UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 443 



Contribution from the Bureau of Entomology, 

 L. O. HOWARD, Chief. 



Washington, D. C. 



September 21, 1916 



THE NEW MEXICO RANGE CATERPILLAR AND ITS 



CONTROL. 1 



By V. L. Wildermuth, Entomological Assistant, and D. J. Caffrey, Scientific 

 Assistant, Cereal and Forage Insect Investigations. 



CONTENTS. 



Page. 



Introduction 1 



General description of the range caterpillar. . 2 



Where the range caterpillar occurs 3 



Its economic importance and great abun- 

 dance 3 



Crops and grasses attacked 4 



Character of the injury 4 



Life history of the range caterpillar 6 



Natural enemies of the range caterpillar 8 



A wilt or rot disease 9 



Destruction by hail 9 



History of the range caterpillar 10 



Control measures 11 



Fig. 1.— The New Mexico range caterpillar: Larva, fourth stage. 

 Much enlarged. (C. N. Ainslie.) 



INTRODUCTION. 



The New Mexico range caterpillar 2 (fig. 1) is regarded as a serious 

 pest by the stockmen and farmers of eastern and southern New 

 Mexico. It devastates 

 large areas of range pas- 

 ture and at one time 

 threatened to destroy 

 the live-stock industry 

 over an area of 30,000 

 square miles. Formerly 

 it fed only upon the range grasses, but of late has changed its feeding 

 habits and now attacks many cultivated crops as well. The present 

 destructive abundance of the pest is probably due to the fact that 

 the natural enemies, in the form of parasitic and predacious insects, 

 birds, and small mammals, were reduced in numbers through some 

 severe climatic condition which, however, did not destroy the cater= 



1 The purpose of this bulletin is to place before the stockmen and farmers of the Southwest the 

 results of investigations carried on during the past three years concerning the control of the New M«X- 

 ico range caterpillar . 



2 Hemileuca oliviae Ckll.; order Lepidoptera, family Saturnijdae, 



51860°— Bull. 443—16 



