Circular No. 575 



October 1940 • Washington, D. C. 



UNITED STATES DEPARTMENT OF AGRICULTURE 



Control of the Mormon Cricket by the 

 Use of Poisoned Bait 



By F. T. Cowan, associate entomologist, and H. J. Shipman, junior entomologist, 

 Division of Cereal and Forage Insect Investigations, Bureau of Entomology and 

 Plant Quarantine 



CONTENTS 



Page 

 Introduction 1 



Past and present methods of control 2 



Need for control by poisoned baits 2 



Bait-testing methods 3 



Materials tested 5 



Experiments to determine the best carrier 5 



Experiments to determine the best attractants. 6 

 Experiments to determine the value and most 



efficient strengths of different poisons 7 



Experiments by the wing-pen method to com- 

 pare the more promising baits of previous 



tests 7 



Experiments to determine further the value of 

 the attractants and the most efficient 

 strengths of sodium arsenite and sodium 8 

 fluosilicate . 



Page 

 Experiments to compare new carriers and 



poisons with the best baits of previous tests. . 9 

 Time and temperature for optimum feeding on 



baits io 



Migration and baiting 



Field demonstrations of control by the use of 



poisoned bait 12 



Recommendations for baiting campaigns... 13 



Recommended bait formulas 13 



Mixing the bait 14 



Spreading the bait h 



Precautions 14 



Summary 14 



^ WM yyyy ys 



INTRODUCTION 



The Mormon cricket (Anabrus simplex Hald.) 1 is indigenous to the 

 Northwestern and northern Rocky Mountain States, its range extend- 

 ing north into Canada, south to New Mexico, east to the Missouri 

 River in North Dakota and South Dakota, and west to the Cascade 

 Mountains and the Sierra Nevada. It is a destructive pest, feeding 

 on every class of vegetation, including native grasses and range 

 plants, and on cultivated crops. Widely separated and sporadic 

 outbreaks of the Mormon cricket have been recorded over most of the 

 infested area since 1847. The most general and widespread outbreak, 

 with the exception of the one now being combated, reached its peak 

 in 1904 and 1905. It extended over Colorado, Nevada, Wyoming, 

 and probably Idaho and Montana. The present outbreak has been 

 gradually increasing in scope and intensity since 1920, until Mormon 

 crickets now (1939) are a menace to crops in parts of 11 of the 

 Western States. Improved control methods during the last 3 years 

 have served to protect crops and are gradually decreasing the size 

 and intensity of the outbreak. 



Order Orthoptcra, family Tettieoniidae. 

 235604—40 



