10 BRITISH MOTHS 



chiefly feeds upon the flowers and leaves of the potato and jasmine, but is occasionally found on other plants, as 

 the woody nightshade, thorn-apple, elder, spindle-tree, &c. It is but rarely seen, as it feeds by night, concealing 

 itself in the day under the leaves and in the earth. It is full-grown in August and September, when it descends 

 to a considerable depth under-ground to undergo its transformations, which, unlike those of the majority of the 

 family, (and rendered more singular by the size of the insect,) are efi"ected in a few weeks ; the moth appearing at 

 the end of September or beginning of October. Previously to the moth being hatched, the pupa has been observed 

 by Sir. Curtis to eject some moisture from the two spiracles in front of the thorax, and when it bursts forth the 

 antennte and limbs are enveloped in a thin pellicle, like tissue-paper, which prevents them from adhering, and 

 which drops oft' as they expand ; the wings attaining their full size in a couple of hours. 



The large size of the insect, its singularly-marked thorax, and the peculiar noise it emits, have rendered 

 it an object of terror with the vulgar, by whom it has been regarded with dread as the harbinger of 

 pestilence and forerunner of death. Latreille tells us that it appeared one year in Brittany in great numbers, 

 and as at this period an epidemic malady was raging with much violence, the mortality was attributed by the 

 ignorant to this harmless moth. 



Much discussion has taken place relative to the mode in which the squeaking sound mentioned above is 

 produced, and which is emitted by both sexes when alarmed, but at present no satisfactory conclusion has been 

 obtained upon the subject. An interesting memoir has recently been published in the " Annales de la 

 Society Entomologique de France" for 1839, detailing a series of observations made in conjunction, with 

 a view to the determination of the question, by Messrs. Duponchel, sen. and jun., Anbe, Boisduval, Pierret, 

 and Rambur. 



Reaumur attributes the sound to the friction of the proboscis against the palpi, and the inner surface of the 

 second joint of the latter organs exhibits a peculiar structure, not unfitted for the propagation of such a sound. 

 M. dc Johet, however, having deprived a specimen of its proboscis and palpi, found that the noise was still produced, 

 especially when the wings were put in motion ; he accordingly considers that this motion acting upon the air 

 contained beneath the scales of the front of the thorax, is the cause of the sound ; more especially as a specimen 

 when deprived of these scales was mute. Another observer, M. Lorey, conceived that he had detected the cause 

 in the rushing of the air through two trachea3 at the base of the abdomen, which, in repose, are concealed beneath 

 two pencils of hairs, and which are dilated into a star when the noise is produced *. M. Passerini considered 

 that the sound was produced in tlie interior of the front of the head, being emitted from a cavity which 

 communicates with the canal of the proboscis, and in which are placed the requisite muscles for the elevation 

 and depression of this organ, the former movement causing the air to enter into, and the latter to expel it from the 

 cavity — in fact the noise was continued although both the proboscis and abdomen were cut oft", whereas it entirely 

 ceased when the muscles were either cut tlu'ough or traversed by a strong pin thrust vertically into tlie head. 

 More recently, M. Goureau {Annales, 1837) has suggested that the sound is produced by the apparatus described 

 by M. Lorcy ; but that as the apertures in question are not perforated (thus not being spiracles) the sound must 

 be produced in a manner analogous to that of the Cicadw. All these suggestions have been proved by the 

 experiments of the committee of French Lepidopterists, mentioned above, to be without foundation. That of 



* M. Alex. Norilmann, unacquainted with the researches of M. Lorey, adopted the same opinion, iu a memoii' read before the Academy 

 of Sciences at St. Petersburgh on the 8th of December, 1 H37. 



