U. S. D. A., B. E. Tech. Ser. 20 Pt. III. p. I. I., May 5, 1911. 



TECHNICAL P.APERS ON MISCELLANEOUS FOREST 



INSECTS. 



II. A REVISION OF THE POWDER-POST BEETLES OF THE FA/VIILY 

 LYCTID/E OF THE UNITED STATES AND EUROPE. 



By E. J. Kraus, 

 Expert Preparator, Forest Insect Investigations. 



INTRODUCTORY NOTE. 



[By A. D. Hopkins.] 



This contribution by Mr. Krau.s is based on a study (1) of the material in the 

 forest insect collection and general collections of the Bureau of Entomology and of the 

 United States National Museum and (2) of the types of species described by Doctor 

 Le Conte and Colonel Casey, and of specimens of European species submitted by Mr. 

 Edmund Reitter, of Austria. The family Lyctidse is represented in North America 

 by certain species which are of special economic importance as causing the injury to 

 seasoned wood products known as "powder post." These species have been the sub- 

 ject of extended investigation by the writer and his associates to determine their 

 habits, seasonal history, and practical methods of control. There has, therefore, been 

 special need of a revision of the group to bring the knowledge of systematic facts up to 

 date and to furnish a reliable basis for working up the biological data. 



INTRODUCTION. 



Much has been written regarding the members of the family 

 Lyctidse, especially with respect to their economic importance. 

 There has, however, been considerable doubt as to the correct iden- 

 tity of some of the species, perhaps more especially on account of 

 their enormous variability. In this paper the author has attempted 

 to point out the more prominent specific characters and give some- 

 thing of the range of variation within the species as he has recognized 

 them. For the determination of some of the species he has had occa- 

 sion to examine a series of several hundred specimens. 



Through the courtesy of Col. T. L. Casey, the author has been per- 

 mitted to examine the types of his species. Mr. Samuel Hehshaw, of 

 the Museum of Comparative Zoology at Cambridge, Mass., has kindly 

 permitted him to mak(» a personal examination of the Le Conte types; 

 Dr. Henry Skinner, of the Academy of Natural Sciences, Philadel- 



111 



