52 
BULLETIN 1476. tf. 5. DEPARTMENT OF AGRICULTURE 
examination of this character in the same field, and to select a field 
for this purpose which showed a relatively light infestation in order 
to secure noninfested stalks. 
Table 11 gives results from two fields of Longfellow flint field corn 
in which the ears and nubbins were removed and weighed from an 
equal number of severely infested and noninfested stalks. In field 
No. 1. located at Stoneham. Mass.. 7^ per cent of the stalks and 66 
per cent of the ears were infested, with a total grain injury of 2.2 
per cent. In field No. 2. located at Wakefield. Mass., practically 100 
per cent of the stalks and 39 per cent of the ears were infested, with 
a total of 1.9 per cent grain injury. In this field it was possible 
to find a sufficient number of noninfested stalks to serve as a com- 
parison. 
Table 11. — Effect of injury caused bu the European corn borer to stalks upon 
the number and weight of field-corn ears 
Total 
• 
exam- 
ined 
in each 
lot 
Infested si 
Noninfested stalks 
Loss in ears 
Loss in 
weight 
Location (Mass.) 
Num- 
ber 
of 
-.- 
Num- W f 8ight 
bins 
Num- 
ber 
of 
ears 
Num- 
ber 
of 
nub- 
bins 
Weight 
::' v.'.rs 
and 
nub- 
bins 
(lbs.) 
Num- Per PnilTu1 . Per 
ber 1 cent ^ 0UI1C ^ cent 
Stoneham 
Wakefield.. 
100 
50 
4« 
12 47. 50 
8 18.00 
99 
51 
13 
4 
51.50 
25.75 
7 
1. 01 
13. 7S 
4.00 
7. 75 30. 10 
Total 
Average 
150 
142 
20 65.50 
150 
17 
77.25 
8 
5l33 . 
11.75 
15. 21 
From Table 11 it appears that in the two fields examined the 
number of ears from the noninfested stalks exceeded those from the 
severely infested stalks by 5.33 per cent, while weight of the ears 
and nubbins from the noninfested stalks exceeded that of the infested 
stalks by 15.21 per cent. The " severely infested " stalks used as a 
basis of comparison were selected with a view to approximating 
average conditions in fields sustaining maximum infestation, and the 
losses shown in Table 11 may therefore be taken as indicative of 
actual loss occasioned by borer injury to the stalks. The percentage 
of loss due to prevention of ear production and reduced weight of 
ears and nubbins, as shown, undoubtedly is exceeded in fields sus- 
taining maximum infestation, but in the absence of accurate means of 
calculating such losses no figures can be given. It is in this class 
and from this cause that the major portion of the gross damage by 
the corn borer occurs, as will be apparent by comparing the figures 
showing direct grain injury with the figures showing indirect grain 
loss through the prevention and reduction of ear (grain) for- 
mation. 
EFFECT OF INJURY TO STALKS UPON" NUMBER OF MARKETABLE EARS 
PRODUCED BY SWEET CORN 
A belief exists among growers of sweet corn in Massachusetts that 
severe injury to the plant.- by the corn borer results in a decrease in 
ihe number of marketable ears produced and an increase in the pro- 
portion of nubbins. In order to investigate this theory, a comparison 
