NOCTUIDAE 415 



otherwise so constant that the classification of the family is 

 largely based on it. 



The larvae are as a rule destitute of the remarkable adorn- 

 ments of hairs and armatures of spines that are so common in 

 many of the families we have previously considered ; they are 

 fond of concealing tliemselves during the day and coming out at 

 night to feetl ; many of them pass most of their time at, or 

 beneath, the surface of the ground, finding nourishment in roots 

 or the lower parts of the stems of plants ; this is notably the 

 case in the genus Agrotis, which is perhaps the most widely 

 distributed of all the genera of moths. Such caterpillars are 

 known as Cut-worms in North America.^ The great resemblance, 

 inter se, of certain of these Cut-worms, much astonished the 

 American naturalist Harris, who found that larvae almost per- 

 fectly similar produced very different moths. The majority of 

 Noctuid larvae have the usual numl>er of legs, viz., three pairs 

 of thoracic legs, four pairs of abdominal feet and the terminal 

 claspers. In some divisions of the family there is a departure 

 from this arrangement, and the abdominal feet are reduced to 

 three, or even to two, pairs. One or two larvae are known — e.g. 

 Buclidia mi — in which the claspers have not the usual function, 

 but are free terminal appendages. When the abdominal legs 

 are reduced in number (Plusia, e.g.) the larvae are said to be 

 Half-loopers, or Semi-loopers, as they assume to some extent the 

 peculiar mode of progression of the Greometrid larvae, which are 

 know^n as Loopers. In the case of certain larvae, e.g. Triphacna, 

 that have the normal number of feet, it has been observed that 

 when first hatched, the one or two anterior pairs of the abdom- 

 inal set are ill developed, and the larvae do not use them for 

 walking. This is the case 

 with the young larva of our 

 British Breplios notlia (Fig. 

 203). Subsequently, liow- 

 ever, this larva undergoes 



a considerable change, and Fig. 203. — ^rc^^os notlm. Larva, newly 



J , „ , hatched. Britain. 



appears m the form shown 



in Fig. 204. This interesting larva joins together two or three 



^ Although this term is widely used iu North America, it is not in use in Eng- 

 land, though it may possibly have originated in Scotland. See Slingerland, Bull. 

 Cornell University Exp. Stat. 104, 1895, p, 555. 



