Technical Series, No. 20, Part IV. 



U. S. DEPARTMENT OF AGRICULTURE, 



' BXJREj^XJ of KISTTOINIOLOGY. 



L. 0. HOWARD, Entomologist and Chief of Bureau. 



TECHNICAL PAPERS ON MISCELLANEODS 

 FOREST INSECTS. 



IV. STUDIES IN THE SAWFLY GENUS 

 HOPLOCAMPA. 



S. A. ROHWER, 



Agent and Expert. 



I.SSUED May 27, 1911. 



WASHINGTON : 



GOVERNMENT PRINTING OFFICE. 



1911. 



