46 BULLETIN 1476, U. 3. DEPARTMENT OE AGRICULTURE 
The figures in Table 6 show an important amount of direct loss 
from ear infestation and grain injury to both flint and sweet corn. 
The susceptibility to infestation of flint field corn and sweet corn 
was nearly equal in these fields as shown by the average percentages 
of stalk infestation of 76.6 and 77.5 for the flint and sweet types, 
respectively. The difference between the percentages of ear infes- 
tation and grain injury of the two types is due to the fact that the 
sweet-corn ears are harvested before maturity, and therefore are 
exposed to injury for a shorter period than the flint corn. 
During 1922 a series of examinations were made throughout the 
season in 50 fields of sweet corn, aggregating 63.5 acres, taken at 
random in 20 towns of the Xew England area. These examinations 
Avere made at harvest (roasting-ear stage) and on a basis of 100 
ears and 100 stalks to each field. In 9 of these fields none of the 
ears were infested. In the remaining 41 fields the percentage of 
ears infested ranged from 1 to 100. the average for the entire 50 
fields (5.000 ears) being 20.4 per cent. The stalk" infestation for the 
50 fields averaged 56.5 per cent. The majority of the ears found 
to be infested were unfit for market. A similar examination con- 
ducted in 66 fields of the Xew England area during 1923 gave an 
average ear infestation of 10.6 per cent, and during 1924 an average 
of only 1.2 per cent of the sweet -corn ears were found infested in 
52 fields of the same area. 
As a part of the investigation to determine the progress of annual 
increase or decrease of infestation, careful counts were made in 
1921 and 1922 in the cornfields of 40 townships of Xew England. 
representing all conditions of infestation from the center of the 
area to the lightly infested townships near the border of the area. 
In these field counts 10 fields (or garden patches in residential 
districts) were selected in each town, such selections being made on 
the basis of the personal judgment of the field worker as to what 
constituted fields which were representative of the entire town. In 
figuring the averages the results from all fields, whether infested or 
noninfested. were included. 
The majority of these fields were, of necessity, sweet corn. These 
counts show that in 1921 an average of 29.93 per cent of the stalks 
were infested in these 40 toAvns. including noninfested as well as 
infested fields, with an average of 4.44 larvae per infested stalk 
(132.9 larvae per 1<)0 stalks) : while in 1922 an average of 53.29 per 
cent of the stalks were infested in these same towns, with an average 
of 8.75 larvae per infested stalk (466.3 larvae per 100 stalks). These 
figures are believed to represent accurately the average conditions 
throughout the New England area for this two-year period. Com- 
parable figures for the 1923 field survey show that in the 222 fields 
examined in 22 of the same towns included in the 1921 and 1922 
surveys there were an average of 30.1 per cent of the stalks in- 
fested, containing an average of 3.8 larvae per infested stalk (114.5 
larvae per 100 stalks) : while in 1924 there were an average of 18.2 
per cent of the stalks infested in the 178 fields examined in 35 of 
the same towns included in the 1923 survey, containing an average 
of 2.2 larvae per infested stalk (40 larvae per 100 infested stalks). 
The annual surveys have shown a very significant decrease in the 
acreage planted to corn each year, especially in that portion of the 
