effectonsoybeanandtheeffectsofitssymbiotic relationship with soybean on the feeding behavior of S exiguaby seed soaking，root irrigation and foliar spraying methods.The results showed that the cumulative corrected mortality ofthethird instarlarvaewas 56.92% after 14 days of Bb378 treatment，and the LC₅₀ was 3.7×10⁷ （24 CFU/mL.When the content of Bb378 spore suspension was 1×10⁸ CFU/mL，seed soaking and root irrigation

treatments hadobvious effectson plant height，leaf area and fresh weight of soybean，partof which were significant increased compared with the control. When the suspension contents of Bb378 were 1×10⁷ CFU/mL and 1×10⁶ CFU/mL ，respectively，foliarspraying hadthegreatest efectonleafarea（thetwenty-firstdayaftertheseedlingswerealigned）and fresh weight of soybean，respectively. In addition，when the contents of Bb378 were 1×10⁸ CFU/mL and 1×10⁷ CFU/mL， treatments of seed soaking，rotirrigationand foliar spraying had good repellent efect on the newly hatched larvae of S .exiguaontewhole，whiletreatmentsofseedsoakingandrootirigationhadsignificantrepellntefectonthethirdinstarlarvae of S exigua.The results showed that B .bassiana Bb378 could promote soybean growth after inoculation，and the B bassiana-soybeansymbiont hadarepelant efectonS.exigua，which provided technicalsupportforthe furtherapplication of B . bassiana insecticide in the field.

KeyWords：Beauveria bassiana；soybean；growth-promoting；repellant；Spodoptera exigu

球孢白僵菌（Beauveriabassiana）是最早被发现和认识的一类昆虫病原真菌，是昆虫种群的天然“杀手”，可感染700多种昆虫，兼有环境友好、易规模化生产等优点，已被开发并广泛使用[1-2]。但在球孢白僵菌的应用中仍存在杀虫速率缓慢、防效易受环境因素影响等限制，为了更好地发挥球孢白僵菌的生防潜力，研究人员开始尝试新的使用方法，以探究更高效地利用球孢白僵菌的技术。如以小麦、花生油和球孢白僵菌孢子粉按 35：1：9 （质量比）混合可显著提升对红火蚁的诱集效果[3]；球孢白僵菌-玉米共生体能够抑制亚洲玉米螟对玉米的取食和玉米螟生长，并通过调节玉米的保护酶和抗性基因的表达对昆虫产生生态调控作用4；球孢白僵菌以灌根或浸种处理方式成功定殖至玉米植株体内，可明显驱避和抑制亚洲玉米螟幼虫对玉米的取食[5]。刘晓丽等[6发现白僵菌种子包衣处理对大豆植株生长具有明显促生作用，且植株对八字地老虎幼虫具有杀虫活性。

甜菜夜蛾（Spodopteraexigua）是一类在全球范围内周期性暴发的杂食性害虫，可危害大豆、玉米等多种农作物，是重要的农业害虫[7]。长期以来化学杀虫剂作为控制大豆甜菜夜蛾危害的重要手段，取得了良好的效果，但随之也带来了抗药性难题[8-]。监测发现甜菜夜蛾已对大豆田常用药剂氯虫苯甲酰胺和甲维盐等产生了中水平到高水平的抗性[12]，导致防治效果不理想，因此，甜菜夜蛾的防治迫切需要寻找替代措施。球孢白僵菌等昆虫病原真菌作为重要的生防资源，具有控虫效果持续、不易产生抗性等优势，符合生态农业发展的需求，应用潜力巨大，利用球孢白僵菌与植物的共生作用，可能会带来新的植保效益。……