Abstract This study describes the biological activity of two Spodoptera frugiperda multiple nucleocapsid nucleopolyhedrovirus (SfMNPV) isolates recovered from the soil of maize crops in the states of Yucatan and Chiapas, Mexico (Sf-YUC and Sf-CHI). The biological activity was determined for four Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) field populations: Sf-Motozintla, Sf-Erongaricuaro, Sf-Abasolo, and Sf-Culiacancito. As a reference, a laboratory colony (Sf-Lab) was used. Biological characterization was compared with that for a characterized SfMNPV isolate from Nicaragua (Sf-NIC). The LC50 values for both the Sf-NIC and Sf-CHI isolates did not differ in any of the insect populations tested. In contrast, the Sf-YUC isolate was less active than the Sf-NIC isolate in the Sf-Motozintla population, but this isolate was more active in the Sf-Erongaricuaro and Sf-Abasolo populations. The killing speed and OB productivity were variable among isolates in each insect population. A small-scale field trial was performed to evaluate the degree of pest control achieved by the Sf-YUC isolate, applied at a rate of 3 × 1012 OBs/ha, in maize grown in central Mexico. The larval mortality caused by the virus was 58%, 78%, and 84% at 2, 5, and 7 d post application, respectively. At 7 d post application, the incidence of insect parasitoids in the virus treatment was significantly lower than in the control. In conclusion, the insecticidal characteristics of both Mexican isolates (Sf-CHI and Sf-YUC) varied according to their insect population. In addition, the Sf-YUC isolate may be suitable as the basis for a biopesticide for the control of S. frugiperda in Mexico.

中文翻译：

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来自墨西哥的两种草地贪夜蛾核多角体病毒分离株的生物学特征以及在小规模田间试验中对一种分离株的评价

摘要 本研究描述了从墨西哥尤卡坦州和恰帕斯州的玉米作物土壤中回收的两种草地夜蛾多核衣壳核多角体病毒 (SfMNPV) 分离株 (Sf-YUC 和 Sf-CHI) 的生物学活性。测定了四种草地夜蛾（JE Smith）（鳞翅目：夜蛾科）野外种群的生物活性：Sf-Motozintla、Sf-Erongaricuaro、Sf-Abasolo 和 Sf-Culiacancito。作为参考，使用了实验室菌落（Sf-Lab）。生物学特征与来自尼加拉瓜的特征性 SfMNPV 分离物 (Sf-NIC) 进行了比较。Sf-NIC 和 Sf-CHI 分离株的 LC50 值在任何测试的昆虫种群中都没有差异。相比之下，Sf-YUC 分离株在 Sf-Motozintla 种群中的活性低于 Sf-NIC 分离株，但这种分离株在 Sf-Erongaricuaro 和 Sf-Abasolo 种群中更为活跃。杀灭速度和 OB 生产力在每个昆虫种群中的分离株之间是可变的。进行了一项小规模田间试验，以评估 Sf-YUC 分离株在墨西哥中部种植的玉米中以 3 × 1012 OBs/ha 的比例施用的害虫控制程度。由病毒引起的幼虫在应用后第 2、5 和 7 天的死亡率分别为 58%、78% 和 84%。施用后7 d，病毒处理中的寄生蜂发生率显着低于对照。总之，墨西哥分离株（Sf-CHI 和 Sf-YUC）的杀虫特性因昆虫种群而异。此外，Sf-YUC 分离株可能适合作为控制金黄色葡萄球菌的生物农药的基础。