斜纹夜蛾雌蛾生殖系统发育的形态变化

为探讨能供预测应用的斜纹夜蛾[Spodoptera litura (Fabricius)]雌蛾生殖系统发育调查分级,研究了室内饲养的斜纹夜蛾雌蛾的生殖系统发育形态变化,着重对脂肪体、卵巢小管、交配囊和中输卵管进行了观察和拍照,同时对高空诱集的斜纹夜蛾雌蛾卵巢进行了研究.基于研究结果,建议把雌蛾的卵巢发育分为5个级别.     

小麦间作豌豆和挥发物释放结合不同器械施药对麦田害虫和天敌的影响

利用作物间作和挥发物释放的农田害虫生态调控“推-拉”技术,可以增加田间生物多样性,提高天敌的控害效果,减少农药使用。然而,为了实现害虫防控的农药减施增效目的,不同施药器械施药结合生态调控技术对害虫和天敌种群动态以及作物产量的影响研究较少。本研究采用新型自走式喷雾机和传统手动背负式喷雾器两种施药器械,分别对单作小麦、小麦豌豆间作、小麦豌豆间作＋蚜虫报警激素反式-β-法尼烯（EBF）,以及小麦豌豆间作＋水杨酸甲酯（MeSA）等处理下施用杀虫和杀螨剂,系统调查分析四种处理对小麦产量、小麦蚜虫、红蜘蛛,以及相关天敌发生量的影响。结果显示,自走式喷雾机的施药速度显著高于手动背负式喷雾机。不同施药器械防治小麦害虫可以显著影响小麦的穗粒数和产量。自走式喷雾机施药的间作＋MeSA处理的小麦千粒重和产量明显高于其他处理。在单作田中,两种施药器械对荻草谷网蚜和瓢虫平均发生量无显著影响,自走式喷雾机施药处理的禾谷缢管蚜、红蜘蛛和天敌僵蚜的发生量显著降低。自走式喷雾机施药的间作＋MeSA田的荻草谷网蚜、禾谷缢管蚜和红蜘蛛的发生量明显低于其他处理,而瓢虫的发生量显著高于其他处理。两种药械施药情况下,间作＋MeSA田小麦上僵蚜量均明显高于单作田。两种施药器械施药前,单作和间作＋MeSA田红蜘蛛发生量较低;施药后间作＋MeSA处理的小麦红蜘蛛密度一直维持比较低的水平;间作＋EBF和间作＋MeSA的两个处理在喷药后第二次调查才达到红蜘蛛数量低峰,而同期的单作处理红蜘蛛发生数量有明显回升。总之,小麦间作＋MeSA处理可以显著增加小麦产量,对于麦田小麦蚜虫和红蜘蛛的防控效果和对天敌的吸引保护效果最好。对麦田喷药效率、对害虫防控效果和增加小麦产量综合评价,自走式喷雾机具有明显优势。然而,需要注意的是对比传统手动喷雾器喷药可能对天敌寄生蜂有更强的非靶标作用。     

中国转基因抗虫玉米的商业化策略

玉米是全球播种面积最大的粮食作物,事关世界粮食安全。鳞翅目和鞘翅目害虫是影响玉米产量和品质的重要因素,长期以来多数国家采取以喷施化学农药为主的防控策略,但存在较高的使用成本和环境风险等问题。作为新一代的害虫防控技术,转基因抗虫玉米于1996年开始在美国商业化种植,并迅速推广到巴西等主要玉米生产国家,成为防控草地贪夜蛾Spodoptera frugiperda和欧洲玉米螟Ostrinia nubilalis等重大害虫的核心技术。该文综述了全球转基因抗虫玉米商业化的历史和防控害虫的作用,分析了美国对欧洲玉米螟和草地贪夜蛾等靶标害虫抗性治理的成功经验以及巴西等南美国家草地贪夜蛾对多种转基因抗虫玉米产生抗性的成因与教训。基于中国转基因抗虫玉米转化事件的研发现状、玉米生产模式、玉米害虫的区域发生特点和迁飞生物学等特性,提出在南方和西南山地丘陵玉米区种植包含Vip3A的多基因叠加抗虫玉米从源头防控草地贪夜蛾,在黄淮海夏玉米区种植包含Cry2A的多基因叠加抗虫玉米从源头防控棉铃虫Helicoverpa armigera,在北方春玉米区种植包含Cry1A的多基因叠加抗虫玉米从源头防控亚洲玉米螟Ostr...     

A larval specific OBP able to bind the major female sex pheromone component in Spodoptera exigua(Hübner)

Odorant binding proteins(OBPs) in insects are postulated to solubilize and transport the hydrophobic odorants across the hydrophilic antennal lymph to the olfactory receptors(ORs) located on the dendrite membrane of the sensory neurons. OBPs in adult insects have been intensively reported, but those in larvae are rarely addressed. In our study, a full-length OBP c DNA, namely Sexi OBP13, was cloned by RT-PCR and RACE strategy from the heads of Spodoptera exigua larvae. The quantitative real-time PCR(q PCR) measurement indicated that Sexi OBP13 was highly expressed in larval head, but very low in other parts of larva and was not detected in any tissues of adult. The binding affinities of Sexi OBP13 to plant volatiles and female sex pheromone components were measured by competitive binding assays. Interestingly, Sexi OBP13 displayed a high binding affinity(Ki=3.82 μmol L–1) to Z9,E12–14:Ac, the major sex pheromone component of S. exigua, while low affinities to the tested host plant volatiles(Ki27 μmol L–1). The behavioral tests further confirmed that Z9,E12–14:Ac was indeed active to elicit the behavioral activity of the third instar larvae of S. exigua. Taken together, our results suggest that Sexi OBP13 may play a role in reception of female sex pheromone in S. exigua larvae. The ecological significance of the larvae preference to the adult female sex pheromone was discussed.