238 Forestry Quarterly. 



Conk Borer vs. Squirrel. 

 An Important Correction. 



Mr. J. i\I. Miller, Entomological Assistant, Branch of Forest 

 Insect Investigations, Bureau of Entomology, and in charge of 

 investigations of insect damage to forest tree seeds, writes the 

 following : 



The January number of the Proceedings of the Society of 

 American Foresters (Vol. IX, No. i) contains two articles on 

 squirrels and sugar pine reproduction (pages 95-101). These 

 articles are of some interest as I note that the description of 

 damage to sugar pine cones, which is ascribed by both authors to 

 squirrels', corresponds to that which I have usually found to be 

 caused by the cone beetle. I would be interested to know just 

 how close an examination was made of the sugar pine cones which 

 were found on the ground during July and the first part of 

 August. In Mr. Jotter's observations of August 20, 191 1, he re- 

 cords 75 cones on the ground and only 6 of them eaten by 

 squirrels, but the squirrel is evidently assumed as the cause of all 

 the damage. There is a question as to whether or not the re- 

 maining 69 cones showed teeth marks on the stem, which would 

 indicate that they had been cut by rodents. I have examined great 

 numbers of these cones which fall before maturing, yet have very 

 rarely found the teeth marks of squirrels until just before the 

 seed was ready to ripen. Practically all of these fallen cones did 

 show, however, the attack of the cone beetle. Usually there was 

 a tiny mass of pitch on the stem to indicate the entrance of the 

 beetle, but where this was lacking either the beetle or presence of 

 its attack could nearly always be found by close examination and 

 sectioning of the stem. I am satisfied from observations made in 

 different localities in California, that 90% of the damage to im- 

 mature sugar pine cones, ordinarily referred to the squirrel, is 

 caused by the cone beetle. 



This hardly seems fair to the squirrel. Both of these articles 

 would indicate that the gray squirrel cuts the greater portion of 

 the sugar pine crop before it ripens, thereby deliberately destroy- 

 ing its own food supply. It is also worth noting that the exter- 

 mination of the squirrel is recommended as a measure for pre- 



