1980] 
McLain — Nezara viridula 
327 
several rare yellow morphs have recently been discovered in Tifton, 
Ga not far from Cordele where the present stock was collected (V. 
Harris, personal comm.). 
The sperm precedence experiments employed 7-10 day old virgin 
males and females. Single females were placed in mason jars with 5 
males until mating had begun. The mating pair was removed to a 
separate jar. Upon termination of mating the sequence was repeated. 
All bugs were fed fresh green beans. A 16L:8D photophase was 
used. 
The impact of the social environment on the duration of 
copulation was assessed by determining the duration of copulation 
for stink bugs exposed to 2 different sex ratios. Jars housed either 4 
males and 2 females (n = 79) or, 2 males and 4 females (n = 40). 
Upon mating, pairs were isolated into separate jars. Pairs were 
checked 3 times daily, during the 1st, 9th, and 16th hours of the 16h 
photophase. This routine is sufficient to record the great majority of 
matings since the duration of copulation is rarely less than 8 h 
(Harris and Todd, 1980a). 
Once matings had terminated, females were isolated and oviposi- 
tion recorded. The number of fertilized eggs and the hatching 
percentage were recorded. The size of the mating male was also 
recorded. 
During field collections the number of parasitoid eggs on mating 
and non-mating males was recorded. The maximum width of the 
pronotum was also measured, using a hand held ruler. This was to 
determine if larger males suffered greater levels of parasitoidization. 
Pronotal width correlates well with male dry weight (r 2 = .62). 
To determine if females risk parasitoidization by T. pennipes 
while mating, non-mating females were collected on 5 occasions in 
August, 1980 from 2 abandoned 5 hectares snap bean fields in 
Cordele, Ga. The number of parasitoid eggs on each female was 
recorded. Females were taken to the laboratory and placed singly in 
mason jars with fresh green beans. Oviposition during the 10 days 
following collection was recorded. 
Results 
The duration of the 1st copulation of females multiply-insemi¬ 
nated correlated with the fertilization success of the males. When the 
duration of the first copulation was greater than 3.67 d, the first 
