose the report of Mr. E. B. Poulton, of Oxford (who is 
colouring the larve of the Sphingide from living specimens), to 
whom I sent, through Mr. H. B. Spencer, a fine larva in the 
autumn of this year. ‘Thinking the information will be 
interesting, I forward it for your insertion :—‘‘ The fact that 
a sound is emitted by this larva has been often stated, and the 
sound has been compared to the snap that accompanies an 
electric spark. During the past autumn (1885) the larva was 
very common, and I received several specimens; of these only 
one made the sound, as far as my observations went. There is 
no doubt the sound is of a defensive character, and is uttered 
when the animal is irritated, as has been positively stated; thus 
when the larva was handled it generally made the snapping 
sound, and more especially when it was tapped on the head. 
From the observation of one specimen I believe that the sound 
proceeds from the mandibles. These are very large, and have a 
considerable range of movement, so that they can bite over each 
other. On the outer surface of each is 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. The relative position of the mandibles during 
the momentary arrest is here roughly shown. This sudden jerk 
and resisting clash of the hard chitinous 
surfaces is, I believe, the cause of the pre 
sound. One is tempted to suggest an ES 
explanation of the origin of this sound 
so unusual among iarve. When irritated 
or attacked, large larve have the habit of 
biting vigorously in all directions, but without aim, and generally 
with a perfectly fruitless result. Their protection is not of the 
actively defensive kind, because of their peculiar anatomical 
construction, which renders them lable to death from the 
smallest injuries (see Trans. Ent. Soc. Lond., 1885, pp. 321 
et seq., for a further development of this view of the writer). 
Nevertheless when detected, and as a last chance, they make this 
aimless and nearly always useless resistance; the resistance is 
useless because aimless, for the mandibles are moved with great 
ENTOM.—JAN., 1886. D 
