The effect of short-term high temperature stress on the biological characteristics of Neoseiulus barkeri (Hughes) carrying Beauveria bassiana (Vuillemin)
Author of the article:LIU Ming-Xiu, NIMA Yu-Zhen, FENG Xiao-Tian, LI Xuan-Liang, YANG Yang, ZHANG Kai-Jun, XIANG Dong, CHE
Author's Workplace：Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River, Chongqing 400715, China
Key Words：Beauveria bassiana; Neoseiulus barkeri; high temperature stress; function response; coordinated application
Abstract：
Abstract [Aim] To determine the effect of short-term high temperature stress on the biological characteristics of Neoseiulus barkeri (Hughes) carrying Beauveria bassiana (Vuillemin). The findings of this study will determine the feasibility of using N. barkeri carrying B. bassiana for the control of Eotetranychus kankitus (Ehara) in short-term high temperature environments. [Methods] The residual amount of B. bassiana conidia carried by N. barkeri was counted following exposure to high-temperature stress at 35 ℃ for 2, 4, and 6 hours. We evaluated the functional response of B. bassiana-carrying N. barkeri in controlling E. kankitus, and its effects on development and fecundity following exposure to high-temperature stress at 35 ℃ for 4 hours. [Results] After 2, 4, and 6 hours of short-term high temperature stress at 35 ℃, there was no significant difference in the number of conidia carried by female N. barkeri compared to 25 ℃ (c2 = 0.001, P = 0.978). The number of conidia carried gradually decreased over time. However, one female N. barkeri still carried 105 conidia after 6 hours. Additionally, after 4 hours of high-temperature stress at 35 ℃, there was no significant change in the predation rate of B. bassiana-carrying N. barkeri female on E. kankitus nymphs compared to the rate at 25 ℃ (P > 0.05), although the predation potential (a¢/Th) did increase slightly. However, when exposed to high-temperature stress at 35 ℃ for 4 hours per day, B. bassiana-carrying N. barkeri exhibited accelerated development, a prolonged pre-oviposition period, reduced fecundity, and a decreased lifespan. [Conclusion] Under short-term high temperature conditions, N. barkeri can carry a substantial amount of B. bassiana conidia. Furthermore, when N. barkeri carries B. bassiana, it is still able to effectively control E. kankitus. However, it is important to note that exposure to short-term high temperature stress negatively impacts the reproduction and lifespan of N. barkeri carrying B. bassiana. This study provides valuable insights for the development of sustainable and integrated strategies to control citrus pest mites by combining the use of fungi and predatory mites.