川硬皮肿腿蜂携带松墨天牛致病菌的研究

The potential for using Scleroderma sichuanensis as a vector for fungal pathogens of Monochamus alternatus

【目的】以生物导弹为理念,应用寄生性昆虫携带病原物双重防治松墨天牛Monochamus alternatus是目前研究的新领域,更是松材线虫病Bursaphelenchus xylophilus防治的新途径。【方法】本文以川硬皮肿腿蜂Scleroderma sichuanensis为载体,通过测定4株松墨天牛致病菌的孢子粉和孢子悬浮剂对其毒力大小和川硬皮肿腿蜂对4株菌的2种剂型的初始携带量及存留量,分析不同菌种与不同剂型对川硬皮肿腿蜂的影响和川硬皮肿腿蜂体表孢子脱落趋势。【结果】川硬皮肿腿蜂雌成蜂携带粉剂孢子的死亡率高于携带悬浮剂的,但川硬皮肿腿蜂对粉剂孢子的携带量却远远高于悬浮剂孢子的携带量。当喷施孢子悬浮剂时,川硬皮肿腿蜂的累计死亡率随浓度增加而增加,同样携带量也随浓度增加而增加;白僵菌对川硬皮肿腿蜂的毒力较绿僵菌高,致死速率也较绿僵菌大,但川硬皮肿腿蜂对白僵菌的携带效果却比绿僵菌的效果好。并且不论剂型和菌种,川硬皮肿腿蜂体表的孢子在第1d后都脱落最为明显,而后均保持较缓慢脱落。【结论】本研究证明川硬皮肿腿蜂携带松墨天牛致病菌的方法是可行的,其中白僵菌孢子粉更适合携带。

[Objectives] Based on the biological missile concept, the use of pathogen-carrying parasitic insects is potentially a new way of preventing and controlling both Monochamus alternatus and pine wilt disease. [Methods] We measured the virulence of conidial powder and spore suspensions of four pathogenic fungal strains carried by Scleroderma sichuanensis, and the initial and residual pathogen load of each strain. We then analyzed the effects of each pathogenic strain and pathogen load on S. sichuanensis, and the shedding of pathogen spores on the body surface this species. [Results] The mortality rate of females carrying conidial powder was higher than that of those infected with spore suspension, but the pathogen load of conidial powder was much higher than that of spore suspension. For suspensions, both the cumulative mortality and pathogen load of S. sichuanensis increased with increasing concentration. The virulence and the mortality rate induced by Beauveria bassiana was higher than that of Metarhizium anisopliae, but the pathogen load of B. bassiana was higher than that of M. anisopliae. Irrespective of dosage or strain, most spores on the body surface of S. sichuanensis fell off after the first day after which the rate of spore loss continued more slowly. [Conclusion] S. sichuanensis is an effective vector of fungal pathogens of M. alternatus, particularly B. bassiana.