INSECT ENEMIES OF WESTERN FORESTS 



53 



ing them to wither, droop, and die. The adult moth is grayish- 

 brown with wings marked by three whitish bands edged with 

 black tufts and bright orange and an expanse of % to % inch. 



Figure 20. — The pitch nodule moth Petrova metallica: A, Pitch nodule opened 

 to show larval mine; B, larva, X 3; C, pitch nodule with chrysalid pro- 

 truding; D, adult moth, X 1.3; E, nodule opened to show larva surrounded 

 by three parasite pupae and at right adult chalcid fly, parasite of larvae 

 of the pitch nodule moth, X 4. (Drawings by Edmonston.) 



BARK MOTHS 



Some of the species of the genus Laspeyresia are cambium 

 miners, working in the bark of various coniferous trees. Laspey- 

 resia inopiosa Hein. works in the bark of lodgepole pine in Idaho. 

 L. laricana Busck feeds in the cambium of larch and Douglas-fir. 

 L. leucobasis Busck works in the bark of larch and Engelmann 

 spruce. L. populana Busck breeds in the bark of Populus tricho- 

 carpo in Montana and Colorado. 



The cypress twig moth (Laspeyresia cupressana (Kearf.) ) (fig. 

 21) is a small coppery-brown moth with a wing expanse of about 



