中华通草蛉成虫抗寒能力季节性变化

中华通草蛉（Chrysoperla sinica）成虫在自然条件下抗寒能力的季节性变化研究表明,雌、雄成虫的抗寒能力均呈现出季节性的变化趋势,即随着冬季低温的到来,其抗寒能力逐渐增强,冬季过后又随气温的回升,其抗寒力逐渐减弱.雌、雄成虫的体内含水量、过冷却点（SCP）和结冰点（FP）均随气温的降低而降低,升高而升高,但体内总脂肪的含量却随气温的降低而升高,升高而降低.越冬代在越冬的前期和中期,雌、雄成虫体内的含水量和SCP均显著低于生长季节的其它各代,越冬代后期的含水量和SCP与生长季节其它各代没有显著差异.经回归分析发现,雌、雄成虫体内含水量与SCP之间均存在极显著负相关关系（p＜0.01）;越冬代成虫（特别是越冬前期）的体内总脂肪含量显著高于其它时期,并且雌成虫体内的总脂肪含量与SCP之间呈显著正相关（p＜0.05）,雄成虫体内总脂肪含量与SCP之间没有显著相关性（p＞0.05）.在一年的不同世代中,雌、雄成虫体内含水量只是在越冬前期有显著差异,SCP和体内总脂肪含量却在越冬后期有显著差异.

Seasonal changes of cold hardiness of the green lacewing, Chrysoperla sinica (Tjeder) (Neuroptera: Chrysopidae)

The green lacewing,Chrysoperla sinica (Tjeder),a common species in China,is known as an important natural enemy attacking many kinds of agricultural and forestry pests.It is one of the important dominant natural enemies in Tai'an of Shandong Province.Under natural conditions, it has four generations and obvious metagenesis during the whole year,and overwinters in adults of the fourth generation in facultative diapause.In the present study, experiments were carried out to examine the capability of the adult cold hardiness among the different generations,especially the seasonal changes of the water and fat content in adult body and the supercooling point (SCP) were determined.Results showed that the cold hardiness of the female and male adults took on seasonal changes that the cold hardiness gradually strengthened with the winter temperature decreasing and weakened with the temperature increasing after winter.The water and fat content,the SCP and freezing point (FP) of the female and male adults changed greatly among the generations in the different seasons.The water content and SCP of the overwintering female and male adults during the pre- and mid-overwintering period were significantly lower than that of other generations in growing seasons,but the water content and SCP had no difference between the adults during the late overwintering period and other generations in growing seasons.The regression analysis showed that there was remarkably negative correlation between the water content and SCP of the adults (p<0.01).The total fat content of the overwintering generation (especially at the pre-overwintering period) was significantly higher than that of other generations,and the correlation between the total fat content and SCP was significantly positive in female adults (p<0.05),otherwise,there was no correlation in male adults(p>0.05).Compared the female adults with the male adults in the different generations,the water content had significant difference only in the pre-overwintering period,and the SCP and the total fat content had significant difference only in the late overwintering period.