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The age and mating sequence of male and copula- tion chances of
female Tetranychus urticae are not significantly effecting the
oviposition period, longevity, egg-hatching and reproductive
rates of female. Daily and total reproduction of mated females
are significantly higher than that of virgin females;
copulation chances and sequences of female did not influence
its reproductivity. Upon insemination, sperms and accessory
materials transferred by males may be able to enhance the egg
maturity and rates of egg deposition of the female. Sex ratio
of twospotted spider mite is controlled by parental male-age at
insemination. Virgin females mated with either one of 1, 4, 7,
and 10 days old vir- gin male or the males after different
mating chances (1-4). The female sex ratios (female/(female +
male)) of offspring are higher in these mating with younger age
males and earlier sequence of mating pairs. The maximum daily
sex ratio of progeny occurred on the second or third day after
female copulation, but was not correlated with mating age of
male or female or copulation times of females. "Effective
mating" is defined here as numbers or frequencies of mated
female produce female offspring to evaluate the variation of
ability of male to insem- inate the females. The"effective
mating" varied with 1-day virgin female mating pairs of either
1, 4, 7, or 10-day old virgin male to produce 12.96, 9.73,
8.50, and 4.57 "effective mating", respectively. Total female
progeny reproduced in her life span decreased with male age of
her mating pair. In conclusion, the first mating of female two-
spotted spider mite is the only "effective mating". The
significance of male in the population includes the incremental
effects of reproductive potential on females and sex ratio in
the female progeny. Conse- quently, the "ineffective mating" of
the second or higher sequences in mating of female is
extrapolated by the functions of "mating plug", "antagonism",
and/or "rejection".
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