利用胡瓜新小绥螨携带玫烟色拟青霉菌兼防茄子蚜虫和叶螨

摘要

利用胡瓜新小绥螨携带玫烟色拟青霉菌兼防蚜虫和叶螨是一种新的生物防治思路，为了证实其可行性，笔者对所得玫烟色拟青霉菌的孢子萌发条件及毒性等进行研究。通过小容器空气湿度调节法测定分生孢子最适萌发温、湿度；并在适宜条件下，测定1×104~1×108孢子/ml浓度的分生孢子悬浮液对蚜虫和胡瓜新小绥螨的毒力；设置1.空白对照；2.释放50头胡瓜新小绥螨；3.喷洒20 ml 107孢子/ml孢子悬浮液；4.喷洒20 ml 107孢子/ml孢子悬浮液后释放50头胡瓜新小绥螨；5.释放20头沾满分生孢子粉的胡瓜新小绥螨；6.释放50头沾满分生孢子粉的胡瓜新小绥螨的6种处理，进行盆栽试验。结果表明玫烟色拟青霉菌该菌株分生孢子最适萌发温、湿度为25~30℃、95%~100% RH，在此条件下，第10天时，1×108孢子/ml浓度下，蚜虫和胡瓜新小绥螨的累积校正死亡率分别为86.52%、41.78%，该菌株相同浓度的孢子悬浮液对蚜虫的毒力远大于对胡瓜新小绥螨的毒力，符合作为利用胡瓜新小绥螨携带，用以防治蚜虫的虫生菌的条件。通过盆栽试验，3、4、6处理的效果最好，第8天时蚜虫数量几乎降为0，而且相较而言，捕食螨带菌体最省工、省料，还可以兼防叶螨。所以，适宜温、湿度条件下，利用捕食螨带菌体同时防治蚜虫和红蜘蛛是最好的方法。%Using predatory mites Neoseiulus cucumeris Oudermans dusted with en-tomopathgen Paecilomyces fumosoroseus (Wize) Brown & Smith to control aphids and spider mites is a new idea of biological control. Some studies were conducted to confirm the feasibility of this idea. The germination condition of P. fumosoroseus conidia was determined by the method of different saturated salt solutions applying different humidity in smal containers, and the pathogenicity test and the pot experi-ment were also conducted, under a suitable condition. There were 6 treatments for pot experiment as fol owing: (1) CK; (2) releasing 50 N. cucumeris; (3) spraying 20 ml of 107 spores/ml conidial suspension; (4) releasing 50 N. cucumeris after spraying 20 ml of 107 spores/ml conidial suspension; (5) releasing 20 N. cucumeris dusted conidia of P. fumosoroseus; and (6) releasing 50 N. cucumeris dusted with conidia of P. fumosoroseus. The result showed that the germination condition of P. fu-mosoroseus conidia was 25-30 ℃ and 95%-100% RH, and under this condition, the 108 spores/ml conidia suspension caused a mortality of 86.52% in aphids and 41.78% in predatory mites after ten days. From the pot experiment, the numbers of aphids of treatment (3), (4), (6) were close to 0 at the 8th day. This study proved that the predatory mites N. cucumeris dusted with the entomogenous P. fu-mosoroseus could provide satisfactory control on both aphids and spider mites in potted eggplants under suitable temperature and humidity. The predatory mite vec-toring entomopathogen system could provide an economic and labor saving way for aphid control.