UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 295 



JZ%r < &j-u 



Contribution from the Bureau of Entomology 

 L. O. HOWARD, Chief 



J^'^ro, 



Washington, D. C. 



PROFESSIONAL PAPER 



October 28, 1915 



THE ZIMMERMAN PINE MOTH. 1 



By Josef Brunner, Assistant in Forest Entomology, Forest Insect Investigations. 



CONTENTS. 



Page. 



Description of the insect 2 



Seasonal history and habits 3 



Relation to other insects 5 



Relation to natural enemies 6 



Habitat and host trees 7 



Character of injury and work of larvae 8 



Effect of infestation on tree growth and forest. 9 



Remedy 10 



Conclusion 11 



Literature cited 12 



INTRODUCTION. 



One of the insects of the order Lepidoptera very destructive to 

 coniferous trees, and especially to yellow pine (Pinus ponderosa) in 

 various sections of the West and, according to Zimmerman, Grote, 

 and Kellicott, to white pine (Pinus strobus), Canadian or red pine (P. 

 resinosa), Austrian pine (P. austriaca), Scotch pine (P. sylvestris), 

 Swiss pine (P. cemfoa), and other pines in the East, is the Zimmerman 

 pine moth (Pinipestis zimmermani Grote 2 ). Aside from being 

 largely the cause of " spike-top " (PI. I) in mature timber, it spike-tops, 

 stunts, and kills outright innumerable trees of the so-called "second 

 growth." The timber of at least one area, thus far discovered, has 

 been brought into such ill repute that carpenters and builders refuse 

 to use it for anything in which "never-ending shrinkage" is objec- 

 tionable. 



Having noted during several seasons the severe injuries inflicted by 

 the larvse of this insect, the writer, at the suggestion of Dr. A. D. Hop- 

 kins, undertook, during the autumn of 1912, a systematic study of its 

 seasonal history and habits, the recorded information on this insect 

 being inadequate. This study was conducted during 1913-14 in 

 conjunction with other work on insects which affect reproduction and 



Pinipestis zimmermani Grote. 



2 Identification by August Busck. 



Note. — This bulletin is of special interest to manufacturers and users of pine lumber from the Western 

 States. 



4249°— Bull. 295—15 



