THE STUDY OF INSECTS. 



spicuous tufts of hairs on the dorsal aspect of the abdomen, 

 and at each end of the body there are long pencils of hairs; 

 on the sixth and seventh abdominal segments there is on 

 the middle of the back of each an eversible gland supposed 

 to be a scent-organ similar to the osmateria in the larvae of 

 Papilio, and it is stated that a fine spray of liquid is some- 

 times thrown from them. 



Excepting a few rare forms, our native species fall into 

 two genera NotolopJins and Par orgy ia. In NotolophiiS the 

 males have short, broad wings ; the females are nearly 

 wingless. In Parorgyia both sexes are winged, and the 

 wings are relatively longer than in NotolopJins. 



Our most common species belong to Notohplius. Of this 

 genus the three best-known species are the following : 



The White-marked Tussock-moth, Notolophus leucostigma 

 (No-tol'o-phus leu-co-stig'ma). This is our most common rep- 

 resentative of the family. It frequently 

 occurs in such great numbers that it 

 seriously injures the foliage of shade- 

 trees and orchards. The male (Fig. 

 376) is of an ashy gray color ; the fore 

 stigma. wings are crossed by undulated bands 



of darker shade and bear a conspicuous white spot near the 

 anal angle. The female is white and resembles a hairy grub 



FIG. 376. Notohplnis leuco- 



FIG. 377. Notolophus leucostigma, larva. 



more than a moth. She emerges from her cocoon and 

 after pairing lays her eggs upon it, covering them with a 



