NO. 6 



CATERPILLAR AND BUTTERFLY — SNODGRASS 



13 



A larva of the primitive lepidopterous family Eriocraniidae, Mne- 

 monica auricyania (fig. 6 E), as shown by Busck and Boving (1914), 

 has a small head and a simple tapering body of 13 segments, but being 

 a leaf miner it lacks both thoracic and abdominal legs. It is in the 

 Hepialidae that we first encounter a typical caterpillar (F), though 

 in this case a stem borer. 



Fig. 6. — Larvae of Micropterygidae and lower Lepidoptera. (A, from Tillyard, 

 1922; B,C,D, from Chapman, 1894; E, from Busck and Boving, 1914O 



A, Sabatinca barbarica (Micropterygidae). B, Eriocephala calthella (Mi- 

 cropterygidae). C, Same, antenna. D, Same, abdominal "proleg." E, Mne- 

 monica auricyanea (Eriocraniidae). F, Hepialus sp. (Hepialidae). 



To effectively perform its function of feeding, after the adult had 

 adopted a nectar diet it was first necessary for the caterpillar to have 

 strong biting-and-chewing mandibles, and these it inherited from its 

 ancestors. At the same time it needed a stomach of a size capable of 

 digesting a constant supply of leafy food, and this the modern cater- 

 pillar has. Descriptions of the alimentary canal of various caterpillar 

 species may be found in the papers here cited by Bordas (1911), 

 Peterson (1912), Stober (1927), Neiswander (1935), Woke (1941), 

 El-Sawaf (1950), and Teotia and Pathak (1957). 



The alimentary canal of a typical caterpillar almost fills the body 

 (fig. 7). Beginning with the pharyngeal region (Phy) following 

 the mouth (Mth) a narrow oesophagus (Oe) curves back through 

 the head and in some species expands in the thorax into a huge, 

 strongly muscular crop (CV). The crop is followed by a long, thick 



