棉铃虫对不同种植方式玉米为害的试验

近几年,棉铃虫在武威市玉米田连年暴发成灾,年发生面积2.4万～3.1万hm2,占玉米种植面积的50%～70%。为摸清其发生规律,给防治提供依据,笔者于2002年进行了玉米不同种植方式对棉铃虫发生为害影响的试验。1材料和方法1.1供试材料玉米品种中单2号;小麦品种永良4号。1.2试验方法试验在凉州区和平镇进行,前茬为小麦带玉米田。试验设单种玉米和小麦带玉米2个种植方式处理,重复3次,6个小区,顺序排列,小区面积300m2。单种玉米田不覆膜,于4月7日点种;小麦带玉米田于3月12日先分带播种小麦,4月15日点种玉米。其他管理措施同大田。1.3调查方法于棉铃虫…     

典型光活化毒素α-三噻吩对棉铃虫和亚洲玉米螟Na~+-K~+-ATPase的抑制作用

以棉铃虫 H elicoverpa armigera和亚洲玉米螟 Ostrinia furnacalis为试虫 ,建立 Na+- K+-ATPase最佳反应系统 ,研究典型光活化毒素 α-三噻吩 (简称 α- T)对 Na+- K+- ATPase的影响。棉铃虫 Na+- K+- ATPase活力最佳测试条件为酶源蛋白浓度 6μg/ m L ,反应温度 35～ 4 0℃ ,反应时间6min;亚洲玉米螟则为酶源蛋白浓度 8μg/ m L,反应温度 35℃ ,反应时间 6min。近紫外光照 (30 0～4 0 0 nm )对棉铃虫和亚洲玉米螟离体 Na+- K+- ATPase活力基本没有影响 ,但对活体活力有很强的抑制作用。光照和无光照条件下 ,α- T对两种昆虫离体和活体 Na+- K+- ATPase活力均有不同程度的抑制作用。光照组 α- T对亚洲玉米螟 Na+- K+- ATPase的抑制率高于无光照组 ,且处理浓度或剂量越高 ,其抑制率越大 ;对棉铃虫 Na+- K+- ATPase抑制作用不显著     

寄主植物对棉铃虫酯酶同功酶的影响

本实验采用聚丙烯酰胺凝胶垂直板型电泳法,分析了取食5种不同寄生植物的棉铃虫酯酶同功酶的变化。结果表明:在酶谱上,取食不同植物的棉铃虫体内的酯酶同功酶差异显著,酶带数和酶活性强弱均有不同;羧酸酯酶带数和酶活性高于胆碱酯酶。试验结果还证实了寄主植物中存在某种(待测)物质,诱导棉铃虫体内代谢发生变化。羧酸酯酶是参与这一代谢变化的主要水解酶之一。     

甘蓝夜蛾血球细胞离体培养的初步研究

本文对甘蓝夜蛾血球细胞的离体培养,以及细胞系的形态特征和生长特性进行了初步研究。利用M—M培养液,辅之以0.02％TC-199、0.06％胰蛋白(月示)和20％胎牛血清,采用单层培养法培养甘蓝夜蛾老熟幼虫的血细胞。结果原代培养仅历时35天就开始了第一次传代,共继代培养8次。细胞形态以圆形和梭形为主,圆形细胞直径为20～31μm,梭形细胞大小为18～20μm×35～50μm。利用第三代培养的细胞悬液,以3.5×10~5cells/ml浓度培养,其群体倍增时间约60小时。核型分析表明,细胞的染色体约呈圆球形,数目变化较大。经聚丙烯酰胺凝胶电泳分析,细胞的酯酶同功酶带为12条,其中有6条主带。培养的细胞于4℃直接冷冻保存可长达70天。     

棉铃虫猖獗原因及治理对策

我县1990年以前,棉花种植面积一般都在1333．33～1533．33hm2之间。当时棉铃虫属偶发性害虫,为害较重的1984年,皮棉损失38．4kg／667m2。进人叨年代,我县棉花种植面积大幅度增加,棉铃虫开始成为棉花上主要害虫,为害面积占棉花种植面积的95％以上,尤其是1990、1991和1995年,因棉铃虫为客每667m2损失皮棉分别为67．5、563和45Kg。在棉铃虫大发生的7、8月份,每百株棉花有棉铃虫幼虫35～45头。棉铃虫的为害已成为影响棉花生产的一重要因素。近年来,新一轮产业结构的调整为棉铃虫的发生为害提供了非常有利的条件,本文拟根据该早自身…     

棉花中5-羟色胺含量的时空动态及其对棉铃虫生长发育的影响

为明确棉花中5-羟色胺含量的时空动态及其对棉铃虫Helicoverpa armigera生长发育的影响,采用高效液相色谱方法检测不同棉花品种(系)中5-羟色胺含量的时空动态,并以添加外源5-羟色胺的人工饲料饲喂棉铃虫,分析5-羟色胺对其生长发育的影响。结果表明,不同棉花品种(系)叶片中5-羟色胺的含量为5.0～20.8μg/g,其中蕾期与花期棉株叶片中5-羟色胺的含量均高于苗期与铃期棉株叶片,除个别品种(系)外差异均达显著水平。饲喂添加外源5-羟色胺的人工饲料可导致棉铃虫化蛹提前、发育历期缩短以及蛹重增加。10μg/g和100μg/g的5-羟色胺对棉铃虫幼虫的死亡率或没有影响或降低死亡率,但是极高浓度(500μg/g和1 000μg/g)的5-羟色胺能够提高棉铃虫幼虫的死亡率。表明常规棉花蕾期与花期较高含量的5-羟色胺可能有利于棉铃虫的生长发育,在抗虫品种(系)培育中可将低5-羟色胺含量作为抗虫种质资源的参考指标。     

华北北部地区二代棉铃虫成虫迁飞行为的雷达观测

迁飞习性是棉铃虫区域性灾变的生物学基础,明确棉铃虫的迁飞行为对发展预警技术有重要的意义.2000年7～8月华北地区棉铃虫大发生期间,利用昆虫雷达和空中诱虫灯在河北省廊坊市观测研究了棉铃虫成虫的迁飞行为.试验结果表明,与地面棉铃虫相比,高空棉铃虫具有明显的迁飞昆虫生理特征.棉铃虫成虫一般在日落后30 min（20：00）左右大量起飞,种群密度在1 h后达到峰值.此后,随着成虫的大量迁出,空中密度逐渐下降.棉铃虫成虫从低空到高空起飞过程中位移方向多呈顺时针旋转,借助夏季盛行风飞行.成虫飞行成层多集中在200～300m高度,最高可达1000 m.多数个体位移速率35～45 km/h,整个夜间的迁移活动持续7～8 h,迁移距离大约250～450km.     

狭叶菖蒲乙醇提取物对棉铃虫卵和幼虫的生物活性

为筛选安全高效的棉铃虫防治药剂,选用狭叶菖蒲Acorus calamus var.angustatus乙醇提取物对棉铃虫Helicoverpa armigera卵和幼虫的触杀活性、胃毒作用、拒食效果和生长抑制作用进行了测定,同时以0.5%藜芦碱为药剂对照,对比分析狭叶菖蒲提取物的杀虫效果。结果表明,狭叶菖蒲乙醇提取物对棉铃虫3龄幼虫有显著的触杀、胃毒、拒食和生长抑制活性以及杀卵效果,且生物活性随浓度升高和处理时间延长而增加;狭叶菖蒲提取物对棉铃虫触杀活性、胃毒活性、杀卵活性的致死中浓度LC_(50)分别为20.50、19.26和31.39 mg/m L,对棉铃虫生长抑制中浓度EC_(50)和拒食中浓度AFC_(50)分别为7.15、10.43 mg/m L;0.5%藜芦碱药剂对棉铃虫触杀活性、胃毒活性和杀卵活性LC_(50)分别为12.19、16.90和29.87 mg/m L,对棉铃虫EC_(50)和AFC_(50)分别为3.99、8.32 mg/m L,均低于菖蒲根茎提取物。气相色谱-质谱分析结果显示,狭叶菖蒲乙醇提取物主要成分为α-细辛醚、β-细辛醚、菖蒲酮和白千层醇。表明狭叶菖蒲乙醇提取物有开发为新型植物源农药的潜力。     

柑桔大实蝇辐射不育机理的研究

本文研究了柑桔大实蝇蛹的发育,生殖系统和生殖细胞的发生及辐射对卵子、精子及其超微结构的影响。后期蛹体细胞分化发育完成时,卵子尚处于卵原囊期,雄虫已形成大量成熟精子。用9krad照射后期蛹,不影响成虫的活动和交尾竞争能力,但可导致大实蝇不育。大实蝇染色体数目为2n=12,总长度56.2μm,长度变异范围6.52～1.10μm,属中等非对称核型。辐照后引起染色体断裂而导致缺损、多着丝点环等畸变,使细胞分裂受阻引起不育。唾腺及肠细胞辐照以后24小时DNA含量明显下降,但能逐步修复。     

理化诱控集成技术综合防控棉田棉铃虫效果观察

2013—2014年在昌吉州开展了理化诱控集成技术综合防控棉田棉铃虫试验示范。结果表明,理化诱控技术集成应用防控棉铃虫,田间百株卵量平均降低58.9%,百株幼虫量平均降低55.3%,平均防效为66.3%。与不防治田块相比,籽棉平均增产23.9 kg/667m2,净收益增加120.1元/667m2。     

Relationship between the Spray Droplet Density of Two Protectant Fungicides and the Germination of Mycosphaerella fijiensis Ascospores on Banana Leaf Surfaces

The effect of fungicide spray droplet density (droplet cm^-2), droplet size, and proximity of the spray droplet deposit to fungal spores was investigated with Mycosphaerella fijiensis ascospores on the banana (Musa AAA) leaf surface for two contact fungicides: chlorothalonil and mancozeb. When droplet size was maintained at a volume median diameter (VMD) of 250 μm while total spray volume per hectare changed, M. fijiensis ascospore germination on the leaf surface fell below 1% for both fungicides at a droplet deposit density of 30 droplet cm^-2. At a droplet deposit density of 50 droplet cm^-2, no ascospores germinated in either fungicide treatment. When both droplet size and droplet cm^-2 varied while spray volume was fixed at 20 litre ha^-1, ascospore germination reached 0% at 10 droplet cm^-2 (VMD=602 μm) for both fungicides. At lower droplet densities (2–5 droplet cm^-2 VMD=989 μm and 804 μm respectively), ascospore germination on the mancozeb-treated leaves was significantly lower than on the chlorothalonil-treated leaves. The zone of inhibition surrounding a fungicide droplet deposit (VMD=250 μm) on the leaf surface was estimated to extend 1·02 mm beyond the visible edge of the spray droplet deposit for chlorothalonil and 1·29 mm for mancozeb. The efficacy of fungicide spray droplet deposit densities which are lower than currently recommended for low-volume, aerial applications of protectant fungicides was confirmed in an analysis of leaf samples recovered after commercial applications in a banana plantation. Calibrating agricultural spray aircraft to deliver fungicide spray droplets with a mean droplet deposit density of 30 droplet cm^-2 and a VMD between 300 and 400 μm will probably reduce spray drift, increase deposition efficiency on crop foliage, and enhance disease control compared to aircraft calibrated to spray finer droplets. © 1997 SCI.     

The effect of molasses on the evaporation and impaction of spray droplets

The addition of 20% molasses to water did not reduce the rate of evaporation of water from spray droplets. The 20% molasses droplets evaporated at the same rate as water droplets until ca 20% of their volume was left. When sprayed under field conditions at 30% relative humdity (r.h.) the volume median diameter (v.m.d.) of the 20% molasses spray (132 μm) was larger than the v.m.d. of the water spray (116 μm) and more droplets smaller than 19 μm were captured on magnesium oxide slides than with the water spray. The addition of molasses improved the impaction efficiency of droplets by increasing their density, and increased the minimum size to which a given droplet could evaporate.     

烟蚜茧蜂畸形细胞发生及发育

烟蚜茧蜂(Aphidius gifuensis)畸形细胞来源于卵的浆膜层。蜂产卵33～36 h后幼虫孵化,每胚胎平均释放150个细胞。畸形细胞的直径随寄生日龄而增加,由初始直径(22.1±6.5)μm增长到第5天达最大为(30.1±8.5)μm。但是,其大小受多种因素影响,随寄主龄期和外界因素等不同而有差异,即使是条件相同其大小也有不同,最小的9.0μm,最大可达100.0μm,但其数目却随日龄增长而下降。扫描电镜显示:畸形细胞表面覆有微绒毛,4日龄比1日龄的更长、更密,表明吸收和分泌功能增强。     

Effets des urées substituées sur les oxydations phosphorylantes des mitochondries de tubercules de pomme de terre (Solanum tuberosum L.): comparaison avec I'action sur liposomes

L'action de 24 urées substituées et du propanil a étéétudiée sur mitochondries de tubercules de pommes de terre et sur membranes phospholipidiques artificielles (liposomes). Tous les produits sont actifs sur mitochondries á 10^?3m . Le néburun, le siduron, le chlorbromuron, le buturon, le linuron, le fenobenzuron, le monolinuron et le propanil sont découplants á 10^?4m ; le chloroxuron et le TBU agissent comme inhibiteurs du transfert d'électrons. La concentration diminuant de 50% la valeur du P/O est 50 μm pour le néburon, 65–70 μm pour le siduron, 150–200 μm pour le chlorbromuron et 100 μm pour le chloroxuron; les autres produits ont un effet moindre. Seuls les produits découplants sur mitochondries (auxquels il faut ajouter le chloroxuron) augmentent la perméabilité de la membrane des liposomes au pottassium et dans certains cas aux protons. II existe une bonne corrélation entre les activités découplantes sur mitochondries et sur liposomes. Die Wirkung substituierter Harnstoffe auf die oxidative Phosphorylierung der Mittochondrien von Kartoffelknollen (Solarium tuberosum L.). Vergleich mit der Wirkung auf Liposomen. Es wurde die Wirkung von 24 substituierten Harnstoffen und von Propanil auf Mitochondrien von Kartoffelknollen und auf künstliche phospholipidhaltige Membranen (Liposomen) untersucht. Alle Verbindungen sind bis 10^?3m auf Mitochondrien wirksam Bei 10^?4m wirken die folgenden Verbindungen als Entkoppler: Neburon, Siduron, Chlorbromuron, Buturon. Linuron, Fenobenzuron. Monolinuron und Propanil; Chlortoluron und TBU wirken wie Hemmer des Eiektronentransports Die Konzentration. die zu einer Verminderung des P/O-Werts führt, betràt 50 μm für Neburon, 65–70 μm für Siduron, 150–200 μm für Chlorbromuron und 100 μm für Chloroxuron; die anderen Verbindungen haben eine geringere Wirkung. Nur die Verbindungen. die bei Mitochondrien entkoppelnd wirken (hierzu muss auch Chloroxuron gerechnet werden) erhöhten die Permeabilität der Liposomenmembranen für Kalium und in bestimmten Fällen für Protonen. Es besteht eine gute Korrelation zwischen der entkoppelnden Wirkung bei Mitochondrien und bei Liposomen The effects of substituted urea herbicides on phosphorilant oxidations of mitochondria of potato tubers (Solanum tuberosum L.): comparisons with the effect on liposomes. The action of twenty-four substituted urea herbicides and of propanil on mitochondria of potato tubers and on artificial phospholipid membranes (liposomes) was studied. All the products were active on mitochondria at 10^?3m . At 10^?4m , neburon, siduron, chlorobromuron, buturon. linuron, fenobenzuron, monolinuron and propanil were decoupling: chlorotoluron and TBU behaved as inhibitors of electron transfer. The concentration causing 50% drop in the value of P/O was 50 μm for neburon, 65–70 μm for siduron, 150–200 μm for chloro-bronuron and 100μm for chloroxuron. The other products had less effect, Only the products decoupling on mitochondria (to which must be added chloroxuron) increased the permeability of the liposome membrane to potassium and in certain cases to protons. There was a good correlation between decoupling activity on mitochondria and on liposomes. ? Avec la collaboration technique de J. L. Dufour. Abréviations utilisées. ADP; adénosine 5’diphosphate; ATP: adénosine 5’triphosphate; SAB: sérum albumine bovine; EDTA: acide éthylénediaminotétracétique; DMSO: diméthylsulfoxyde; TBU: terbutyl N 4-phényl, N'diméthylurée, R.C.R.: rapport de contrôle respiratoire.     

Preliminary studies of<Emphasis Type="Italic">in vitro</Emphasis> stimulation of sexual mating among isolates of<Emphasis Type="Italic">Mycosphaerella fijiensis</Emphasis>, causal agent of black sigatoka disease in bananas and plantains

Single-ascospore-derived isolates ofMycosphaerella fijiensis Morelet from false horn ‘Agbagba’ plantain leaves obtained from five different villages in southern Nigeria were stimulated to mate under artificial conditions. Pairs of isolates were incubated under blacklight on potato dextrose agar (PDA) with surface-sterilized plantain leaves or on PDA with autoclaved plantain leaves. Some isolates were observed to be sexually compatible by their ability to produce spherical to bulb-shaped fruiting body structures (FBS) and ascospores on pairing. FBS were observed to measure between 39–65 μm (smallest diameter) and 39–104 μm (largest diameter; mean 55.3×71.1 μm) in diameter, whereas ascospore lengths measured between 13.0 and 14.9 μm. Length of incubation time required for FBS production was dependent on the pair of isolates involved, the average being 40.1 days. With some pairs, ascospores were observed after 35 days of incubation. http://www.phytoparasitica.org posting Dec. 16, 2002.     

Fate of terbutryn in macrophyte-free and macrophyte-containing farm ponds

Terbutryn (2-ethylamino-4-(tert-butylamino)-6-methylthio-s-triazine) was applied in June 1978, to two farm ponds (A and C) near Winnipeg. Canada, to give 100 μg/l water concentrations. The persistence of the herbicide and its degradation products was monitored over a 61-week period following application. The half-life of terbutryn m the water column ranged from 3 weeks in Pond C, which contained heavy growths of cattails (Typha sp.) and duckweed (Lemna sp.), to 30 days in Pond A. which was free from aquatic macrophytes, Terbutryn residues m sediment reached a maximum of 1.4 μg/g (dry wt) in Pond A and 0.5 μg/g in C. Maximum concentrations of N-deethylated terbutryn (2amino-4-(tert-butylamino)-6-methylthio-s-tria-zine)(DET) were 14.4 μg/l in Pond A water after 61 weeks and 0.14 μg/g in Pond C sediment after 30 weeks. The maximum concentration of hydroxy-terbutryn (2-hydroxy-4-ethyl-amino-6-(tert-butylamino)-s-triazine) (HT) observed in pond water was 6.4 μg/l in Pond C after 7 weeks. HT was not detected in sediment (<0.05 μg/g) during the study. After 61 weeks, about 50% of the terbutryn that was added could still be accounted for in Pond A and 35% in Pond C. Terbutryn. DET and HT represented an estimated 71, 28 and 1%, respectively, of total terbutryn remaining in Pond A and 65, 29 and 6%, respectively, of that remaining in Pond C, 61 weeks after application, Terbutryn residues in Typha ranged from 0.3 μg/g (dry wt) in the shoot to 3.3 μg/g in the roots. After 12 weeks, terbutryn residues in plants (Pond C) were estimated to account for 1 to 4% of the herbicide in the pond.     

进境日本罗汉松上可可花瘿病菌的截获鉴定

 目前,该病菌已被列入我国进境植物检疫性有害生物名录,是一种检疫性植物病原真菌。该病菌分布广泛,侵染可可造成癌肿病,严重时可导致可可绝收\[2\],也能够引起多种植物顶枯病的发生,在日本有该菌造成释迦顶枯病的报道\[3\]。2013年3月,宁波检验检疫局从日本进境罗汉松种苗上分离到一株疑似可可花瘿病菌的分离物,通过形态学特征观察、致病性测定和序列比对分析,对其进行了鉴定,现报道如下。     

A comparison of the efficiency of sprays of two drop-size ranges in an apple orchard

A two-season trial of a mist blower-sprayer with improved air-flow characteristics was made to assess the relative efficiency of 120 and 180 μm mass median diameter (MMD) drop-size sprays for the control of apple powdery mildew (Podosphaera leucotricha) and fruit tree red spider mite (Panonychus ulmi Koch) in a hedgerow-type apple orchard. The principal pesticide was binapacryl, applied at two rates for each drop-size. Under typical commercial conditions the smaller drop-size approximately halved the incidence of apple mildew found when the conventional 180 μm MMD drop-size spray was used; there was no conclusive advantage against red spider mite. Unexpectedly large variations occurred in the deposits from the weekly applications and were related to the humidity during spraying.     

Investigation of the Mode of Action of Nematode Neuropeptides

The neuropeptide AF2 has a complex set of actions on the dorsal muscle strip of Ascaris suum, including a potentiation of the acetylcholine-stimulated muscle contraction. Caffeine at 100 μm and 5 mm inhibited this potentiation, as did 100 μm theophylline in two out of six studies. The cyclic-AMP-potentiating compounds IBMX, dibutyryl cAMP and forskolin had no effect on the AF2-induced potentiation of the acetylcholine-stimulated muscle contraction. These preliminary data suggest that the potentiating action of AF2 is not mediated by a cAMP pathway.     

10th British Weed Control Conference

The performance of different spray droplet spectra of cypermethrin from cone nozzles applied to brassica leaves was evaluated by bioassay using Plutella xylostella larvae. A spray droplet spectrum containing small droplets (VMD = 119 μm) caused a significantly higher knockdown and mortality compared to a coarser spray (VMD = 210 μm). No significant difference in the responses was observed when cypermethrin was sprayed over the top of the plants compared to plants sprayed from both sides using either nozzle; but the fine spray consistently gave better knockdown and mortality regardless of spray direction. The results indicated that spray effectiveness of cypermethrin could be improved by using a fine spray nozzle.