INSECT ENEMIES OF WESTERN FORESTS 



41 



dead lateral shoots the damage is often referred to as tip droop. 

 The terminal leaders of young, thrifty trees are seldom killed, but 

 the growth may be shortened. Eucosma sonomana Kearf. in the 

 larval stage bores through the pith of the terminal twigs of pon- 

 derosa pine and Engelmann spruce. E. hohana Kearf. is an och- 

 reous-colored moth with white spots on the forewings and a Aving 

 expanse of about 1 inch. The larvae have been found boring through 

 the pith, cones, and seeds of ponderosa, Jeffrey, and knobcone pines 

 in California and Oregon. E. rescissoriana Hein. is a dark brick- 

 red moth with faint sprinklings of black scales. It has about seven- 

 eighths of an inch wing expanse. The larvae feed through the pith 

 and cones of lodgepole pine in California and Oregon. 



Figure 17. — A pitch nodule moth {Petrova m'etalUca) : A, Pitch nodule opened to show- 

 larval mine ; B, larva, X 3 ; C, pitch nodule with chrysalid protruding ; D, adult moth. 

 X 1.3 ; E, nodule opened to show larva of moth surrounded by three parasite pupae 

 and at right adult chalcid fly, parasite of the larvae of P. luetalUca, x 4. (Drawings 

 by Edmouston.) 



Bark Moths 



Some of the species of the genus Laspeyresia are cambium miners, 

 working in the bark of various coniferous trees. Laspeyresia 

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

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

 leucohasis Busck works in the bark of larch and Engelmann spruce. 



