Experiment 2 
Experiment 2 was a comparison of H. zea oviposition and 
larval count records in a trapped and an untrapped field utiliz- 
ing chemical control versus no chemical control. 
Design 
The experiment was conducted near the southern end of the 
12- by 35-mile area. Large fields about one-half mile apart were 
chosen for the study (fig. 3). Two farmers, Frazier and Leigh, 
each agreed to furnish 40 acres of cotton. Each 40-acre field 
was divided into eight 5-acre plots. Four plots in alternate 
positions received no insecticide; the other four plots were 
treated with insecticides when the farmer treated the remainder 
of his field. Farmers notified the writer in advance of each 
application of insecticide so that he could observe the procedure. 
Counts of oviposition, larvae, and boll damage were made through- 
out the season, 
Collecting Data 
Oviposition and larval counts were taken in both fields at 
about 3-day intervals. A total of six 25-plant samples (three 
per man) were taken from randomly selected areas in each 5S-acre 
block, 
Damage counts were taken by randomly selecting 25 single 
plants per sample. Two samples were taken in each of the eight 
plots per field after insecticide applications began; sampling 
continued at irregular intervals throughout the season. Numbers 
of bolls, blooms, and squares and the injury to each fruiting 
form were recorded. The final boll damage count was taken by 
randomly selecting three 1/2000-acre samples for each treated 
and untreated plot. 
Results 
Figure 3, though not drawn to scale, indicates fairly 
accurately the trapped and untrapped cotton fields in the area. 
