2?8 BRITISH LEPIDOPTERA. 



in length, a larva was seen when teased to spread apart its great 

 arm-like horns, while the fullfed ones did not notice such stimulus. 

 . . . The horns and the six silvery opalescent shining tubercles 

 probably become terrifying by the movements of the larva. The 

 tubercles are turned on and throw out their light suddenly like 

 flashes, and may thus have a deterrent effect on their enemies" 

 ( Proc. Am. Phil. Soc, xxxi., p. 156). It may be well to note here 

 that the rapid jerking movements of some Attacid larvae, when dis- 

 turbed must be of great protective value, e.g., the larva of Citheronia 

 regalis, if touched, jerks its head and thorax vigorously sideways. 

 The larva of this species, and also those of Eacles imperial's, Sphingi- 

 campa bicolor, etc., assume a Sphinx-like attitude. The thoracic and caudal 

 spines of the larva of C. regalis are also somewhat sensitive to touch. 

 The Automerid larva (as represented by Hyperchiria io) has a pair 

 of eversible glands developed on the 1st thoracic, and another pair 

 on the 7th abdominal segment, placed behind the spiracles and 

 between the subdorsal and spiracular row of spines. These persist 

 throughout larval life. They are figured by Packard (lor. cit., pi. ix., 

 fig. n). Similar eversible glands are present (or their position 

 indicated) in the larvae of Hemilenca maia and H. artemis, that in 

 H. maia, by an irregular oval liver-coloured patch behind the first 

 thoracic and 8th abdominal spiracles (Joe. cit., p. 173). Hinkley 

 notes the larvae of Hyperchiria io as " processionaries," and says that, 

 although gregarious when young, they become solitary later. Bacot, 

 however, notes larvae of various sizes living together. They are also 

 said to have* on each segment " five or six tufts of green prickles, 

 terminated by minute black points which prick the hand, if touched, 

 and cause severe smarting." The larvae of Hemileuca maia, also 

 gregarious when young, are reported to have hairs which possess 

 the power of stinging sharply. But just as many Sphingid larvae, in 

 addition to the advantage gained by their peculiar attitude, also rely 

 much for their safety on their resemblance to their environment 

 (see anted, vol. i., pp. 80 et sea.), so Packard notes that he once saw a 

 fine large larva of Telea polyphemus at Providence on chestnut, and 

 was much struck with the resemblance of the outline of the creature's 

 back — the segments being angular so as to render the body serrate, 

 each tooth-like form of the segment surrounded by a tubercle and 

 long hair — to the serrated edge of the leaf, each of the teeth ending 

 in a long hair. Packard considers that it is not improbable that the 

 ancestors of Telea, Act/as, and other species whose larvae have angular 

 segments, may originally have fed on trees with serrated leaves, and that 

 later they adopted as their more usual foodplants such trees as the oak, 

 on which the edges of the leaves are either smooth or simply lobed 

 (Proc. Am. Acad. Arts and Sciences, 1893, p. 86). The fullgrown larva 

 of Callosamia angulifera has the dorsal abdominal tubercles reduced 

 in size to such an extent that they may be said to be obsolete, the 

 larva being simply a large green caterpillar with inconspicuous 

 markings, protected by its green colour like the majority of 

 lepidopterous larvae, and not so strikingly marked as is the fullfed 



* Bacot notes : " This is correct ; it is certainly a poison : the effect very 

 much like nettle-stings but it goes off in an hour or so, having none of the 

 lasting effects exhibited by the urtication due to the hairs of Lachneid or Liparid 

 Jarva: " {in Hit.). 



