Cordyceps javanica (Frieder. & Bally) (Hypocreales: Cordycipitaceae) is an important entomopathogenic fungus that is used as a mycoinsecticide to control pests such as aphids and whiteflies. However, few studies have been done on the pathogenicity of C. javanica to aphids. Using a virulence assay, we studied the entomopathogenic fungus C. javanica IJ-tg19, which has high virulence to the aphid Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae). We compared conidial germination and activity of cuticle-degrading enzyme (subtilisin-like serine protease (Pr1) and chitinase) of C. javanica IJ-tg19 with the entomopathogenic strains Cordyceps fumosorosea (Wize) (Hypocreales: Cordycipitaceae) IF-1106 and Beauveria bassiana (Balsamo) (Hypocreales: Cordycipitaceae) BB-1339. The infection process of C. javanica IJ-tg19 strain to A. pisum was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that germination time of conidia of C. javanica IJ-tg19 and C. fumosorosea IF-1106 was shorter than that of B. bassiana BB-1339, and the germination rate was significantly higher than the BB-1339 strain. The germ tube of IJ-tg19 was accompanied by mucilage secretion during the body surface germination of A. pisum. The activity of total Pr1 and chitinase of IJ-tg19 reached their highest values at 48 h post-inoculation (PI), and the activities were significantly higher than those of IF-1106 and BB-1339. SEM and TEM observations showed that the infection peak was at 24 h PI, and mycelia had entered the hemocoel cavity of A. pisum at 48 h. These results indicate that C. javanica IJ-tg19 has several desirable attributes to act as an effective agent for the biological control of aphids.

爪哇冬虫夏草(Frieder. & Bally) (Hypocreales: Cordycipitaceae) 是一种重要的昆虫病原真菌，用作真菌杀虫剂以控制蚜虫和粉虱等害虫。然而，鲜有关于爪哇螟虫对蚜虫致病性的研究。使用毒力测定法，我们研究了昆虫病原真菌C. javanica IJ-tg19，它对蚜虫Acyrthosiphon pisum (Harris)（半翅目：蚜科）具有高毒力。我们比较了C. javanica IJ-tg19 与昆虫病原菌株Cordyceps fumosorosea的分生孢子萌发和角质层降解酶（枯草杆菌蛋白酶样丝氨酸蛋白酶（Pr1）和几丁质酶）的活性(Wize) (Hypocreales: Cordycipitaceae) IF-1106 和Beauveria bassiana (Balsamo) (Hypocreales: Cordycipitaceae) BB-1339。通过扫描电子显微镜（SEM）和透射电子显微镜（TEM）观察了C. javanica IJ-tg19菌株感染豌豆的过程。结果表明，C. javanica IJ-tg19和C. fumosorosea IF-1106的分生孢子发芽时间均短于B. bassiana BB-1339，发芽率明显高于BB-1339菌株。IJ-tg19的胚芽管在豌豆体表萌发过程中伴随着粘液分泌. IJ-tg19总Pr1和几丁质酶活性在接种后48 h达到最高值，明显高于IF-1106和BB-1339。SEM和TEM观察表明感染高峰出现在感染后24 h，菌丝体在48 h进入豌豆血腔。这些结果表明C. javanica IJ-tg19 具有几个理想的属性，可以作为蚜虫生物防治的有效药剂。