MANDUCA ATROPOS. 453 



a crumpling of the plates forming the integument of the 



abdomen, but in vol. vii., pp. 401 et seq. he retracts and says 



that the sound comes from the head, whilst in vol. ix., p. 125, 



he thinks it may be a humming like that made by bees and 



flies : Abicot {Bull. Soc. Ent. Fiance, ser. 2, i., p. 50; refutes 



Goureau, and Ghiliani {Joe. cit., ser. 2, ii., pp. lxxii-lxxiv) confirms 



Passerini. Paris {Joe. cit., ser. 2, iv., p. cxii) ascribes it to a fluid 



forced up and down inside the haustellum with the assistance of the 



palpi, whilst Landois {Zeits. filr ivissen. Z00L, xvii., p. 162) originally 



reverted to Reaumur's view, saying that it is due to the friction of the 



palpi against the haustellum. Van der Hoeven (Tijds. Ent. Ned. Ver., 



ii., pp. 1 1 7-1 22) says that it proceeds from friction at the posterior end 



of the haustellum; Westmaas {Joe. cit., iii., pp. 120-124) completely 



confirms Passerini and confutes Wagner ; Capronnier says {Ann. Soc. 



Ent. Belg,, x., C.R., pp. 16-17) tnat an imago with a deformed 



head was mute. Newman, Johnson and Taylor {Ent., ii., 1865, 



pp. 284, 325, &c ) repeat the theories of Rosel and Lorey, whilst 



Moseley {Nature, vi., pp. 1 51-153) confirms the theory of Passerini, 



and gives a diagram and description of the cavity and its muscles. 



Swinton himself points out (E.M.M., xiii., p. 218) that authorities are 



divided as to whether the noise is really due to friction or expiration 



He details at length Landois' experiment with the palpi, and states 



that, in good squeakers, he has invariably found a portion of the hair 



at the outer edge of the basal joint ot the palpi worn, and also 



that the sound of the file may, in some slight measure, be reproduced 



after the death of the insect by a gentle friction. Hybernal 



habits : As an expression of ignorance * we are inclined to 



agree with Burrows (Ent. Rec, xiii., p. 156) that the species cannot 



survive even the mildest English winter out-of-doors j. Burrows states 



{Joe. cit.) that, in forcing pupae in October, November and December, 



a temperature of 6o° F. produces the imago in four weeks, one of 7o°-8o° 



F. the imago in two weeks, and 9o°-ioo° F. the imago in one week. 



The higher the temperature the more moisture is required. Carelessness 



in damping results in the loss of the whole stock. Thus forced, the 



earliest emergence has been obtained on September 15th, 1893, 



* Corbett notes [But. Rec, xiii., p. 278) that, for three consecutive years. 

 1899-1901, M. atropos was common in the Doncaster district, and, in the early 

 summer of 1901, an imago captured wild was brought to him, all of which he 

 thinks points to the species having existed naturally in the district for three years. 



t Burrows records {Ent. Rec, vi., p. 291) that a pupa of M. atropos was 

 dug up in early March, 1895, it was dead, probably killed by the severe winter, 

 and all the tail segments were movable owing to the rottenness of the pupa. Glenny 

 notes {Ent. Rec, xiii., p. 157) that a friend of his, with 82 pupae in the autumn of 

 1900, decided to keep them in a cool situation, trying to keep them as nearly as possible 

 so as to imitate their natural surroundings, the result being that every pupa had died 

 by February 20th, 1901. On the other hand, Cambridge obtained 3 pupae in August, 

 1900 (Ent., xxxiv., p. 227), kept them exposed in a room supplied with a fire, with 

 the result that one pupa died, a cripple emerged in October, the third emerged 

 perfect, July nth, 1901. Bowles notes (Ent. Rec., ix., p. 61) that he bred 6 fine 

 imagines of M. atropos in November, 1896, but adds that, as soon as the nights got 

 cold, he began to lose the pupae though the moths were almost matured and ready for 

 emergence ; the pupae appeared to get numbed and feeble ; he then put them in 

 a fairly uniform temperature of 8o° F., and emergence commenced again. 

 Norgate says [loc cit., p. 266) that he had an imago emerge on July 26th, 1897, 

 from an 1896 pupa, which had been kept indoors, whilst during the same winter 

 some 9 or 10 pupae which were left in their puparia, spun in earth in separate 

 flower-pots sunk in the ground and left out-of-doors, all died. 



