OWLET-MOTHS. 435 



the hindmost pair, and never raise the end of the body when 

 at rest. Some of them make cocoons, but the rest go into 

 the ground to transform. Many of the Noctuas vary more 

 or less from the characters above given, and the tribe seems 

 to admit of being divided into several smaller groups or 

 families, under which their peculiarities might be more dis- 

 tinctly pointed out. Unfortunately the history of most of 

 our moths is still imperfectly known ; and for this reason, as 

 well as on account of the length to which the foregoing part 

 of this treatise has already extended, I have concluded to 

 suppress a considerable portion of my observations on the 

 owlet-moths and the rest of the JLepidojatera, and shall con- 

 fine my remarks to a few of the most injurious species in 

 each of the remaining tribes. 



The injury done to vegetation by the caterpillars of the 

 Noctuas, or owlet-moths, is by no means inconsiderable, and 

 sometimes becomes very great and apparent; but most of 

 these insects are concealed from our observation during the 

 day-time, and come out from their retreats to feed only at 

 night. To turn them out of their hiding-places becomes 

 sometimes absolutely necessary, and it is only by dear-bought 

 experience that we learn how to discover them. This is not 

 the case with all ; those of the first family, which I would 

 call Acronyctians (AcronyctadjE*), live exposed on the 

 leaves of trees and shrubs. They have sixteen legs, are 

 cylindrical, and more or less hairy, some of them closely 

 resembling those of the genus Obstera, having a wart or 

 prominence on the top of the fourth and the eleventh rings, 

 and some of them have the hair in tufts like Arctians and 

 Liparians. They make tough silken cocoons, in texture 

 almost like stiff brown paper, into which they weave the 

 hairs of their bodies. Their moths have bristle-formed 

 antennas, and the thorax is not crested. Their fore wings 

 are generally light gray with dark spots, and in many are 

 marked with a character resembling the Greek letter ty near 



* From Acronycta, a genus of moths appearing at nightfall, as the name implies. 

 55* 



