3!0 
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— Notolophus and Parorgyia. In Notolophus 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 Notolophus. 
Our most common species belong to Notolophus. 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 
Fig. 376 .—Notolophus leuco- . . . . . , , . 
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. 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 
