Stability of Spodoptera frugiperda multiple nucleopolyhedrovirus Hub1 and its field efficacy against Spodoptera 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 (SpfrMNPV 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, and light conditions on the stability of SpfrMNPV activity using the residual film method. The stability test results demonstrate that SpfrMNPV 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 SpfrMNPV Hub1 2 billion PIB/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 treatment and from 81.23% to 83.06% and 14 days after treatment, indicating long-lasting effect. This study provides valuable insights into the impact of temperature variations, pH levels, and light conditions on the activity of SpfrMNPV Hub1 while offering essential technical guidance for its application in controlling S. frugiperda.