Data from: Male and female age affects the reproductive potential of two tephritid flies

In insects, aging produces deterioration in physiological and cellular
functioning, affecting their reproductive potential. Anastrepha
fraterculus and Ceratitis capitata are two
fruit fly species where overwintering adults resume their reproductive
activity in spring, giving old individuals the possibility of mating with
young adults. Most age studies focus on male reproductive capacity;
however, we lack information on how the interaction between the ages of
both sexes can determine post-mating processes. Here, we studied sex and
age effects on (i) female fecundity and fertility, (ii) failure to leave
viable offspring (reproductive failure), and (iii) female remating
behavior. We found that young pairs of both species had higher fecundity,
but young C. capitata males mated with old females had
the lowest fecundity. This suggests that overwintering flies in this
species will not substantially contribute to the next generation. We also
found in C. capitata more prevalent reproductive failure
in hetero-age combinations, which could be due to age recognition between
mates, resulting perhaps in differential ejaculate allocation. Copula
duration was positively associated with female age, yet it was longer for
older A. fraterculus females and shorter
for C. capitata females. Female remating was lower when
young females mated with old males in C. capitata. This would
imply that males perceive young females of “good quality” and thus invest
and transfer all the ejaculate possible to ensure the delay of renewal of
female receptivity. Aging does not always cause a decline in reproductive
potential, which may be important in species that overwinter as adults.
Complex interactions between female physiology and male ejaculate
senescence can impact postcopulatory behaviors that affect reproductive
success for both sexes.