Effects of Low Temperature Treatment on Storage and Hatchability of Eggs of Dastarcus helophoroides

CHEN Yuansheng; CHEN Shengkui; YU Haiping; LUO Zhidi; LIU Xingping

doi:10.15933/j.cnki.1004-3268.2018.01.013

Abstract：In order to determine the influence of storage temperature,storage time and incubation temperature on hatchability of Dastarcus helophoroides eggs,the hatchability of the eggs was studied by cryopreservation at 5,7.5,10,12.5,15 ℃ and incubation at 20,26,32 ℃.The results showed that the low temperature of 5 ℃ was not suitable for preserving the eggs of Dastarcus helophoroides,because it caused the hatching rate to decrease significantly (P ＜ 0.05).Other low temperatures of 7.5-15 ℃could be used to preserve the eggs,preservation within 70 days would not reduce egg viability,and there was no obvious difference between the hatchability of these tests and the control (no hypothermia treatment).Storage time had no significant effect on egg hatching rate within 70 days(P ＞ 0.05).The incubation temperature also had significant influence on the hatching rate of the eggs,stored at the same low temperature,the hatching rate of the eggs under the condition of 20 ℃ was the highest,which showed significant difference from the hatchability under 26 ℃ and 32 ℃ (P ＜ 0.05).The period of hatching peak was the eighth day to the twelfth day under 20 ℃,and that of 26 ℃ was the seventh day to the eleventh day,and that of 32 ℃ was the fifth day to the eighth day.The hatching time of eggs was highly significantly correlated with the hatching rate on the same day (P ＜ 0.01),and the hatchability in the morning was significantly higher than that in the noon and evening.In conclusion,the optimum storage temperature for the eggs of Dastarcus helophoroides was 10 ℃,the optimum incubation temperature was 20 ℃,and the storage time should be within 70 days.Under these conditions,the hatching period was the fifth day to the fourteenth day,and the peak hatching period was the eighth day to the twelfth day,that was to say,the egg card should be released to forest at the fifth to the eighth days after being taken out from low temperature.The egg cards should be released at an average temperature of 20 ℃ in the field,when the hatching rate and parasitism rate of eggs were the highest.