蝗虫微孢子虫Nosema locustae对红胫戟纹蝗Dociostaurus kraussi kraussi致病性及呼吸代谢的影响

【目的】研究蝗虫微孢子虫Nosema locustae对红胫戟纹蝗Dociostaurus kraussi kraussi致病性及呼吸代谢的影响,为筛选蝗虫微孢子虫适宜的新疆本地的活体增殖寄主提供实验依据。【方法】采用逐头口服法感染红胫戟纹蝗,以镜检法检测蝗虫感染情况,并用呼吸仪测量试虫的呼吸代谢。【结果】在6.5×105个孢子/头的感染剂量下,红胫戟纹蝗的感染率和死亡率分别为41.70%和72.22%。蝗虫微孢子虫的感染剂量与其毒力高度相关(r2=0.961),LD50为1.7088×104个孢子/头;随孢子浓度增加和感染时间延长,试虫的CO2释放率显著降低(P<0.05),但耗氧率没有显著变化。【结论】红胫戟纹蝗被微孢子虫感染后表现出典型症状,高剂量组感染下死亡率达到70%以上,由此推断红胫戟纹蝗可作为微孢子虫在新疆本地的潜在增殖寄主。

Pathogenicity of Nosema locustae to Dociostaurus kraussi kraussi

Objectives] To study the pathogenicity ofNosema locustae to Dociostaurus kraussi kraussi, and to provide an experimental basis for screening living hosts of N. locustae in Xinjiang. Methods] D. kraussi kraussi were orally infected with Nosema locustae and the virulence and effects of fungal infection on the host respiratory metabolism were determined. Results] The results show that, at a dose of 6.5×10^5 spores, the infection and mortality ofD. kraussi kraussi were 41.7% and 72.22%, respectively. There was good correlation between infective dose and virulence ofN. Iocustae （r2=0.961）, the LD50 was 1.7088× 1^04 spores. Compared to the control, increasing spore concentration and infection time significantly decreased CO2 emissions （P〈0.05）. Conclusion] N. locustae can infect D. kraussi kraussi with high lethality and has significant effects on the hosts＇ respiratory metabolism.