Physiological And Biochemical Mechanisms Of Adult Overwintering And Diapause Of Chrysoperla Sinica (Tjeder)

The lacewing, Chrysoperla sinica (Tjeder), is an important natural enemy attacking agricultural and forestry pests like aphids, mites and eggs, young larvae of lepidopterous insects, and a good biological control agent. This species overwinters as diapausing adults. This paper mainly dealt in details with biochemical mechanisms of adult diapause and cold hardiness in natural and experimental conditions. The main results were summarized as follows.1. Cold hardiness ability of the different developmental period of Chrysoperla sinica The SCP and FP of the different development period of Chrysoperla sinica was investigated. The results indicated that the SCP and FP of diapausing adults was the lowest, which were–17.04±2.89℃and–11.75±2.95℃and the SCP and FP of prepupa was the highest, which were–10.08±3.24℃and–4.19±1.36℃during the SCP and FP of the different development period.Comparative experiment of cold hardiness ability between diapausing adults and non-diapasuing adults of Chrysoperla sinica under laboratory conditions indicated that the cold hardiness ability of diapausing adults was significantly higher than that of non-diapausing adults except the fresh emerged adults.The regression analysis showed that there was not remarkably correlation between the fresh weight and SCP of the adults (P>0.05),but it didn't indicated it was not correlation with the cold hardiness ability.2. Seasonal changes of cold hardiness of Chrysoperla sinica Experiments were conducted to examine the capability of the adult cold hardiness among the different generations,and the seasonal changes of the water and fat content in adult body were determined.Results showed that the cold hardiness of the female and male adults changed seasonally,that it gradually strengthened with the winter temperature decreasing and weakened with the temperature increasing after winter.The water and fat...