TRIFID^E. 27 



with reddish-brown. Wheu young more yellowish-green 

 with a faint yellowish spiracular shade in addition to the 

 other markings. (C. Fenn.) 



The infant larva is semi-transparent, pale grey with the 

 head and dorsal plate dark brown, and the usual raised spots 

 blackish. At this time it, like many other species, does not 

 appear to use the first pair of prolegs, which are small and 

 ill-developed, so that its method of progression resembles 

 that of the group of Nodnw in which these legs are aborted, 

 and which are known as half-loopers. After the third 

 moult this pair of legs has become developed and is used in 

 walking. 



August to May, on almost every description of low-growing 

 plants as well as upon grasses. Moreover the very young 

 larvaj eat the surface of the lower leaves of trees and shrubs 

 and may be fed for some time on birch leaves ; but the ordi- 

 nary habit of the species, which is to hide underground by 

 day and to crawl up at night to feed, is soon assumed. 

 Apparently this species is but little attracted by the young 

 shoots of shrubs in the spring but confines itself then to grass 

 and low-plants. 



Pupa stout, shining, anal extremity with the usual pair of 

 small bristles ; colour mahogany brown, wing and limb-cases 

 darker ; spiracles, divisions of the segments and anal segment 

 black-brown. Under the surface of the ground in a very 

 brittle earthen chamber, which is so readily broken that the 

 pupa, if dug up, appears to have no cocoon. 



This moth is one of the most familiar objects of the summer. 

 No one who has ever been in a haytield can have missed 

 seeing the great bu^izing yellow moths which start up every 

 moment as the hay is moved, dash swiftly away to another 

 shelter, and even then run through the grass in a most lively 

 manner, and Hy again at the least alann. It hides during 

 the day on the ground among grass, herbage, or any con- 

 ceivable shelter, also iu hedges and under thick bushes, and 



