198 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 17 
When making up a statement of the damage done by grasshoppers over a wide 
area, the entomologist should, when possible, compare the yield of damaged sections 
with the yield of localities where there were no grasshoppers but wdiich had other 
limiting factors equal. A comparison of the yield during the grasshopper infestation 
with the yield in the same localities but in years when there were few, if any, grass¬ 
hoppers can be made but before the entomologist can estimate the damage done by 
grasshoppers, he must know the action, during the years under comparison, of other 
limiting factors such as rainfall, temperature, sunshine, winds, and crop diseases. 
Estimating the numbers of an insect which during the daylight is 
almost continually on the move and that becomes disturbed at the first 
unusual movement of the observer is sometimes an exasperating propo¬ 
sition. In 1920 C. L. Corkins, investigating Melanoplus atlanis (Riley), 
by aeroplane in North Dakota, found the bulk of a swarm flying be¬ 
tween five and 600 feet and observed a few stragglers at an altitude of 
1,650 feet above ground. 
In our work with grasshoppers we often have to estimate the num¬ 
ber of eggs in a locality and, later, do the same with both nymphs and 
adults. 
In investigating the number of eggs with the thought of prediction of 
the character of damage in the future, a knowledge of the egg-laying 
habits of the economic species common to the particular section is, of 
course, necessary. A wide variance in the choice of place for oviposition 
occurs with different species in the hard spring wheat area, and to a 
lesser degree this choice differs with the same species in different lo¬ 
calities. The prevailing methods of tillage function importantly in this 
matter. In the Northern Great Plains, Melanoplus bivittatus (Say), 
Melanoplus differentialis (Thomas), Camnula pellucida (Scudder), and 
Dissosteira Carolina (Linnaeus) commonly deposit their eggs in beds 
having rather distinct borders. The eggs of Melanoplus atlanis (Riley) 
are not as commonly placed in beds but more often are scattered over 
wider areas. Consequently, when making estimates of the possibility of 
outbreaks of the first four species previously mentioned, the number 
and size of the egg beds is taken into consideration but with Melanoplus 
atlanis (Riley), the number of pods located is the determining factor. 
In a section where the ground is rocky yet covered with grass or other 
vegetation, the eggs of Melanoplus bivittatus (Say) commonly are found 
at the base of half-buried rocks, as a rule more numerously on the side 
that receives the direct sunlight between noon and four o’clock in the 
afternoon. In some sections the eggs of this species occur in the crowns 
of alfalfa but in the alfalfa regions of western Nebraska and eastern 
Wyoming, these eggs are more often found close to the roots of grass 
