Technical Series No. 20. 



U. S. DEPARTMENT OF AGRICULTURE, 



BTJRB^XJ OW ENTO]yrOIL.O&Y. 



L. O. HOWARD. Entomologist and Chief of Bureau. 



TECHNICAL PAPERS ON MISCELLANEOUS 

 FOREST INSECTS. 



I. CONTRIBUTIONS TOWARD A MONOGRAPH OF THE BARK- WEEVILS 

 OF THE GENUS PISSODES. 



By A. D. HOPKINS, In Charge of Forest Insect Investigations. 



II. THE GENOTYPES OF THE SAWFLIES ANI) WOODWASPS. OR 

 THE SUPERFAMILY TENTHREDINOIDEA. 



By S. A. ROHWER, Specialist in Forest Hymenoptera. 



III. A REVISION OF THE POWDER-POST BEETLES OF THE FAMILY LYCTID.'E 

 OF THE UNITED STATES AND EUROPE. 



By E. J. KRAUS, Expert Preparator, Forest Insect Investigations. 



Appendix. NOTES ON HABITS AND DISTRIBUTION 

 WITH LIST OF DESCRIBED SPECIES. 



By A. D. HOPKINS, In Charge oj Forest Insect Investigations. 



IV. STUDIES IN THE SAWFLY GENUS HOPLOCAMPA. 



By S. A. ROHWER, Specialist in Forest Hymenoptera. 



V. A PRELIMINARY SYNOPSIS OF CERAMBYCOID UMM. 



By J. L. WEBB, Entomological Assistant. 



VI. CHALCIDIDS INJURIOUS TO FOREST-TREE SEEDS. 



By S. A. ROHWER, Specialist in Forest Hymenoptera. 



WASHINGTON: 

 GOVERNMENT PRINTING OPFUIK 



l'J21. 



