溴氰虫酰胺对双委夜蛾生长发育、繁殖和营养利用的影响

【目的】研究低剂量的溴氰虫酰胺对双委夜蛾(Athetis dissimilis)生长发育、繁殖和营养利用的影响,明确溴氰虫酰胺对双委夜蛾的控制作用。【方法】采用人工饲料混毒法测定溴氰虫酰胺对双委夜蛾4龄幼虫的毒力;利用LC_5、LC_(25)和LC_(50)剂量的溴氰虫酰胺处理双委夜蛾4龄幼虫,观察其对亲代幼虫和蛹的发育历期、成虫寿命、产卵量、化蛹率和羽化率等生长发育指标的影响;测定溴氰虫酰胺处理72 h后对幼虫的近似消化率(AD)、相对取食量(RCR)、相对生长量(RGR)、摄入食物转化效率(ECI)、消化食物转化效率(ECD)等营养利用指数的影响;分析溴氰虫酰胺处理24、48和72 h后幼虫体内糖类、蛋白质和脂质含量的变化。【结果】溴氰虫酰胺对双委夜蛾4龄幼虫具有较高毒力,LC_5、LC_(25)和LC_(50)分别为0.13、0.34和0.66μg·g~(-1)混毒饲料;与对照组相比,LC_5、LC_(25)和LC_(50)剂量下双委夜蛾4—6龄幼虫的发育历期分别延长了1.63、1.75和5.48 d,同时蛹的发育历期延长,雌雄成虫的寿命缩短,并显著降低了双委夜蛾幼虫的化蛹率和蛹的羽化率,LC_5、LC_(25)和LC_(50)处理组雌蛹重分别为130.2、127.8和127.5 mg,显著低于对照组的蛹重(146.7 mg),但是对雄蛹重无显著影响。溴氰虫酰胺处理后,LC_5、LC_(25)和LC_(50)组的单雌产卵量分别为558.8、506.9和462.8粒,显著低于对照组(755.1粒)。同时,溴氰虫酰胺处理组缩短了成虫的产卵历期,但是对成虫产卵前期的影响不明显。此外,与对照组相比,LC_5、LC_(25)和LC_(50)剂量的溴氰虫酰胺显著降低了双委夜蛾4龄幼虫的RGR、RCR、ECI和ECD,降低了幼虫将食物转化为生物量的能力;溴氰虫酰胺处理双委夜蛾4龄幼虫24 h后显著降低了其体内碳水化合物的含量,而且这种不利影响持续到48 h和72 h,同时,溴氰虫酰胺处理也显著降低了4龄幼虫体内脂质和蛋白质的含量,阻碍了双委夜蛾幼虫正常的生长发育和繁殖。【结论】较低致死剂量的溴氰虫酰胺可以抑制双委夜蛾种群的生长发育和繁殖,有利于长期有效控制双委夜蛾的发生。

Effects of Cyantraniliprole on Development,Fecundity and Nutritional Utilization of Athetis dissimilis

【Objective】In order to clarify the control effect of cyantraniliprole on Athetis dissimilis, the effects of cyantraniliprole at low-lethal dosages on the growth, reproduction and nutritional utilization were studied after treated the 4th instar larvae of A. dissimilis. 【Method】The toxicity, as well as the nutritional utilization and the content of biochemical substances of cyantraniliprole on the 4th instar larvae of A. dissimilis were determined by using the method of artificial diet mixed with insecticides. The sublethal effects of cyantraniliprole on growth and development index: developmental time of larvae and pupae, mean longevity of adults, fecundity of females, the rate of pupation and eclosion were investigated. The feeding indices, such as the approximate digestibility (AD), the relative consumption rate (RCR), the relative growth rate (RGR), the efficiency of conversion of ingested food (ECI), and the efficiency of conversion of digested food (ECD) were determined at 72 h after treatment with different dosages of cyantraniliprole, and the contents of nutrients such as carbohydrates, proteins and lipids were also analyzed at 24, 48 and 72 h after cyantraniliprole treatment. 【Result】The result of bioassay showed that cyantraniliprole had high toxicity against 4th instar larvae of A. dissimilis, the LC₅₀ value was 0.66 µg·g^-1 artificial diet. The concentrations that caused 5% and 25% mortalities were 0.13 and 0.34 µg·g^-1 artificial diet, respectively. After being treated with cyantraniliprole, the durations of the 4th instar to 6th instar larvae stage were significantly prolonged 1.63, 1.75 and 5.48 days in the LC₅, LC₂₅ and LC₅₀ treatments, respectively. The period of pupae was prolonged while the period of adults was shortened, the pupation and eclosion rate were also declined. In addition, the pupal weight of female A. dissimilis in LC₅ (130.2 mg), LC₂₅ (127.8 mg) and LC₅₀ (127.5 mg) treatment groups was significantly reduced compared with the control group (146.7 mg). However, there was no significant difference in the pupal weight of male. The fecundity of female adults was also greatly decreased after treated with sublethal concentrations of cyantraniliprole, with 755.1, 558.8, 506.9 and 462.8 eggs/female, in the control, LC₅, LC₂₅, and LC₅₀ group, respectively. Meanwhile, the oviposition period was also significantly shortened, but cyantraniliprole did not have significant effect on the adult preoviposition period. compared with the control group, cyantraniliprole had markedly antifeedant effects, which significantly decreased the RGR, RCR, ECI and ECD of larvae. The amount of total carbohydrate in the 4th instar larvae of A. dissimilis in cyantraniliprole-treated groups decreased significantly compared with the control group in 24 h, similarly, from 48 h to 72 h. Meanwhile, the effects on the contents of proteins and lipids in the treatment groups were similar to carbohydrates. All these adversely affected the normal growth and development of A. dissimilis. 【Conclusion】Low-lethal dosages of cyantraniliprole can suppress the development and fecundity of A. dissimilis population, which is beneficial to the long-term control of A. dissimilis.