DESERT 
DESERT 
(SEARS) 
BY 
SULLIVAN DESERT 
DESERT 
WHA HOMEMADE 
= LETHALITES 
DESERT ene 
UNLIGHTED 
? 
UNLIGHTED 
10 
DESERT 
DESERT 
Figure 1.--Features of the area in which seasonal oviposition 
records for H. zea were taken from one untrapped and three 
trapped fields. Numerals in fields refer to the number of 
insecticide applications in the 1965 season. Drawing is 
not to™seaile, 
Collecting Data 
Two men starting at different locations in a field each made 
ten 25-plant sample counts to determine and record numbers of 
H. zea eggs and larvae present. Early in the season counts were 
taken on the entire plant. Later, only terminals of the plants 
were considered in the counting procedure. 
Results 
The results of egg counts are shown in. figure 2. Arrows in 
the illustration pointing toward the X coordinate indicate the 
dates of insecticide applications. Arrow shafts were drawn in 
the same legend as was used to represent the egg count in a given 
field. Insecticide applications per study field are shown in 
figure 1. Although the field with the Lethalite installation 
