金龟子绿僵菌在松墨天牛成虫僵虫体上的宿存动态

Survival Dynamics of Metarhizium anisopliae on Cadaver of Monochamus alternatus Adults

将被金龟子绿僵菌MaYTTR-04菌株感染后的松墨天牛成虫僵虫放置于林地中,研究在林间自然条件下僵成虫体上绿僵菌孢子的宿存动态。通过2年试验发现:林间松墨天牛僵成虫体上孢子数量在试验初期(42天内)显著下降,以后下降趋势趋缓,84天后至僵虫完全腐烂基本稳定在每成虫105个孢子数量级;林地僵虫体上的孢子在126天内萌发率均保持在90%以上的较高水平。通过对不同时间僵虫体上绿僵菌对松墨天牛成虫的致病力研究发现,在107,106孢子.mL-1数量级的接种量下,僵成虫体上的孢子致病力与对照差异不显著,说明僵虫体上的孢子在野外宿存的过程中可以较好地保持其致病力。

Monochamus alternatus is a major insect vector transmitting pinewood nematode disease,an important quarantine disease of pine forests.In this paper,the muscardine cadavers of M.alternatus adults died by Metarhizium anisopliae were put in the forest floor,and the dynamics of spores on the cadaver in natural status was studied.The knowledge would provide a theoretic basis for M.alternatus＇s biocontrolling using M.anisopliae as an agent.In the two-years experiment,the amount of spores on the cadaver decreased significantly in the first 42 days,and then decreased slightly.The amount of spores on the cadaver was maintained at the level of 105 spores per adult from the 84th days to the end of the experiment.Spore germination rates were always above 90% within 126 days.Then the virulence of M.anisopliae to M.alternatus was tested in different time,and the difference of the virulence between the spores and the control was not significant when M.alternatus inoculated with 10 7 or 106 spores·mL^-1.The results showed that spores on the cadaver could keep high virulence to M.alternatus for a long time in field.