【目的】 明确美国白蛾核型多角体病毒（Hyphantria cunea nudeopolyhedroviurs，HcNPV）的最佳增殖方法和最适保存条件，为HcNPV标准化生产提供理论依据和技术支撑。【方法】 利用活体增殖法，探究不同饲毒虫龄-病毒浓度组合、持续饲毒时间、幼虫饲毒温度和密度对HcNPV增殖量的影响，筛选最佳的HcNPV活体增殖方法；并利用生物活性测定法，研究不同病毒保存处理方式、保存时间、保存温度和保存剂对HcNPV活性的影响，明确最佳的保存条件。采用喂食法处理美国白蛾幼虫，利用血球计数板统计HcNPV增殖数量，以半数致死时间（LT₅₀）为指标评价病毒的杀虫活性。【结果】 当饲毒浓度为1×10⁶ OB·mL^﹣1、虫龄为5龄时病毒的增殖量为1.16×10¹⁰ OB/头，显著高于其他供试浓度和龄期；以3龄幼虫作为供试虫龄，饲毒浓度为1×10⁶ OB·mL^﹣1时，研究发现最佳饲毒温度为20 ℃，病毒增殖量达5.06× 10⁹ OB/头；随着持续饲毒时间的延长，病毒增殖量显著降低，从3.42×10⁹ OB/头降低至0.97× 10⁹ OB/头；幼虫饲毒密度为100头/箱（0.05头/cm²）时，病毒增殖量显著高于200-500头/箱，增殖量为4.94× 10⁹ OB/头。不同保存方法对HcNPV杀虫活性具有不同程度的影响。以病毒虫浆法和虫尸干燥粉碎法保存的病毒感染美国白蛾3龄幼虫的LT₅₀显著低于病毒液法和病毒干粉法；当保存时间不超过12个月时，病毒杀虫活性无显著变化；保存温度范围为﹣20-25 ℃时，病毒的杀虫活性未出现显著变化；筛选出最佳的保存剂为蔗糖（50%）和氯化钠（5%），LT₅₀分别为4.94 d和4.97 d。【结论】 在幼虫密度为0.05头/cm²的养虫箱中，使用浓度为1 × 10⁶ OB·mL^﹣1的HcNPV饲喂美国白蛾5龄幼虫一次，20 ℃下可获得最高产量的病毒；感病幼虫虫尸研磨成匀浆，添加蔗糖（50%）或氯化钠（5%）作为辅助剂，置于﹣20 ℃的冰箱内保存，可在12个月内保证HcNPV的最佳活性。

[Objectives]  To determine the optimal reproduction and storage conditions for the Hyphantria cunea nudeopolyhedrovirus (HcNPV) in order to provide a theoretical basis and technological support for the commercial production of this virus. [Methods]  The effects of different larval instars, virus concentration, duration, temperature and population density, were analyzed to identify the optimal condition for HcNPV reproduction in vivo. Effects of different formulations, times, temperatures and adjuvants on the stability of HcNPV storage were also investigated to determine the optimal HcNPV bioactivity assay method. In feeding bioassays, the number of proliferating occlusion bodies (OB) were recorded with a hemocytometer, and the lethal time (LT₅₀) was calculated to quantify the insecticidal activity of HcNPV. Third instar larvae fed a diet with a HcNPV concentration of 1×10⁶ OB·mL^﹣1 were used for follow-up experiments. [Results]  OB proliferation in 5th instar larvae reared on an artificial diet containing HcNPV at a concentration of 1×10⁶ OB·mL^﹣1 was significantly higher (1.16×10¹⁰ OB per larva) than in other treatments. The optimal temperature for HcNPV reproduction was 20 ℃, which resulted in 5.06×10⁹ OB per larva. The abundance of HcNPV virions significantly decreased from 3.42×10⁹ OB per larva after feeding for 1 day to 0.97×10⁹ OB per larva after feeding for 5 days. Larvae kept at a density of 100 larvae/box (0.05 larvae/cm²) had 4.94×10⁹ OB per larva, which was significantly higher than that of those kept at densities of 200, 300, 400, 500 larvae/box. The LT₅₀ of 3rd instar larvae infected from insect pulp and freeze-dried insect pulp was significantly lower than that of those infected from virus suspension and freeze-dried virus suspension. There was no significant change in the insecticidal activity of HcNPV when stored for less than 12 months and insecticidal activity did not change significantly over a range of storage temperatures from ﹣20 to 25 ℃. The best preservatives were sucrose (50%) and sodium chloride (5%), which had in LT₅₀ values of 4.94 days and 4.97 days, respectively. [Conclusion]  The highest yield of HcNPV was achieved by giving 5th instar H. cunea larvae a single feed of an artificial diet containing HcNPV inoculum at a concentration of 1×10⁶ OB·mL^﹣1 and keeping larvae at a density of 0.05 larvae/cm² at a temperature of 20 ℃. Grinding the bodies of diseased larvae into a slurry, adding sucrose (50%) or sodium chloride (5%) as adjuvants, and storing the resultant homogenate in a refrigerator at ﹣20 ℃, allowed HcNPV to be stored for up to 12 months with no loss in insecticidal activity.