保幼激素类似物对斜纹夜蛾核多角体病毒增殖的影响

分别用5×10⁶，1×10⁷，5×10⁷，1×10⁸ PIBs/mL 4种浓度的斜纹夜蛾核多角体病毒(SpltNPV)感染斜纹夜蛾末龄幼虫（第6龄），并于同龄期以10μg/头的保幼激素类似物(JHA) methoprene分别对各感染组进行点滴处理，以研究JHA对SpltNPV增殖的影响。研究表明，与对照组相比各不同浓度处理组病毒总产量分别提高227.06%、128.71%、52.62%、33.15%，平均单头病毒含量分别提高49.15%、48.40%、36.40%和31.11%，病毒感染死亡率分别提高119.21%、52.72%、12.64%和1.12%。其中以1×10.7 PIBs/mL感染再经JHA处理的病毒总产量和平均单头病毒含量最高，分别为1 701.8×10⁸PIBs和60.1×10⁸ PIBs。各处理组的病毒总产量和平均单头病毒含量均显著高于其对照组。在此基础上，进一步研究了JHA对染毒与未染毒宿主消化生理的影响。结果表明，JHA处理不仅延长了6龄幼虫的寿命，增加了其取食量，而且还显著提高了幼虫的食物转化率和病毒产量。

Effect of juvenile hormone analogues on multiplication of Spodoptera litura nucleopolyhedrovirus

The influences of juvenile hormone analogues (JHA) on multiplication of Spodoptera litura nucleopolyhedrovirus were studied. The early 6th instar larvae of Spodoptera litura were infected with four concentrations of SpltNPV, 5×10⁶，1×10⁷，5×10⁷and 1×10⁸ PIBs/mL, respectively, and then treated with 10 μg methoprene (a JHA) per larva. The results indicated that the total virus yield of the four concentration treatments with virus and methoprene increased by 227.06%, 128.71%, 52.62% and 33.15% than that of the control with virus and acetone, the mean yield per larva increased by 49.15%, 48.40%, 36.40% and 31.11% and the mean mortality increased by 119.21%, 52.72%, 12.64% and 1.12%, respectively. The greatest virus yield was obtained when the larvae were infected by 1×10⁷ PIBs/mL and then treated with 10  μg methoprene per larva, and the total virus yield and the mean virus yield per larva were 1 701.8×10⁸ PIBs and 60.1×10⁸ PIBs respectively. The virus yield of every treated group was significantly greater than that of the control group. Furthermore, the effects of methoprene on digestive physiology of infected and non-infected host were also studied. The results showed that not only the life duration and food consumption of 6th instar larvae were increased, the food conversion efficiency and virus yield of the larvae treated with methoprene were also increased significantly.