Table 1 shows the number of sires, records and mean values for egg number and weight for the 16 crosses in our study.
Conversely, decreases in the weight loss by mothers entailed a negative association between mean egg mass and nymph number (Table 2A, Figure 2C).
In particular, low maternal expenditure on egg care led to a negative association between mean egg mass and nymph number, as well as weakened positive association between egg and nymph numbers.
Two Generalized Linear Models (GLM) were then used to test whether egg number, mean egg mass, relative weight loss by mothers and their interactions influenced the number and the mean weight of nymphs at hatching.
Overall, there was no association between egg number, mean egg mass and the relative weight loss by mothers during the period of egg care (Table 1A).
A series of pairwise interactions among egg number, mean egg mass and female weight loss determined the number of hatched nymphs (Table 2A), a result supporting the entangled effects of maternal expenditure on egg care and egg production on nymph production.
Although heavy or large eggs are known to need more time to develop across species [ 9], we found that egg developmental time was independent of mean egg mass, of the number of eggs or of female expenditure on egg care (Table 1A and 1B).
Independent of these effects on nymph number, our data showed that (4) the mean weight of nymphs at hatching was positively associated with the mean egg mass, but independent from egg number and investment into pre-hatching care.
Covariates tested included development time in GLMMs for adult mass and wing traits and mean egg size, female longevity and egg number in GLMMs for fecundity.
Reproductive output of the 36 females was assessed by means of daily fecundity (egg number for days 1 to 10 of oviposition), and egg size (for a random subsample of eggs from days 2, 4, 6, 8, and 10 of oviposition).
