Abstract: 【Aim】 Egg cannibalism is common in predatory Coccinellidae. It is generally held that consumption of sibling eggs is critical to neonate larvae, but the nutritional value of non-sibling eggs cannibalized relative to prey aphids is still under debate. This study aims to examine the effect of feeding non-sibling eggs besides aphids in larval stage on the reproductive performance of female adults of Harmonia axyridis. 【Methods】Three diet treatments were set at larval stage of H. axyridis: the control (CK) with Rhopalosiphum padi aphids provided only, the dispersive egg consumption (DEC) treatment with non-sibling eggs provided in a small amount to ladybird larvae of each instar, and the aggregative egg consumption (AEC) treatment with non-sibling eggs provided in a large amount only to the final instar larvae as supplementary food together with R. padi aphids provided in the whole larval stage. The ladybird larvae with the above treatments were followed to adulthood, and the body volume of female adults, pre-oviposition period, 10-day fecundity, and egg hatching rate were surveyed. 【Results】 The diet treatment had no significant effect on the body volume of female adults of H. axyridis, which was 92.30, 89.73 and 93.98 mm³ in treatments CK, DEC and AEC, respectively. The diet treatment also had no significant effect on the pre-oviposition period, which was 7.50, 7.74 and 7.70 d in CK, DEC and AEC, respectively. The diet treatment, however, had a significant effect on 10-day fecundity. Female adults in AEC laid much fewer eggs (88) than in DEC (185) and CK (205) during the first 10 d after emergence, and no significant difference was found between DEC and CK. The diet treatment had no significant effect on egg hatching rate, which was 63.10%, 72.58% and 66.61% in CK, DEC and AEC, respectively. 【Conclusion】 These results suggest that consumption of a few non-sibling eggs across larval instars has negligible effects on reproductive performance of H. axyridis adults, but consuming a large number of non-sibling eggs at the final instar can considerably decrease its female adult fecundity.

Key words: Harmonia axyridis; intraspecific predation, reproduction, body size, egg hatching rate