a 



CONES ATTACKED BY THE CONE BEETLE. 



These sugar pine cones show effects of the cone beetle attack at different stages of the 

 growth of the cone. The longer cone, about 14 inches in length, resisted attack, 

 while the others were killed. 



PESTS IN FOREST SEEDS 



COLLECTORS of forest seeds, 

 particularly on the Pacific 

 Coast, are recommended by the 

 United States Department of 

 Agriculture to make certain that the 

 areas in which they work are not in- 



j 



fested by insects which damage the 

 cones and seeds of cone-bearing trees. 

 This damage may readily be sufficient 

 to interfere seriously with the profits of 

 seed-collecting. It has been found, for 

 instance, that much of the white fir 

 seed gathered recently for use in the 

 Western national forests is worthless. 

 In order to avoid, therefore, the waste 

 of time and money involved in collect- 

 ing diseased seeds, the Department ad- 

 vises the careful inspection of sample 

 cones. If cones of the past season are 

 examined during the winter and spring, 

 they will indicate whether or not their 

 particular area is infested, and in July 

 and August, before the seed matures, 

 infested cones will usually reveal imma- 

 ture stages of the insects. 



The insects, which feed upon the 

 seeds, may be found in almost any part 



588 



of the cone or seen but. with the excep- 

 tion of cone beetles, adult insects are 

 rarely seen in the immature cone. In 

 their immature stages, however, these 

 insects depend for their food chiefly 

 upon the cone scales and seeds, doing 

 great damage before the seed ripens. 



In the case of the pine, cone beetles 

 and some of the cone worms kill the 

 cones when small and immature and 

 before the seeds are filled. Damage of 

 this type is easily recognized and can be 

 estimated after the middle of July. 

 Cones affected in this way are called 

 blighted. In other forms of injury, the 

 cone is not killed but the seeds are 

 ruined by the feeding of larvae. Dam- 

 age of this kind occurs in every species 

 of conifer and is frequently caused by 

 caterpillars. In California and southern 

 Oregon in 1912, from 50 to 90 per cent 

 of the seed crop of Western yellow pine 

 and Jeffrey pine was damaged in this 

 way, although sometimes there was 

 nothing on the surface of the cone to 

 indicate that it was affected. 



This is also true of wormy seed, 



