INSECT ENEMIES OF WESTERN FORESTS 



19 



FIR CONE MOTHS 



Cones of white fir, red fir, and other balsam firs, and of Douglas 

 fir, are most seriously injured by the attack of small moths of the 

 genus Barbara (formerly Evetria). The yellowish- white caterpillars 

 mine through scales and seeds, making a tortuous resinous tunnel and 

 an opening at the surface through which resin and larval castings 

 exude. The pupae overwinter near the axis of the cone in a papery, 

 resin-coated cocoon among the resin-matted scales. The adults, which 

 are gray moths about one-half inch in length and w^ith speckled fore- 

 wings, emerge the following spring and lay their eggs on the young 

 budding tender cones. The several species and varieties listed below 

 cause this type of damage : 



Species Plosts and distribution 



Barbara colfaxiana Kearf Douglas fir. California, Oregon, Washing- 

 ton, and British Columbia. 

 Barbara colfaxiana var. taxlfoll- 



ella Busck Donglas fir. Idaho and Montana. 



Baf^bara colfaxiana var. coloradeu- 



sis Hein JJonglas fir and white fir. Colorado. 



Barbara colfaxiana var. stskiyou- 



ana Kearf White fir and red fir. California and 



Oregon. 

 Barbara ulteriorana Hein Douglas fir. Oregon. 



Similar damage to fir cones is frequently caused by the caterpillars 

 of the cone pyralid, and the fir cone geometrid. 



The cone pyralid, Dio- 

 ryctria abietella D. and S. 

 (fig. 7), in the full grown 

 larval stage is a large, ac- 

 tive, irridescent, greenish- 

 red caterpillar three- fourths 

 of an inch in length, which 

 bores through scales and 

 seeds of Douglas fir, bal- 

 sam fir, pine, and spruce 

 cones, leaving a round clean- 

 cut hole. In contrast to 

 the work of Barbara its 

 w^ebbed castings on the sur- 

 face of an infested cone are 

 free from pitch. The adults 

 are gray moths mottled 

 with black and have a wing 

 expanse of about 1 inch. 



The fir cone geometrid 

 Eucymatoge spermapha.ga 

 Dyar in the adult stage is a 

 gray moth with black and 

 red-brown markings and a 



wing expanse of about 1 inch. The caterpillars, which are somewhat 

 similar to the above, are of the measuring worm type. They bore 

 through seeds and cone scales of Douglas fir, the balsam firs, mountain 

 hemlock and i^robably other conifers. 



Figure 7. — A fir cone moth {Dioryctria ahieteUa) , 

 slightly enlarged, and typical damage to Douglas 

 fir cones. (Drawings by Edmonston.) 



