Offspring emergence and subsequent survival
During the 50-day pupal observation period, 96% of 355 pupae from the
control, 93% of 187 pupae from the mating delay, and 91% of 232 pupae
from the nutritional stress group emerged successfully. There was no
evidence of variation in the probability of emergence between pupae from
different mothers across treatments and no convincing evidence of an
effect of pupal wet weight or mother age on the probability of emergence
for pupae from the control or mating delay groups (null models: controlω = 0.612; mating delay ω = 0.492) (Table S4.10). However,
there was evidence of an effect of both wet weight and mother age for
the nutritional stress group (model with weight and age ω =
0.602). Pupae in the nutritional stress group from older mothers had a
lower probability of emergence and this was exacerbated for pupae in the
lowest weight quartile (Fig. S7, Table S4.11).
All starved offspring were dead by 15 days post emergence. There was
only evidence for an effect of individual mother on survival in the
nutritional stress group (model including random intercept: controlω = 0.347; mating delay ω = 0.287; nutritional stressω = 0.916) (Table S4.12). Although there was no evidence for a
difference in wet weight between female and male offspring (Fig. 5a),
across all three treatments there was evidence that on average female
offspring survived slightly longer than males (Table S4.13, Fig. 5b).
For all three treatment groups, there was a quadratic effect of mother
age on offspring survival and offspring from young mothers in the
nutritionally stressed group were particularly vulnerable to early
starvation (Fig. 5b, Table S4.12 – 14).