关键词: 金龟子绿僵菌, 生物学特性, 柑橘粉蚧, 时间-剂量-死亡率模型

Abstract: To definite the biological characteristics of Metarhizium anisopliae strain FM-03, the effects of temperature, pH, photoperiod, carbon source and nitrogen source on the mycelia growth and sporulation of FM-03 strain were tested. Then the mortality of FM-03-infected Planococcus citri was observed, and the time-dose-mortality model was constructed. Results showed that the optimal culture conditions for FM-03 growth and sporulation were 25℃, pH 7, 12L:12D, with lactose as carbon source and yeast extract as nitrogen source. With these conditions, the colony diameter and sporulation quantity of FM-03 were 6.17 cm and 3.70×10⁹ conidia/dish, respectively. The mortality of FM-03-infected P. citri increased with the increase in conidial concentration and the time of infection. The mortality increased more at 1×10⁸, 1×10⁷ and 1×10⁶ conidia/mL than at 1×10⁵ and 1×10⁴ conidia/mL. The highest corrected accumulative mortality of P. citri reached 82.02% at 1×10⁸ conidia/mL. Through Pearson's chi-squared test and Hosmer-Lemeshow test, the TDM model of FM-03 against P. citri showed an enhanced dose effect of FM-03 against P. citri with the prolong of infection time, and an improved time effect with the increase in conidial concentration. The LC₅₀ of FM-03 reached 6.03×10⁵ conidia/mL after an eight-day infection. The LT₅₀ of 1.00×10⁸ conidia/mL reached 4.53 d. In conclusion, with fast growth, high sporulation quantity, and strong pathogenicity against P. citri, M. anisopliae FM-03 shows an excellent potential in biological control of the pest.

Key words: Metarhizium anisopliae, biological characteristics, Planococcus citri, time-dose-mortality model