1980] 
McLain — Nezara viridula 
329 
2 3 4 5 6 7 
COPULATION DURATION CD) 
Figure 2. Distribution of mating duration in jars with 4 males and 2 females or 2 
males and 4 females. In jars with 4 males and 2 females the proportion of matings 
greater than the modal duration of 2 d was significantly greater than the proportion 
in jars with 2 males and 4 females (P<.05, t=2.5; t-test). 
.0001; t > 5.5). Females in the field also tended to mate with larger 
males (Fig. 3; Table 1). Thus, field and laboratory data indicate that 
females mate non-randomly with respect to male size. 
In the field females might appear to mate non-randomly with 
respect to size if the duration of copulation were longer for larger 
males. However, laboratory data suggest that the duration of 
copulation was not dependent upon male size (Table 1). 
Females which mated larger males enjoyed a greater percentage 
hatching of their fertilized eggs than did females which mated small 
males (Table 1); This analysis was limited to the second egg mass 
since the first one often failed to hatch and because failure of 
hatching in later egg masses might have reflected declining female 
vigor. 
It would be premature to attribute non-random mating solely to 
female preference. Data collected from jars with 4 males and 2 
females indicated that larger males were more viable. Therefore, 
they may have been more persistent in their mating attempts, more 
vigorous in intermale aggression, or capable of a more copious 
