异色瓢虫对菜缢管蚜、禾谷缢管蚜和白杨毛蚜的捕食作用

异色瓢虫是一种重要的捕食性天敌,可捕食多种蚜虫,在生物防治中具有很大应用前景。研究了异色瓢虫对3种蚜虫(即菜缢管蚜、禾谷缢管蚜和白杨毛蚜)的捕食功能反应。结果表明:异色瓢虫对3种蚜虫的日捕食量中,其中四龄幼虫最大,成虫和三龄幼虫次之,1、2龄幼虫最小。捕食者对猎物的功能反应均属于Holling-Ⅱ型方程。     

Rapid phenotypic assessment of bird cherry-oat aphid resistance in winter wheat

Rhopalosiphum padi L. causes significant damage to winter wheat ( Triticum aestivum L.), even without obvious aboveground symptoms of injury. Our objectives were to develop a juvenile-plant bioassay for bird cherry-oat aphid (BCOA) resistance that allows rapid phenotypic differentiation. Central features of the bioassay include root and shoot weight measurements of 3-week-old seedlings produced in seed germination pouches, a 14-day aphid exposure period, and a non-infested control treatment to establish a baseline for expected biomass per genotype. Cultivars used in bioassay development were 'Illinois Rustproof' and 'Skala', which showed smaller BCOA-induced reductions in biomass than the more susceptible genotypes, 'Patrick' and 'Scout 66'. Mean reductions in root biomass were 48% for 'Patrick' and 'Scout 66', compared with 29% for 'Illinois Rustproof' and 'Skala'. This rapid and repeatable bioassay is extendable to large wheat collections and inbred line populations.     

七星瓢虫幼虫对两种麦蚜捕食作用的研究

在实验室恒温条件下,研究了不同龄期的七星瓢虫幼虫对麦长管蚜和禾谷缢管蚜的功能反应及数值反应,结果表明:(1)七星瓢虫各龄幼虫对两种麦蚜的功能反应均属Holling-Ⅱ型曲线,各龄日最大捕食量分别为3.4头,2.5头;16.6头,10.6头;36.1头,25.3头;89.9头,82.8头;(2)七星瓢虫幼虫对两种麦蚜的喜食性、增长率和发育速率均无显著差异;(3)七星瓢虫幼虫对两种麦蚜的取食在一阈值之下时,虫体不能完成发育,在阈值点或阈值之上时,取食量与发育速率及增长率皆呈线性关系,符合Beddington模型。     

禾谷缢管蚜的种群动态

以时空综合观分析了禾谷缢管蚜的种群动态,用模糊聚类分析方法将禾谷缢管蚜的数量发生动态分为 4 个状态,即凋落状态、初盛状态、盛发状态和衰减状态,认为应在初盛期进行化学防治。空间分布格局分析表明种群具有周期性聚集和扩散的规律。     

兰花叶枯病的病原鉴定

１９９４年，在深圳发现兰花叶枯病，该病害对兰花的危害极大，通过对兰叶病组织的分离、培养、纯化、接种及交互感染试验，根据病原菌的形态特征和致病性测定结果，鉴定其病原为李属柱孢霉。     

Relationship Between Several Biochemical Indexes and Resistance of Aegilops Species to Oat-Bird Cherry Aphids(Homoptera:Aphididae)

The biochemical mechanism of resistance of 9 Aegilops species including A.biuncialis,A.juvenalis, A.ovata, A.kotschyi var. varianilis, A.triaristata, A.tauschii, A.vavilovii, A.crassa and A.ventricosa in Triticeae to oat-bird cherry aphid (Rhopalosiphum padi) were reported for the first time. The results showed that the content of total phenols in seedling was not associated with resistance to this aphid. The level of DIMBOA was negatively related to intrinsic innate rate of increase (rm) of R. padi. Neither of soluable sugar nor total phenols in adult stage was associated with resistance level. However, concentrations of free proline and serine in leaf were positively related to rm of R. padi (rm =-0.0636+0.23xpro** ＋1.982xser*). The content of DIMBOA was high-negatively related to rm of R. padi (r=-0.819**). The low level of free proline and serine and high concentration of DIMBOA could be regarded as important elements for resistance of Aegilops species to R. padi.     

禾谷缢管蚜对温度梯度的行为反应

利用自制的温度梯度产生装置,研究了禾谷缢管蚜Rhopalosiphum padi的避热行为及其栖息分布与温度梯度之间的关系。其避热率随温度梯度场温差的增大而显著增加,温度梯度为27.0~22.7、32.0~23.8、37.0~25.3和42.0~27.7℃时,其避热率分别为52.5%、72.5%、92.1%和100%。高温适应性锻炼可显著提高其对高温的适应能力,分别经15和35℃预适应温度训练1.5h后的成蚜,避热率分别为77.5%和64.2%。不同发育阶段的蚜虫在温度梯度场内的避热率无显著差异。总体上看,在26~43℃的叶片温度梯度内,50%的禾谷缢管蚜分布在27.7℃以下的区域内,99%的蚜虫分布在32.0℃以下的区域内。不同发育阶段的蚜虫在温度梯度内的分布有一定差异,99%的1龄若蚜分布在32.7℃以下的温度区域内,而99%的3龄若蚜分布区域为30.0℃以下。     

中华通草蛉幼虫对麦蚜捕食作用的初步研究

室内试验研究了中华通草蛉Chrysoperla sinica（Tjeder） （Neuroptera：Chrysopidae）1～3三龄幼虫对麦蚜Phopalosiphum padi（Linnaeus）的功能反应、二龄幼虫自身密度干扰作用和种内干扰效应。研究结果表明，幼虫的功能反应均属HollingⅡ型，日最大捕食蚜虫量1～3龄分别为331头、470头和767头，功能反应的参数表明中华通草蛉幼虫对麦蚜具有很大的捕食潜能。二龄幼虫自身密度干扰作用分别用Hassel ＆ Varley的模型E=QP-m和Beddington的模型E=at／（1＋btw（P-1））进行模拟，模拟模型分别为E=0．555P-0．765和E=0．515／（1＋0．551（P-1）），结果表明：随着二龄幼虫密度的增大，其捕食作用率随之减少。二龄幼虫的种内干扰效应试验表明，在捕食过程中捕食者密度的增大和蚜虫数成倍增加的时候，其捕食作用率仍然显著下降。