Circular no. 8i6 <fi 
August 1949 Washington, D.C. 
UNITED STATES DEPARTMENT OF AGRICULTURE 
Grasshopper Egg-Pod Distribution in the 
Northern Great Plains and Its Relation 
to Egg-Survey Methods 
By E. G. E)avis, entomologist, Division of Cereal and Forage Insect Investigations , and 
F. M. \y adley, statistical consultant, Bureau of Entomology and Plant Quarantine, 
Agricultural Research Administration 1 
CONTENTS 
o / 
Page 
Introduction.. . 2 
Sources of data. 2 
Egg-pod distribution. 3 
In relation to types of 
vegetation habitats. 3 
In fields and margins.* 4 
Sampling and survey methods. 8 
Number and location of 
field-sample units. 9 
SB 945 
.L7 D23 
Copy 1 
Page 
Sampling and survey methods, Cont’d 
Distribution of units within fields 9 
Number of field stops for a 
county or district. 10 
Distribution of stops within a 
county or district. 11 
Time utilization of sampling.... 12 
Discussion. 14 
Conclusions. 15 
iThe authors acknowledge the assistance given by J. R. Parker, in charge of the 
Bozeman, Mont., laboratory, Division of Cereal and Forage Insect Investigations, in 
both the field work and the preparation of the manuscript and by C. M Packard, in 
charge of the Division, for helpful criticism. Members of the staffs of the Montana 
State entomologist’s office, the Division of Grasshopper Control, and the Bozeman 
laboratory aided in much of the field work. 
lAot* 
.ogrop* 
