温度对花绒寄甲发育和生殖的影响

花绒寄甲Dastarcus helophoroides（Fairmaire）是寄生栗山天牛Massicus raddei（Blessig）、云斑天牛Batocera lineolata Chevrolat、松褐天牛Monochamus alternatus Hope、光肩星天牛Anoplophora glabripennis（Motschulsky）、锈色粒肩天牛Apriona swainsoni（Hope）等多种我国重大蛀干害虫天牛的主要天敌。为大量繁殖花绒寄甲防治天牛,本研究测定了花绒寄甲发育和生殖与温度的关系,包括卵期、幼虫期和蛹期的发育起点温度和有效积温;并研究在营养欠缺条件下不同温度处理成虫死亡率达50%时的天数,以及饲料供给充足状态下成虫的产卵量。结果表明,花绒寄甲卵期发育与温度的关系符合幂指数模型,发育起点温度和有效积温分别为12.80℃和126.09日度;幼虫期和蛹期发育与温度的关系符合抛物线型,发育起点温度和有效积温分别为11.7℃、139.0日度和13.9℃、265.24日度。在16～19℃、营养缺乏条件下,成虫死亡率达50%的时间为62～63 d,表明该天敌具有较强的耐饥力。在22～25℃、食料供给充分条件下,成虫产卵量最大,人工大量繁殖和饲养花绒寄甲的最适温度为22℃。只要食料充分,花绒寄甲成虫在所有温度处理下的寿命均达4年以上。     

花绒寄甲成虫饲料、诱导木覆盖物及接种比例的优化

为使花绒寄甲尽早获得核桃林"环境气味",培育出适合防治核桃林天牛的花绒寄甲生物型,提高其成活率和产卵量,对花绒寄甲成虫饲料、诱导木覆盖物及接种比例进行了优化研究。结果表明,选用(麦麸∶发酵核桃叶粉=1∶1)混合饲料饲养获得的黄粉虫蛹喂饲花绒寄甲成虫,其成虫死亡率最低(0),产卵量最高(668.87粒)。以表面质地粗糙、吸水性和透气性强的滤纸作为产卵诱导木覆盖物时最有利于诱导花绒寄甲产卵。花绒寄甲幼虫对大麦虫蛹寄生的嗜好优于黄粉虫蛹,其中大麦虫蛹和黄粉虫蛹分别作为替代寄主时的最佳接种比例分别为4∶1和1∶1。     

大麦虫作为替代寄主和人工饲料繁育花绒寄甲对其繁殖生物学的影响

花绒寄甲Dastarcus helophoroides是防治多种蛀干害虫天牛的重要天敌,为了解决人工大量繁育花绒寄甲的技术问题,本文选用大麦虫Zophobas atratus蛹作为繁育花绒寄甲幼虫的替代寄主,利用配置的人工饲料饲喂成虫,在实验室中连续饲养4代花绒寄甲,统计分析所繁育出的每代花绒寄甲成虫的产卵量、产卵前期时长、雌雄性比、成虫体长和体宽、体质量、卵的孵化率以及其后代幼虫的寄生率等,分析人工饲料和替代寄主对室内连续多代繁育的花绒寄甲繁殖生物学的影响。结果表明：花绒寄甲成虫的体长、体宽、体质量随着室内饲养代数的增加而减小;花绒寄甲成虫的产卵前期随着饲养代数的增加而延长,但后一种情况通过在饲料中添加维生素可有效解决。随着室内饲养花绒寄甲代数的增加和人工繁育时间的延长,平均每头花绒寄甲雌虫的产卵量增加;使用替代寄主繁殖4代后出现成虫雌雄性比下降,不符合1：1的情况。室内饲养4代的花绒寄甲卵的孵化率和初孵幼虫的寄生率几乎没有影响。通过对各个繁殖生物学指标的比较发现,饲喂改良人工饲料的花绒寄甲成虫的产卵前期在饲养多代后能明显缩短;利用大麦虫蛹繁育出的花绒寄甲后代雄虫数量明显多于雌虫;相反,利用改良人工饲料与花绒寄甲原始寄主松褐天牛幼虫配合使用,繁育出的第2、3代雌虫数量明显多于雄虫,差异显著。综上所述,利用大麦虫作为替代寄主会导致花绒寄甲后代雌雄性比下降,但可以通过改进饲料配方和利用原寄主饲养,在室内饲养多代后对花绒寄甲繁殖生物学的各项指标影响不大。因此,利用大麦虫和人工饲料等饲养技术综合应用,能够在室内人工规模化繁育花绒寄甲。     

花斑花绒寄甲生活史与其栖息地纬度的关系

为探明花斑花绒寄甲生活史特征与其栖息地的关系,采集了不同栖息地花斑花绒寄甲在室内饲养,系统比较了来自江西赣南、赣中、赣北及广东南雄不同纬度花斑花绒寄甲的产卵前期、发育历期、产卵量、孵化率、结茧率、羽化率与其栖息地纬度的关系。结果表明,在25℃下,不同采集地的花斑花绒寄甲野外代产卵前期为24.38～28.20 d,产卵前期随栖息地纬度的升高而延长,与地理纬度存在明显的正相关关系;不同采集地的花斑花绒寄甲卵历期7.73～11.73 d,幼虫历期6.91～12.82 d,花绒寄甲卵、幼虫发育历期随着纬度的变化呈现一种渐变的趋势,与地理纬度存在明显的正相关关系;而茧蛹历期(21.18～26.45 d)则与地理纬度存在明显的负相关关系。不同采集地的花斑花绒寄甲产卵量(野外代38.55～42.67粒/雌、F1代57.69～62.34粒/雌)随栖息地纬度的升高而增加,呈现一种渐变的趋势,且室内饲养的F1代产卵量显著高于野外代。而不同采集地花斑花绒寄甲的结茧率、羽化率、成虫率等具有分别相似的结果,即不同采集地间无显著差异,说明其特性与其栖息地纬度高低无显著相关性。     

花绒寄甲人工繁育及应用研究

为解决花绒寄甲人工繁育技术的关键问题,进一步提高产量,开展了低温保存对花绒寄甲卵活力的影响、替代寄主选择、成虫人工饲料配方、室内生活史等研究,并在后期初步开展了花绒寄甲对桃红颈天牛的野外防效试验。结果表明,4℃条件下保存0～60 d对花绒寄甲卵孵化率的影响存在显著差异,不经低温处理的卵孵化率最高,可达70.87%,低温保存60 d后,孵化率降为65.81%;大麦虫可作为花绒寄甲幼虫的替代寄主,最佳接虫比为1:5,此时化蛹率达70.40%,羽化率达94.03%;黄粉虫蛹、大蜡螟幼虫无法繁育出花绒寄甲成虫;黄粉虫幼虫干粉、大麦虫幼虫干粉、无菌水、脯氨酸、羟氨酸、丝氨酸、胱氨酸、葡萄糖、亚油酸混合配制的饲料使花绒寄甲成虫存活率达96.70%,单雌产卵量达161.10粒,产卵期持续43 d,是成虫的最佳人工饲料;经室内繁育的花绒寄甲一年发生2代,成虫寿命2～3年,卵期平均8.64 d、幼虫期平均6.63 d、蛹期平均36.88 d。花绒寄甲可用于防治桃红颈天牛,野外最佳释放比为8:1～ 10:1（天敌:天牛）,虫口减退率达72.70%。     

花绒寄甲对高温胁迫的适应能力及生理响应

商品化天敌昆虫在我国不同区域释放可能受到极端温度的影响和制约。花绒寄甲Dastarcus helophoroides（Fairmaire）是松墨天牛Monochamus alternatus Hope等蛀干害虫的重要天敌之一,具有良好的应用前景,但其在我国南方应用时控害效果常不稳定。以商品化花绒寄甲成虫为研究对象,并以常温25℃为对照,研究不同高温胁迫条件（33℃、36℃、39℃、42℃和45℃）对成虫的寿命、生殖、体内营养物质及抗氧化物活性的影响,旨在综合评价花绒寄甲成虫对高温胁迫的适应能力,为探讨其在我国南方松林中最佳释放时机、控害效果评价以及种群稳定性等方面提供科学依据。试验结果表明：高温胁迫（33℃~45℃）对花绒寄甲的成虫寿命具有显著影响,且随温度升高而显著缩短,据此可将高温区划分为致死高温区（42℃~45℃）、亚致死高温区（39℃~42℃）和高适温区（33℃~39℃）,其中花绒寄甲成虫在致死高温区内无法产卵,且卵块不能孵化;表明高温胁迫诱导花绒寄甲成虫产生强烈的抗逆代谢,消耗了大量营养物质,显著改变花绒寄甲成虫体内总糖、海藻糖和甘油三酯的含量;与此同时诱导花绒寄甲SOD、CAT活性的显著升高,POD活性的显著降低,与清除自由基有关。花绒寄甲成虫商品化种群耐受高温胁迫能力较弱,建议其在选择林间释放时间时,规避高温的潜在影响。应采用高适温区（33℃~39℃）进行驯化,以增强其成虫的耐高温及控害能力。     

利用四季豆饲养盲蝽的方法

四季豆是多种盲蝽的寄主植物,该研究旨在发展一个利用四季豆豆荚规模化饲养多种盲蝽的技术.研究结果表明:绿盲蝽与中黑盲蝽的若虫最佳饲养密度约为100头/盒(2L),成虫为60～80头/盒.绿盲蝽成虫喜好在切头豆荚的两端伤口处产卵,而中黑盲蝽喜欢在完整豆荚的两端产卵.养虫盒内添加一些弯曲的纸条有助于提高若虫存活率和成虫产卵量.产卵后的豆荚需晾干后放置在25～28℃、相对湿度60%～70%、光照16:8(L:D)的环境下,以减少豆荚腐烂和提高卵的孵化率.利用这一方法饲养盲蝽的若虫存活率、成虫产卵量和卵孵化率分别达60%、40粒和80%.     

用松褐天牛幼虫繁殖花绒寄甲产出成虫的数量和质量

为了提高花绒寄甲Dastarcus helophoroides（Fairmaire）对松褐天牛Monochamus alternatus Hope的寄生率,我们用松褐天牛幼虫繁殖花绒寄甲,研究不同接虫量和不同接虫时间对产出花绒寄甲成虫的影响。结果表明：用4龄松褐天牛幼虫繁殖花绒寄甲最好,1头幼虫接4头初孵花绒寄甲幼虫的产出率最高,为77.7%;产出量最大,平均为3.11头,而且产出的花绒寄甲成虫体长最长,平均为8.02 mm,体宽也最宽,平均为3.09 mm。在花绒寄甲幼虫孵化当天即接种,产出的成虫体长最长,平均为8.01 mm,体宽最宽,平均为3.10 mm。因此,最佳接虫量为每头松褐天牛幼虫接4头花绒寄甲幼虫,最佳接虫时间是花绒寄甲幼虫从卵中孵化出的当天。单头天牛幼虫产出的花绒寄甲成虫的数量对其个体大小影响均不显著。     

球孢白僵菌对松墨天牛的致病力及其与花绒寄甲的相容性

为探明昆虫病原真菌球孢白僵菌Beauveria bassiana与天敌昆虫花绒寄甲Dastarcus helophoroides的相容性,观察4株球孢白僵菌菌株的生长性状、产孢量以及孢子萌发率,并选用Bb3275和Bb202菌株测定其对松墨天牛Monochamus alternatus的致病力以及对花绒寄甲的毒力;同时在模拟环境条件下,分别用Bb3275和Bb202菌株的孢子悬浮液先侵染松墨天牛幼虫,再按1∶1比例将花绒寄甲与受侵染的松墨天牛置于同一环境下饲养,观察花绒寄甲的死亡率。结果显示,孢子悬浮液浓度为1×10⁶孢子/mL至1×10⁸孢子/mL时,Bb3275菌株和Bb202菌株对松墨天牛幼虫和成虫的致病力与对照组相比均有显著差异;经4种浓度Bb3275和Bb202菌株侵染花绒寄甲幼虫和成虫15 d后,仅在高浓度1×10⁸孢子/mL时表现出轻微致死作用,但花绒寄甲的存活率均高于85.00%;模拟条件下,松墨天牛幼虫校正死亡率均在80.00%以上,而同环境下花绒寄甲幼虫和成虫均表现出良好的活力,且侵染率为0。表明球孢白僵菌和花绒寄甲之间具有很好的相容性,可以同时应用于松墨天牛的生物防治。     

花绒寄甲赣南种群发育起点温度与有效积温研究

研究花绒寄甲[Dastarcus helophoroides(Fairmaire)]的生长发育与温度的关系,可为人工批量繁育提供依据。利用光照培养箱,在17、20、23、26℃和29℃5个恒温条件下饲养花绒寄甲,对其各虫态的发育历期、发育起点温度和有效积温进行了研究。结果表明,温度对花绒寄甲各虫态的发育历期有显著影响。花绒寄甲卵、幼虫、茧蛹的发育速率均与温度呈显著的正相关关系,卵期、幼虫期、茧蛹期的发育起点温度分别为16.34、15.63℃和11.31℃,有效积温分别为75.19、69.44℃和312.50℃。     

Localization of metabolic sites of action of herbicides

Time- and concentration-course studies were conducted to determine the effect of thirteen herbicides on photosynthesis, respiration, RNA synthesis, protein synthesis, and lipid synthesis using isolated single leaf cells. Each herbicide was from a different chemical class. Appropriate ¹⁴C-substrates and product purification procedures were used for each process prior to liquid scintillation counting. The most sensitive metabolic site of inhibition was photosynthesis for atrazine, bromacil, dichlobenil, monuron, and paraquat; RNA synthesis for dalapon and dinoseb; protein synthesis for chlorpropham; and lipid synthesis for CDAA, chloramben, 2,4-D, EPTC, and trifluralin. However, with several herbicides, one or more process was almost as sensitive as the one mentioned above. All herbicides inhibited more than one process, and the most sensitive site of inhibition may not be the same process that was inhibited the greatest at the maximum concentration and maximum exposure time used. Therefore, a concept of metabolic sites of action, rather than a primary site of action, appears to be more meaningful for herbicides.     

福寿螺配偶个体大小选择性初步观察

通过野外观察与实验研究,掌握了福寿螺的婚配体制及其配偶选择性规律。福寿螺与多数低等动物一样,其婚配属于乱交制,无固定配偶;雌螺对与其交配的雄螺个体大小没有选择性,而雄螺对雌螺的个体大小有选择性,倾向于与较大个的雌螺交配。     

青稞种子带菌检测及杀菌剂消毒处理效果

为了研究青稞种子外部和内部携带真菌情况,比较不同杀菌剂对青稞种子的带菌消毒效果和对幼苗生长的影响,为青稞种子播前包衣处理和种传真菌病害防控提供依据,采用离体平皿法对云南迪庆‘云青1号’、‘云青2号’和‘短白青稞’3个主栽品种进行带菌检测,并对种子进行拌种或浸种处理测定6种杀菌剂对种子消毒效果,分析杀菌剂对种子发芽和幼苗生长的影响。结果表明:供试青稞种子表面携带的优势菌群为青霉(Penicilliumspp.)、镰刀菌(Fusariumspp.);种子内部寄藏的真菌主要为镰刀菌、核腔菌(Pyrenophoraspp.)、附球菌(Epicoccumspp.)、丝核菌(Rhizoctoniaspp.)、链格孢(Alternariaspp.)和木霉(Trichoderma spp.)。青稞不同品种的种子表面及内部携带的真菌种类差异较大。致病性测定表明,镰刀菌对种子萌发和幼苗生长影响最大,后期出现幼苗坏死现象。45%咪鲜胺EW、75%百菌清WP、50%福美双WP对青稞种子携带真菌均有显著抑制作用和消毒效果,50%福美双WP消毒效果最优,达100%;45%咪鲜胺EW、75%百菌清WP、50%福美双WP处理对青稞种子发芽和幼苗生长均无显著影响。     

厚朴病虫害种类的初步调查

采用标准地法和线路调查法,对湖北恩施市新塘乡双河厚朴基地的厚朴病虫害进行了系统调查,记录主要虫害13种,其中叶部害虫9种,枝干害虫2种,根部害虫2种。厚朴主要病害5种。藤壶蚧、厚朴枝角叶蜂和厚朴新丽斑蚜为湖北省首次报道,小绿叶蝉为厚朴新寄主记录种。同时记录了藤壶蚧的天敌6种,其中寄生小蜂2种,瓢虫4种;厚朴新丽斑蚜的天敌昆虫8种。对藤壶蚧、厚朴枝角叶蜂和厚朴苗木根腐病等重要病虫害的发生规律进行了初步调查,同时提出了防治建议。     

Effects of timing and method of application of Penicillium oxalicum on efficacy and duration of control of Fusarium wilt of tomato

The effects of timing and method of application of Penicillium oxalicum on the control of fusarium wilt of tomato were investigated. Application of P. oxalicum to tomato seedlings in seedbeds reduced disease caused by Fusarium oxysporum f.sp. lycopersici in a growth chamber by 45–49% and in glasshouse experiments by 22–69%. Disease suppression was maintained for 60–100 days after inoculation with the pathogen in the glasshouse. No disease reduction was observed in tomato plants where P. oxalicum was applied to seeds. Treatment with P. oxalicum did not affect the population of F. oxysporum f.sp. lycopersici in the rhizosphere.     

Systems of designation of pathotypes of plant pathogens12

A variety of systems of designation has evolved to name pathotypes of plant pathogens. The systems were evaluated to determine those best suited for particular purposes. Virulence and avirulence/virulence formulae of pathotypes have advantage over the use of consecutive numbers or letters given in chronological order of pathotype discovery. As soon as pathotype information exceeds a certain level of complexity, mathematical codes are most advantageous, in particular two codes, octal notation and coded triplets. A more universal adoption of the most appropriate codes is recommended to ease communication and comparisons of results.     

Mode of action of etoxazole

The mode of action of the 2,4-diphenyl-1,3-oxazoline acaricide/insecticide etoxazole has been argued to be moulting inhibition, but experimental results supporting this hypothesis are lacking. This study investigated the effect of etoxazole on chitin biosynthesis in the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae). Etoxazole induced moulting defects in fall armyworm larvae similar, if not identical, to those caused by benzoylphenylureas, a well-known class of insecticidal chitin biosynthesis inhibitors. Furthermore, in contrast to untreated larvae, the chitin content in the integuments of larvae several days after treatment did not differ from that in freshly ecdysed individuals, thus suggesting strong chitin biosynthesis inhibition in vivo. A more detailed investigation of the inhibitory potential by incubating cultured integument pieces from larvae of S. frugiperda with [14C]N-acetyl-D-glucosamine, a radiolabelled chitin precursor, revealed I50 values of 2.95 and 0.071 microM for etoxazole and triflumuron respectively. The incorporation of radiolabel into potassium hydroxide-resistant material was inhibited by etoxazole in a dose-dependent manner. Based on these results, it is concluded that the acaricidal and insecticidal mode of action of etoxazole is chitin biosynthesis inhibition.     

Mode of action of meturine

The effect of meturine on the light processes of photosynthesis was studied.Meturine is a herbicide for weed control in potato and cotton crops. It is a N-phenyl—N-hydroxy—N′-methylurea.The experiments were carried out on isolated pea and spinach chloroplasts.When examining photosystem I, reduced DPIP was used as an electron donor, whereas methyl-viologen served as an electron acceptor. When examining photosystem II, DPIP represented the electron acceptor.The obtained experimental results have pointed to the absence of the effect of meturine upon the photoreaction I.Unlike N-phenyl—N′, N′-dimethylureas (CMU, DCMU) meturine has been a very weak inhibitor of photoreaction II.The authors explain the photoreaction II inhibition of chloroplasts from plants treated with herbicidal doses of meturine by conversion of N-phenyl—N-hydroxy—N′-methylurea into Hill reaction inhibitor(s). N-Phenyl—N′-methylurea can be one of such meturine metabolites.Meturine herbicidal action is accounted for by meturine transformation into Hill reaction inhibitor(s) in the plant tissues.     

甲基硫菌灵标样的制备

本文介绍了用进口甲基硫菌灵样品，采用溶剂萃取，高速离心，重结晶，高效液相色谱，红外光谱等分析方法进行系统分离与鉴定，得到其标样的方法。