Effect of egg size variation on survival rate, development and fecundity of offspring in a migrant skipper, Parnara guttata guttata (Lepidoptera : Hesperiidae)

Life history traits of Parnara guttata guttata hatched from large-sized and small-sized eggs were compared. Eggs were grouped into two sizes, larger than 0.19mm^3 (L group) and smaller than 0.16mm^3 (S group). Larvae from these groups were reared individually under a 16L8D photoperiod at 25℃. The survival rate in immature stages was significantly higher in the L group than the S group. Although not significant, the developmental time during immature stages of the L group was shorter than that of the S group. Notably, the pupal period was shortened significantly in the former group. The fecundity of female adults from the L group was higher, but not significantly so. Female adults in the L group laid significantly larger eggs than those in the S group. Phenotypic correlations between egg size and other traits were generally negligible. However, the correlation between the fecundity of females in the L group and the size of eggs they laid was significantly negative. These results suggest that egg size variation under fixed conditions affect fitness of offspring in P. g. guttata.