Stability of Spodoptera frugiperda multiple nucleopolyhedrovirus Hub1 and its field efficacy against S. frugiperda

Spodoptera frugiperda is a highly destructive pest that can damage crops and pose a serious threat to food security. The S. frugiperda multiple nucleopolyhedrovirus Hub1 (SpfrNPV Hub1) represents the pioneering virus specifically targeting S. frugiperda, thereby exhibiting promising prospects for practical applications. This paper aims to assess the impact of various temperature, pH value, and light conditions on the stability of SpfrNPV activity using the residual film method. The stability test results demonstrated that SpfrNPV Hub1 exhibited stability at pH 4 and pH 7, as well as at temperatures of 4 ℃ and 25 ℃. However, it displayed reduced stability at pH 9 and proved to be unstable under conditions of 54 ℃ and 4000 lx illumination. The results of field trials revealed that SpfrNPV Hub1 2 billion PIB(polyhedral inclusion body) /mL SC effectively controlled S. frugiperda. When applied at a dose of 1500-1875 mL/hm², the control efficiency remained consistently high, ranging from 81.18% to 82.57% at 7 days after application and from 81.23% to 83.06% at 14 days after application, indicating long-lasting effect. This study provides valuable insights into the impact of temperature variations, pH levels, and light conditions on the activity of SpfrNPV Hub1 while offering essential technical guidance for its application in controlling S. frugiperda.