The seasonal larval counts for both fields are shown in 
figure 5. Again, the light traps appeared to be as effective as 
the 10 applications of insecticide in controlling populations of 
H. zea under the conditions of this experiment. Larval counts in 
the insecticide treated plots compared with those from untreated 
plots in the untrapped field show that nothing kept the bollworm 
population on the untreated plots under control. Early in 
August, the number of larvae per 100 terminals on the untreated, 
untrapped plots averaged slightly more than 30; most of the 
larvae were fifth and sixth instar. These large larvae had eaten 
practically all the fruit and were actually chewing the terminal 
4 to 6 inches of the plant. 
ee ee 
50 
40 
UNLIGHTED, INSECTICIDE 
30 /\ ———— UNLIGHTED, NO INSECTICIDE 
LIX —o— LIGHTED, NO INSECTICIDE 
ZEA LARVAE PER 100 TERMINALS 
H. 
ne) 20 Sil He) 20 S| 10 20 
JULY AUGUST SEPTEMBER 
Figure 5.--Larval records from trapped vs. untrapped and 
from treated vs. untreated plots of cotton. 
Table 1 shows the damage counts taken during August and 
September. The initial counts were made to establish differences 
in control between treated and untreated plots within a given 
field. Thus, no counts were taken in the trapped field because 
no insecticides had been applied. The changes in percentage of 
damage to each type of fruiting form from time to time are 
interesting. However, little meaningful data can be abstracted 
from bloom and square damage counts after the season is over. 
Probably the most useful data in the table pertain to the numbers 
of bolls and the percentage of damage to these bolls recorded at 
each inspection date. 
10 
