绿僵菌对茄二十八星瓢虫的毒力测定

Toxicity Determination of Henosepilachna sparsa orientalis Diek by Metarhizium anisopliae

用培养的金龟子绿僵菌对二十八星瓢虫幼虫进行毒力试验,并对死亡的成虫取样、制片、观察,结果是孢子浓度为1×108孢子/ml时,绿僵菌对不同龄期幼虫的毒杀作用明显,而成虫对高浓度绿僵菌更敏感。组织切片观察表明,绿僵菌主要通过孢子接触寄主表皮来感染成虫,感染后的虫体出现一系列组织病理变化,菌丝侵染各种组织器官,肌肉组织、中肠、马氏管、消化道等遭到破坏,脂肪组织崩解,虫体内有大量菌丝和孢子。

The toxicity experiment on the larva of Henosepilachna sparsa oricntalis Dieke was conducted by cultured Metarhizium anisopliae and the death adults were sampled and observed. It was found that Metarchizium anisoplias had a perfect toxic effect against the larva of Henosepilachna sparsa orientalis and it also had an obviously effect against the adults. The observation with the paraffin sections proved that the Metarchizium anisoplias infected the adults mainly by attaching its spores to the epidermis of the insect. And there would be a series of histopathological changes in the insect tissues after being infected. The mycelium would infect many kinds of tissues and organs. The muscle tissues, the mid gut, the malpighian tube and the digest tube were damaged and the fat tissues were destroyed. And a lot of fungi spores were produced in the insects.