78 
NUMBER OF LARViE ON A SINGLE PLANT. 
As before mentioned, a large number of young larvae may be present 
in a single ear of corn, but of these never more than one, two, or less 
frequently three mature. On cotton the number present on each 
plant is so variable that records of this sort can have no permanent 
value. The injury corresponds closely to the number of larv«, and 
estimates are best made b}^ noting the extent of the injury. 
EELATION TO THE NUMBER OF EGGS LAID. 
The most important fact to be noted is the wholesale destruction 
which takes place among the young larvae. At times when nearly one 
hundred eggs are present on a single ear of corn, and but two larvae 
can mature, the elimination reaches 98 per cent. On cotton the num- 
ber of eggs laid per plant is considerably less, and the proportion of 
larvae to mature so much the greater. 
PERCENTAGE OF CORN PLANTS INFESTED. 
In the early part of the season, as has already been pointed out, 
injury to corn b}" the first generation of larvae is not great, but increases 
later with the appearance of the second brood. This is shown in the 
following table, compiled from observations of over 6,500 corn plants 
made at Paris, Tex. : 
Table XXVIII. — Percentage of infestation in early corn. 
Date. 
May 
1 
May 
18 
May 
24 
May 
24 
May 
24 
May 
24 
May 
81 
May 
81 
June 
16 
July 
18 
July 
20 
July 
20 
July 
20 
July 
21 
Sept 
28 
Age of corn. 
18 to 24 inches . 
2itp3ifeet 
8 feet 
do 
4 to 6 feet, tassellng 
3 to 4 feet, tasseling 
3 to 5 feet, tasseling 
Silk and tassel 
Roasting ears 
do 
do 
Number of 
Number 
Number 
obserya- 
of 
of 
tions. 
laryse. 
injuries. 
1,000 
1 
1 
650 
2 
6 
1,200 
9 
16 
170 
2 
2 
200 
2 
2 
650 
20 
20 
1,000 
35 
54 
1,000 
12 
14 
100 
38 
27 
80 
19 
46 
100 
56 
157 
98 
110 
180 
116 
176 
75 
75 
Per cent 
of 
injury. 
0.1 
0.9 
1.25 
1.2 
LO 
3.0 
5.4 
1.4 
27.0 
98.0 
57.5 
56.0 
70.0 
97.2 
100.0 
A second table shows the percentage of infestation at a number of 
other localities during the latter part of the season. It includes data 
for localities representing practicall}^ the entire cotton belt, showing 
an average percentage of infestation of Y8.3. The difference between 
the early and late corn is plainly seen, averaging only 78 per cent for 
a number of cases of the former and 98 per cent for the latter. 
