UNITED STATCS DEPARTMENT OF AGRICULTURE 



In Cooperation with the 

 Connecticut Agricultural Experiment Station 



DEPARTMENT BULLETIN No. 1238 



Washington, D. C. 



October 15, 1924 



THE CANKERWORMS 



B. A. PORTER, Entomologist, and 



C. H. ALDEN, Scientific Assistant, Fruit Insect Investigations, 



Bureau of Entomology 



CONTENTS 



Page 



Introduction 1 



Economic History 2 



Scientific History 3 



Common Names 4 



Differences Between the Species ■ 5 



Food Plants 5 



Distribution 6 



Means of Dissemination 6 



Economic Importance 8 



Fall Canker worm 9 



Spring Cankerworm J 20 



Natural Control 1 28 



Control Measures 32 



Summary 35 



Literature Cited 36 



WASHINGTON 

 GOVERNMENT PRINTING OFFICE 



1924 



