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Psyche 
[Vol. 87 
from 5 min to 14 d (Mitchell and Mau, 1969; Harris and Todd, 
1980a). Frequently, females remate immediately after the termina¬ 
tion of one copulation, but the time between copulations is variable 
(Harris and Todd, 1980a). The resulting pattern of sperm prece¬ 
dence is atypical for insects because the sperm of the first male to 
mate the female predominates in the fertilization of the first 2 egg 
masses following remating, after which the second male gains 
precedence (McLain, 1981). Egg masses containing 60-120 eggs are 
laid approximately weekly throughout the 2 month life of the 
female. A single insemination provides sufficient sperm for fertiliza¬ 
tion of all the eggs a female produces. 
Male N. viridula produce a pheromone which attracts females, 
other males, and the tachinid parasitoid (Harris and Todd, 1980b; 
Mitchell and Mau, 1971). Parasitoidization by T. pennipes greatly 
reduces N. viridula fitness. The lifetime of the parasitoidized stink 
bug is reduced by greater than 50% and fecundity, number of eggs 
per mass, by 40-47% (Shahjahan, 1968). 
Methods 
Two experiments were conducted to determine if the duration of 
copulation influences male fertilization success. First, 16 yellow 
colored females were mated in succession to a green male and then 
to a yellow male. Yellow color is inherited as a simple mendelian 
recessive trait. Eggs fertilized by yellow males produce red nymphs 
while eggs fertilized by green males produce black nymphs. Second, 
16 yellow females were mated 3 times. Either the first 2 matings were 
performed by green males or the last 2 by yellow males. This 
experiment would simulate prolonged copulation if the amount of 
sperm transferred correlates with the duration of copulation. 
Yellow N. viridula were provided by Dr. R. 1. Sailer from a 
labortory stock while green adults were the first laboratory gener¬ 
ation of field collected adults. 
Previous work indicated that the sperm from yellow and green 
males is equally competitive (McLain, 1981). Therefore, it was not 
necessary to alternate between the color type of the male inseminat¬ 
ing the female first as a control measure. And, employing a green 
male first would allow detection of males which contained a 
recessive color allele by inspecting the progeny from eggs laid prior 
to the second and third matings. This procedure was preferred since 
