Intra- and inter-specific predation of eggs is well documented in aphidophagous ladybird beetles. Chemical defenses of eggs of Asia-originated invasive Harmonia axyridis is the possible reason for population declines of native ladybirds in North America and Europe. However, this supposition cannot be confirmed without determining whether H. axyridis eggs are toxic to native ladybirds in its original areas. To investigate mechanisms responsible for H. axyridis invasion, we conducted a feeding experiment to examine neonate developmental performance of three sympatric ladybird beetles, Propylea japonica, Coccinella septempunctata, and H. axyridis, which fed on aphids (control), conspecific or heterospecific eggs. The results indicated that H. axyridis eggs were lethal or sub-lethal to P. japonica and C. septempunctata neonate larvae, whereas the reverse was not the case. Survival from the 1^st to the 2^nd instar stage in P. japonica was almost seven-fold higher when feeding on conspecific and C. septempunctata eggs than on H. axyridis eggs. C. septempunctata neonates did not survive to the next instar when feeding on H. axyridis eggs, whereas over 85% survived when feeding on other types of food. In contrast, survival of H. axyridis neonates to the next instar was over 90% when feeding on either conspecific or heterospecific eggs. Although P. japonica and C. septempunctata neonate developmental duration to the next instar was prolonged when feeding on heterospecific as opposed to conspecific eggs, H. axyridis neonates did not exhibit the difference between feeding heterospecific and conspecific eggs. Both P. japonica and H. axyridis neonate larvae ended up with body weight gain at molting into the 2^nd instar as same when feeding on conspecific eggs as when feeding on heterospecific eggs, whereas C. septempunctata neonate larvae decreased body weight gain when feeding on P. japonica eggs as compared to feeding on conspecific eggs. Our study results suggest that H. axyridis eggs are toxic to both C. septempunctata and P. japonica neonate larvae, but the reverse is not true, thereby not confirming the supposition that chemical defense of H. axyridis eggs is a potential factor for population declines of native ladybirds in North America and Europe.