Abstract: 【Aim】This study aims to determine the hatching rates and hatching duration of Coccinella septempunctata, Harmonia axyridis and Propylaea japonica eggs stored under different temperatures for different duration, so as to explore the optimal storage temperature and duration of the three commoditized ladybird eggs.【Methods】After the newly laid eggs of C. septempunctata, H. axyridis and P. japonica were maintained under 6, 8 and 10 ℃ for 3, 5, 7, 9, 11, 13 and 15 d, the hatching rates were determined. The newly laid eggs of C. septempunctata, H. axyridis and P. japonica were placed at 15, 20 and 25 ℃, and the egg hatching duration was tested. 【Results】The hatching rates of C. septempunctata eggs stored under 6, 8 and 10 ℃ within 5 d were higher than 80%. The hatching rates of C. septempunctata eggs stored under 6, 8 and 10 ℃ for more than 5 d showed significant difference, and their hatching rate under 10 ℃ was the highest. The hatching rate of C. septempunctata eggs stored under 10 ℃ for 11 d was 56.1%. H.axyridis eggs were more sensitive to low temperatures. When H.axyridis eggs were stored under 10 ℃ for 7 d, the hatching rate was 85.3%, while that of H. axyridis eggs stored under 6 ℃ for 7 d was only 6.1%. When H. axyridis eggs were stored under 10 ℃ within 11 d, the hatching rate was not less than 50%. P. japonica eggs were the most sensitive to low temperatures. The hatching rate of P. japonica eggs was decreased to 34.3% when stored under 10 ℃ for 7 d and decreased to 0 when stored under 6 and 8 ℃ for 3 d. The egg hatching duration of the three ladybird species increased with the decrease of incubation temperature. The egg hatching duration of the three ladybird species was 7-8, 4-5 and 2-3 d, respectively, under 15, 20 and 25 ℃. 【Conclusion】The optimial storage temperature is 10 ℃ for C. septempunctata and H. axyridis eggs, and their hatching rates are higher than 85% when stored under 10 ℃ within 7 d. Cold storage is not applicable for P. japonica eggs. The shelf life of ladybird eggs can be extended by reducing the incubation temperature to 15 ℃.

Key words: Coccinella septempunctata, Harmonia axyridis, Propylaea japonica, ladybird eggs, cold storage temperature, cold storage duration, incubation temperature, hatching rate