Abstract:
Trade-offs between life-history traits offset the energetic costs of maintaining fitness in
complex environments. Ceratitis species have been recorded to have long lifespans,
which may have evolved in response to seasonal resource fluctuation. It is thus likely that
reproductive patterns have evolved concomitantly as part of the trade-off between lifespan
and reproduction. In this study, we investigated how reproductive patterns differ between
Ceratitis cosyra (Walker) and Ceratitis capitata (Wiedemann; Diptera: Tephritidae), two
species with different average and maximum lifespans. Females of both species were
mated and patterns of female survival, fecundity, remating and sperm storage were tested.
Ceratitis cosyra had a higher rate of survival and a lower fecundity when compared with
the shorter-lived C. capitata, suggesting that both species exhibit a trade-off between
lifespan and reproduction. Both species showed a similar and consistent willingness to
remate, despite declines in sperm storage, suggesting that sperm alone does not fully
inhibit remating. As expected, C. cosyra transferred high numbers of sperm during the
first mating. However, sperm stores declined unexpectedly by 14days. This indicates that
males might transfer large ejaculates as a nuptial gift, that females then later degrade as
a source of nutrients. Large declines in sperm storage may also indicate that females
discard excess sperm stores due to the toxicity involved with storing sperm. These results
do not suggest that patterns of sperm storage and remating align with lifespan and
resource seasonality in these species, but a wider range of species needs to be assessed
to better understand variation in Ceratitis mating systems.
