April, ’24] 
LOCKWOOD: GRASSHOPPER DAMAGE 
201 
the roots left in the ground but this occasionally occurs. Where the 
grasshoppers are uniformly numerous in a growing field the damage they 
do is not so easily seen unless .it be of a high percentage. Well-developed 
growing grain may be severely checked, yet mature a very good crop 
later on if the grasshoppers are killed. The yield of hay taken from an 
infested field when compared with the production during years when 
there were no grasshoppers, other factors being equal, presents a 
definite idea of the damage done to forage crops. In the case of either 
cereal or field crops, grown for seed, and which are nearing maturity 
before grasshoppers occur in the held, the percentage of damage done 
may be estimated by examining different parts of the held and by count¬ 
ing the chewed kernels, dropped heads or seed balls in a predetermined 
unit and comparing this count with the seed in undamaged areas. 
This is the method that adjusters commonly use to ascertain the damage 
to a crop by hail. 
In making up a statement of grasshopper damage for a state or even a 
county, the aid of several people is needed unless the entomologist has 
spent the entire time in a district where the estimate is made, and, 
even then, a close knowledge of past crop values is needed. We cannot 
conceive that the observations of a single person could be sufficiently 
accurate for him to properly estimate the damage done by grasshoppers in 
an entire state; at least, in a state so large as those in the northern plains. 
When working with such a problem, we ask and receive aid from other 
agricultural workers. County agricultural agents furnish information as 
to the acreage infested and the intensity of the infestation. Such in¬ 
formation often is furnished, plotted on county maps and shaded to 
represent the degree of infestation. They also submit their own esti¬ 
mates of damage done. This is compared with information obtained 
from other sources. 
Limiting factors other than grasshoppers must be taken into con¬ 
sideration. From plant pathologists and agronomists the general con¬ 
dition of the crop and the prevalence of plant diseases is obtained. 
From the reports of climatological observers we obtain the departure 
from normal of precipitation, temperature, wind, and number of days of 
sunshine. From the reports of crop statisticians the production of the 
crops the grasshoppers have damaged is obtained and this is compared 
with the normal production and the production during years when grass¬ 
hoppers were not prevalent. When possible the production in damaged 
sections is compared with that of adjacent districts having other factors 
equal. A compilation of reports received from those whose crops have 
