亚洲玉米螟感染白僵菌后组织病理学研究

STUDY ON PATHOLOGY OF OSTRINLA FURNACALIS AFTER INFECTION WITH BEAUVERLA BASSLANA

本文报道不同虫龄的玉米螟幼虫感染白僵菌后的组织病理学过程。随着虫龄的增加，白僵菌侵入虫体及虫体组织病变解体的速度减慢。对１～２龄和３～４龄幼虫，白僵菌菌丝分别在２４小时和４８小时穿透体壁，并于４８小时和９６小时后虫体全部解体。而对老熟幼虫４８小时，菌丝刚能穿透体壁的表皮层，７２～９６小时染菌的组织仍保留其各自的轮廓没有解体。观察老熟幼虫可以发现：菌丝穿过体壁后，先在血淋巴中扩散，进入脂肪体并大量增殖，然后向结构较疏松的消化道、丝腺、马氏管、生殖腺侵入，使这些组织的边缘逐步变的不清，内部充满菌丝，以至细胞整体形状消失而解体；最后进入结构致密的肌肉、丝腺导管和神经组织，使这些组织的细胞边缘不清，出现间隙，整个组织空泡化。

he pathological processes in the bodies of Ostrinia furnacalis after infection withBeauveria bassians are reported in this paper.Along with the growing up of the larvaethe infecting speed of B.bassiana to the disintegrated speed of insecttissues are reduced.To 1-2 instar larvae the germ tubes or hyphae passing through thecutex,then entering the kemolymph and lipoid of host need 36 hrs.after inoculation.But,to 3-4 and last instar larvae,this process need another 10-15 hrs.more.As to the disintegration of insecttissues happening after inoculation,the 1-2 instar larvae need 42-48 hrs.,the 3-4 instarlarvae,72-96 hrs.,and the last instar larvae,120-144 hrs. or longe. The infectingsequences of hyphae stages:(a)cutex;(b) hemolymph, lipoid;(c)alimentary tract,malpighian tubule,silk gland and reproductive gland;(d)muscles,silk gland duct andnerve cord.The pathological changes of insect tissues can be briefly described asfollows:the appering of vague edges,crevices and empty circles around or amongtissues then the happening of damage and disintegration of them.