Functional response of Harmonia axyridis preying on Acyrthosiphon pisum nymphs: the effect of temperature.

In the current study, we investigated the functional response of Harmonia axyridis adults and larvae foraging on Acyrthosiphon pisum nymphs at temperatures between 15 and 35 °C. Logistic regression and Roger's random predator models were employed to determine the type and parameters of the functional response. Harmonia axyridis larvae and adults exhibited Type II functional responses to A. pisum, and warming increased both the predation activity and host aphid control mortality. Female and 4th instar H. axyridis consumed the most aphids. For fourth instar larvae and female H. axyridis adults, the successful attack rates were 0.23 ± 0.014 h-1 and 0.25 ± 0.015 h-1; the handling times were 0.13 ± 0.005 h and 0.16 ± 0.004 h; and the estimated maximum predation rates were 181.28 ± 14.54 and 153.85 ± 4.06, respectively. These findings accentuate the high performance of 4th instar and female H. axyridis and the role of temperature in their efficiency. Further, we discussed such temperature-driven shifts in predation and prey mortality concerning prey-predator foraging interactions towards biological control.

Technology Optimization of Supercritical CO2 Extraction from Zingiberis rhizoma / 中国药房

OBJECTIVE:To optimize the technology of supercritical CO2 extraction from Zingiberis rhizoma. METHODS:With the comprehensive score of the contents of 6-ginger phenol,8-ginger phenol and 10-ginger phenol and the extraction rate of the oil from Z. rhizoma as the index,uniform design method was adopted to investigate the effects of extraction pressure,extrac-tion temperature and extraction duration on the extraction result;verification tests were conducted. RESULTS:The optimal condi-tions were as follows as the extraction pressure of 25 MPa,extraction temperature of 30 ℃ and extraction duration of 2 h. In the verification tests,the average extraction rate of the oil from Z. rhizoma was 3.2%(n=3),and the comprehensive score was 1.874 2 (RSD=0.65%,n=3),with the relative deviation of 0.6% between the measured value and the predicted value. CONCLUSIONS:The optimal extraction technology is stable and feasible,with the advantages of low temperature,short duration.