蜡蚧轮枝菌侵染黑刺粉虱体表过程的显微观察

采用扫描电镜研究了蜡蚧轮枝菌侵染黑刺粉虱成虫的过程。结果表明：接种蜡蚧轮枝菌孢子12h后，附着在虫体上的分生孢子萌发形成芽管，24h后，在复眼、腹部气孔、足的基节和翅的基部等部位菌丝侵入黑刺粉虱体内，接种72h后虫体被厚厚的菌丝层覆盖。分生孢子可以直接以芽管侵入表皮，也可以产生附着胞再侵入。分生孢子在黑刺粉虱体表萌发形成芽管，芽管顶端可形成附着胞，附着胞再形成侵入钉穿透寄主体壁。寄主体表结构影响形成附着胞的形状及穿透体壁时芽管长度。穿刺点处的小孔及附着胞周围发现粘状分泌物，为蜡蚧轮枝菌在入侵黑刺粉虱过程中穿透体壁时对寄主表皮产生降解作用的酶。

Microscopic observations of infection process of LecaniciUium lecanii on the cuticle of Aleurocanthus spiniferus

The infection process of the Aleurocanthus spiniferus （Quaintanca）by one isolates of the entomopathogenic fungus Lecanicillium lecanii（Zimmermann） Gams ＆ Zare was studied using scanning electron microscopy. The results indicated that eonidia germinated into germ tube within 12 h post inoculation for the isolates V3450, penetrated into the compound eyes, abdominal stoma, coxae of legs and basal parts of the wings of the host within 24h, and the host cadavers were covered with thick hyphae after 72 h of inoculation. The germinated conidia of the isolate either invaded the cuticle directly by germ tube or by producing appressorium during the course of infection. In host surface, the germ tube grew into hyphe and specialized appressorium were formed at hyphe tips. Appressofium formed penetration pegs. Hyphe penetrated the integument by means of their penetration pegs. The host cuticle structure affected appres- sorium formation shape and the length of germ tubes. Mucilaginous secretions were found around the small puncture point and appressorium, showing the production of the cuticle - degrading enzyme during the penetration of the cuti- cles of the host in the invasion process by the fungus I_. lecanii.