关键词: 龟纹瓢虫, 人工饲料, 正交实验法, 生长发育, 生殖力, 能源物质

Abstract: 【Aim】 The aim of this study is to screen the optimal ratio of artificial diet for Propylaea japonica and evaluate the feeding effect of the optimized artificial diet. 【Methods】 Fresh pork liver, honey, sucrose, yeast powder, olive oil and sorbic acid were used as the basic diet ingredients. An orthogonal experimental design was employed to assess the impacts of artificial diet added with varying ratios of rape pollen, cholesterol and vitamin E on several developmental parameters, including developmental duration, eclosion rate, adult acquisition rate, sex ratio (proportion of females), and female and male adult weight of P. japonica. Additionally, the effects of the optimized diet formula on the developmental duration, number of eggs laid per female and ovarian development of P. japonica, as well as the fat, total sugar and total protein contents in the 6-day-old adults were examined. 【Results】 A 20% inclusion of rape pollen in the artificial diet significantly increased the body weight of both female and male adults of P. japonica, the addition of 0.4% cholesterol yielded the most favorable outcomes, and the addition of 1.6% vitamin E resulted in the optimal proportion of females of P. japonica. The optimized artificial diet formula consisted of 20 g of fresh pig liver, 4 g of honey, 4 g of sucrose, 1 g of yeast powder, 0.06 mL of olive oil, 0.1 g of sorbic acid, 4 g of rape pollen, 0.08 g of cholesterol and 0.32 g of vitamin E. Compared to rearing with A. pisum nymphs, rearing with the optimized artificial diet did not significantly affect the survival rate or eclosion rate of P. japonica. However, when P. japonica was fed with the optimized artificial diet, the larval duration was extended by 40.8%, the pupal duration prolonged by 21.9%, and the female and male weight decreased by 34.1% and 30.7%, respectively, the adult acquisition rate increased significantly by 20.1%, the pre-oviposition period extended by 38.9% and the number of eggs laid per female reduced by 71.1%, as compared with those fed with A. pisum nymphs. However, when P. japonica was fed with the optimized artificial diet at the larval stage and with A. pisum nymphs at the adult stage, there was no significant change in the pre-oviposition period, and the number of eggs laid per female only decreased by 46.3%, as compared with those fed with A. pisum nymphs. Additionally, compared with feeding on A. pisum nymphs, larval feeding on the optimized artificial diet led to delayed ovarian development, significant reduction in ovarian length, increased fat content, decreased total protein content, and no significant change in total sugar content in the 6-day-old female adults of P. japonica. 【Conclusion】 The artificial diet optimized through orthogonal experiments is suitable for rearing P. japonica larvae. Compared to rearing with A. pisum nymphs, rearing with the optimized artificial diet caused no significant changes in larval survival rate and adult eclosion rate of P. japonica, but increased the pupal weight, improved the adult acquisition rate and prolonged the larval duration. Further refinements are necessary to enhance the overall effectiveness of this optimized diet.

Key words: Propylaea japonica, artificial diet, orthogonal experimental method, growth and development, fecundity, energy materials