温湿度对玫烟色棒束孢IF‐1106菌株孢子萌发及对烟粉虱致病力的影响(英文)

B型烟粉虱Bemisia tabaci Gennadius是一种重要的世界性农业害虫。玫烟色棒束孢Isaria fumosorosea是防治烟粉虱的一种重要的虫生真菌。对不同温度(20、23、26、29、32℃)、不同湿度(53%、65%、75%、85%、95%)下玫烟色棒束孢IF‐1106菌株分生孢子萌发及其对烟粉虱的致病力进行了测定。结果表明:温度对孢子的萌发有显著影响,26℃时孢子萌发率最高。当相对湿度低于75%时,孢子不萌发或萌发率较低;当相对湿度为85%–95%时,孢子萌发率显著升高。26℃时,烟粉虱2龄若虫的累计死亡率最高。随着相对湿度增大,病菌的致病力增强。当相对湿度为53%–95%时,烟粉虱2龄若虫累计死亡率从54.55%增加到88.89%。玫烟色棒束孢的致病力与孢子萌发率呈正相关,但温度比相对湿度对其影响更明显。结果表明,玫烟色棒束孢IF‐1106菌株侵染烟粉虱的最佳条件是温度26℃和相对湿度大于85%。     

应用虫生真菌防治烟粉虱的现状

烟粉虱Bemisia tabaci属世界性分布的大害虫.在一定条件下虫生真菌是控制烟粉虱种群的最有效天敌.本文就几种常见虫生真菌:蜡蚧轮枝菌Verticilliumlecanii、座壳孢Aschersoniaspp.、玫烟色拟青霉Paecilomycesfumosoroseus、球孢白僵菌Beauveria bassiana等防治烟粉虱的应用现状以及它们与其它天敌的关系进行了综述,以期对烟粉虱虫生真菌的合理利用提供参考.     

两种杀虫真菌制剂对茶小绿叶蝉的田间防效评价

于2002年盛夏在浙江遂昌一高山茶园对茶小绿叶蝉(Empoasca spp．)进行了真菌杀虫剂的田间药效试验。所用菌剂为球孢白僵菌(Beauveria bassiana)和玫烟色拟青霉(Paecilomyces fumosoroseus)的纯孢子悬乳剂及其与3％吡虫啉10％可湿剂的混配剂．各菌剂稀释500倍喷雾2次,间隔12d．结果表明。两种真菌的混配剂明显优于纯菌剂,其中球孢白僵菌混配剂的最高防效达83．4％,而玫烟色拟青霉的最高防效为71．3％．根据25d期间历次调查结果计算平均防效,球孢白僵菌混配剂达66．8％,玫烟色拟青霉混配剂为62．1％,含微量吡虫啉的矿物油为50．3％,球孢白僵菌和玫烟色拟青霉的纯菌剂分别为49．5％和19．0％,结合试验期间气候及田间种群结构特征,讨论了各处理问差异的来源及提高真菌杀虫剂控制茶小绿叶蝉效果的可能途径。     

两种杀虫真菌制剂与低用量吡虫啉对温室粉虱的协同防效评价

在昆明市郊蔬菜基地4间大棚(5m×100m·间^-1)栽培的生菜上,用球孢白僵菌(Beauveriabassiana)和玫烟色拟青霉(Paecilomyces fumasonoseus)的纯孢子乳悬剂(有效含孢量10^10·ml^-1)及其与1％和3％(w／v)的吡虫啉10％WP的混配剂对温室粉虱(Trialeurodes vaporariorum)进行了协同药效试验,吡虫啉添加量仅相当于推荐用量的6．4％～9．5％和19．1％～28．6％,试验含6个菌剂处理、2个低用量吡虫啉处理和1个清水对照,各有3个小区(7m×5m·小区^-1)重复,随机区组排列,稀释1000倍的菌液(含孢量10^7·ml^-1)和吡虫啉液于生菜移栽后第11d首次喷雾,15d后喷第二次,首次用菌前调查初始粉虱密度,用菌后每隔5d调查活虫数和死虫数,从8月20日起历时30d,结果表明,连续2次用菌有效地控制了粉虱对当季大棚生菜的危害,各菌剂处理的最终相对防效和虫口减退率均达到95％以上,极显著地高于低用量吡虫啉处理,其中,玫烟色拟青霉制剂对粉虱的控制效果一般优于球孢白僵菌制剂,且与吡虫啉的添加量呈正相关,但是,各菌剂处理间控虫效果的差异主要发生在首次用菌后第5d和10d,此后差异逐渐缩小,至第二次用菌后第10d各菌剂处理间无显著差异,本试验结果表明,两种真菌的孢子乳悬剂均可用于温室粉虱的防治,添加微量吡虫啉可增强菌剂的防效。     

紫外线照射对玫烟色拟青霉产孢子能力的影响

目的:探讨紫外线照射对玫烟色拟青霉产孢子能力的影响.方法:利用20W紫外 灯对玫烟色拟青霉的原生质体悬浮液进行了不同照射时间、对孢子悬浮液进行了不同照射距 离和时间组合的紫外线照射处理.结果:紫外灯下30cm照射原生质体90 s及紫外灯下20cm照射孢子20min两个处理中,菌落直径最大菌株的菌丝生长速度显著高于出 发菌株,产孢量也分别是出发菌株的1.4及1.6倍.结论:适宜的紫外线照射处理可以提高玫烟色拟青霉的产孢子能力.     

国内烟粉虱B生物型的分布及其控制措施研究

收集了国内 15个省 2 6个不同地区的烟粉虱种群 ,根据有关报道合成了一个随即引物H16 ,对不同地区的烟粉虱DNA进行了RAPD -PCR扩增 ,根据扩增结果分析了不同烟粉虱种群的生物型。结果表明 ,在以上不同省市和地区中 ,北京、山东等 11个省 19个地区都有烟粉虱B型的分布。以烟粉虱B型为防治对象 ,比较了使用高效氯氰菊酯、高效大功臣 2种化学农药 ,和应用桨角蚜小蜂、粉虱座壳孢 2种寄生性天敌 ,对黄瓜上烟粉虱种群的控制效果 ,结果表明在一个世代内 ,喷施高效大功臣 (10 0 0× ,1次 ) ,喷施粉虱座壳孢 (5× 10 6 个孢子 /ml,2次 ) ,和释放桨角蚜小蜂 (3头雌蜂 /株 ,2次 ) ,对烟粉虱种群的控制作用分别达到 78.2 1%、95 .74 %和 5 7.5 8% ,三者都可以对烟粉虱起到较好的防治效果。     

植物油与含水量对玫烟色棒束孢IfB01菌株分生孢子萌发率的影响

玫烟色棒束孢菌Isaria fumosorosea菌株If B01是本实验室分离的一株对烟粉虱Bemisia tabaci防治效果较好的虫生真菌,但其分生孢子不耐贮藏,明确不同因子对孢子萌发率的影响具有重要意义。将含水量为18.83%、9.31%和3.13%的玫烟色棒束孢菌分生孢子粉分别和大豆油、调和油、花生油、葵花籽油和玉米油充分混合,在25℃下贮藏7 d、30 d和90 d,测定分生孢子萌发率。结果表明,植物油有利于孢子贮藏,贮藏30 d后植物油处理的分生孢子萌发率高于66%,而对照的萌发率只5%左右,5种植物油之间没有显著性差异;低含水量能促进植物油贮分生孢子萌发率的提高,贮藏30 d后,含水量3.13%和18.83%的相比,前者孢子萌发率一般高出后者10%以上。实验结果对该菌株分生孢子剂型加工具有指导意义。     

虫生真菌玫烟色棒束孢Pf9606抗逆性的研究

采用凹玻片悬滴法测定了玫烟色棒束孢在高温、紫外照射、紫外保护剂和杀菌剂等逆境胁迫下分生孢子的存活率。结果表明:玫烟色棒束孢Pf9606分生孢子在36～45 ℃高温下连续处理24 h后,该菌孢子几乎不能存活;36～45 ℃短时高温处理后,随温度的升高和处理时间的延长,孢子存活率明显降低;随紫外照射时间的延长,玫烟色棒束孢孢子存活率明显降低,当紫外照射50 s时,孢子存活率为55.33%,当照射时间延长为180 s时,孢子不能存活;不同浓度的抗坏血酸和高浓度的荧光素钠可提高玫烟色棒束孢抗紫外照射能力,抗坏血酸的理想浓度为0.2 mg/mL,荧光素钠的理想浓度为0.9 mg/mL,而不同浓度的刚果红和氧化锌对玫烟色棒束孢没有保护作用;玫烟色棒束孢与杀菌剂72%农用硫酸链霉素、70%代森联和58%甲霜灵锰锌混用后,对该菌孢子存活影响较小,不同浓度下孢子存活率均达85%以上,而常规浓度的氟吗·锰锌对玫烟色棒束孢孢子存活有较强的抑制作用。     

连栋大棚内辣椒烟粉虱的绿色防控研究

为探讨连栋大棚内蔬菜上烟粉虱的绿色防控,系统研究了芹菜不同种植方式(辣椒与芹菜按5∶1、10∶3、15∶5、两侧各种植2行芹菜)、棚内种植蓖麻和喷施拟青霉等措施对辣椒上烟粉虱的控制作用。结果发现,辣椒和芹菜以5∶1、10∶3间作以及在辣椒行外种植2行芹菜等3种种植方式对生长中期(10月11日)的辣椒上烟粉虱均具有明显的驱避作用,其中在辣椒行外种植2行芹菜后辣椒上烟粉虱虫量较对照下降71.14%,辣椒和芹菜15∶5间作对辣椒烟粉虱没有明显的驱避作用;辣椒和芹菜以5∶1、10∶3、15∶5间作以及在辣椒行外种植2行芹菜等4种种植方式对生长中后期(11月10日)辣椒上烟粉虱均具有明显的驱避作用,和对照相比,在辣椒行外种植2行芹菜辣椒上烟粉虱虫量(3.90头/3叶)下降了64.85%。在棚内种植蓖麻后,辣椒上烟粉虱成虫和若虫的数量分别下降了62.99%和53.07%。在适宜的环境条件下,以浓度106个分生孢子/mL的孢子悬液的溶液喷雾,5∶1、10∶3间作以及在辣椒行外种植2行芹菜的种植方式,拟青霉对烟粉虱的侵染率达到了80%以上,但15∶5间作的处理与对照没有明显差异。芹菜不同种植方式对辣椒产量有一定的影响,芹菜以5∶1、5∶3和行外种2行辣椒产量明显高于10∶3和对照,两侧种2行芹菜的辣椒产量比对照高34.69%。     

玫烟色拟青霉最适液体培养条件的研究

通过对不同营养和不同培养条件下玫烟色拟青霉菌丝生物量和产孢量的研究,结果表明:葡萄糖为玫烟色拟青霉液体培养的最适碳源,蛋白胨为该菌生长的最适氮源,C/N为10∶1~20∶1最适于玫烟色拟青霉菌丝生长和产孢;25℃2、4 h全光照条件,对该菌生长和产孢均有利。接种后144~168 h时,菌丝生物量和产孢量均达到高峰,分别为31.72 mg/mL、24.62孢子/mL,为黑暗条件下的1.5倍和18.3倍,因此玫烟色拟青霉液体发酵终点应选择在接种后144~168 h为最好。     

d(CGGTGGT) forms an octameric parallel G-quadruplex via stacking of unusual G(:C):G(:C):G(:C):G(:C) octads

Among non-canonical DNA secondary structures, G-quadruplexes are currently widely studied because of their probable involvement in many pivotal biological roles, and for their potential use in nanotechnology. The overall quadruplex scaffold can exhibit several morphologies through intramolecular or intermolecular organization of G-rich oligodeoxyribonucleic acid strands. In particular, several G-rich strands can form higher order assemblies by multimerization between several G-quadruplex units. Here, we report on the identification of a novel dimerization pathway. Our Nuclear magnetic resonance, circular dichroism, UV, gel electrophoresis and mass spectrometry studies on the DNA sequence dCGGTGGT demonstrate that this sequence forms an octamer when annealed in presence of K(+) or NH(4)(+) ions, through the 5'-5' stacking of two tetramolecular G-quadruplex subunits via unusual G(:C):G(:C):G(:C):G(:C) octads.     

Nasal mites (Gamasida: Rhinonyssidae) of Paroaria coronata (Miller) (Passeriformes: Emberezidae)

With the aim of identifying the species of nasal mites of Paroaria coronata (red-crested cardinal), the nasal cavity of 40 birds were examined. The nasal mites were identified as Ptilonyssus sairae de Castro and Sternostoma pirangae Pence, with 50% and 7.5% of prevalence, respectively. This is the first record of these mite species parasitizing P. coronata. This report also amplifies the area of occurrence of S. pirangae for Brazil and that of P. sairae for Rio Grande do Sul, Brazil.     

Host-searching behavior ofVenturia canescens (Grav.) (Hymenoptera: Ichneumonidae): Superparasitism

The foraging behavior ofVenturia canescens, a solitary endoparasitoid of lepidopteran larvae, was investigated in the laboratory. FemaleVenturia canescens with a larger number of mature eggs to lay were found to have higher levels of superparasitism (measured as numbers of eggs laid per parasitized host). Increased parasitoid density was found to result in reduced levels of superparasitism by host-deprived (i.e.,undepleted) wasps. Females which had been allowed access to hosts before the experiment (depleted wasps) laid fewer eggs per parasitized host than undepleted wasps, although there was no significant difference in the levels of superparasitism among the depletion periods of 1, 2, 5, and 7 h. It was also found that an egg which was encountered less than 15 min after oviposition was much less likely to be avoided than one which was encountered after more than 15 min had elapsed.     

形宽刺甲Bioramix(Bioramix) rotundicollis(Kaszab,1940)(鞘翅目:拟步甲科:刺甲族)的再描述

2012年在西藏普兰地区采集到鞘翅目Coleoptera拟步甲科Tenebrionidae刺甲族Platyscelidini一种昆虫:形宽刺甲Bioramix(Bioramix)rotundicollis(Kaszab,1940)。鉴于原始描述过于简单,且缺少特征图和整体照片,本文对其进行了详细描述,并附有特征图和整体照片。检视标本保存于西华师范大学标本馆和俄罗斯楚瓦什国立师范大学标本馆。     

Biology of Acarophenax lacunatus (Cross & Krantz) (Prostigmata: Acarophenacidae) on Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and Cryptolestes ferrugineus (Stephens) (Coleoptera: Cucujidae)

The aim of the present study was to assess the effect of six different temperatures on the development of Acarophenax lacunatus (Cross & Krantz) using eggs of Tribolium castaneum (Herbst) and Cryptolestes ferrugineus (Stephens) as hosts. The temperature affected the development of A. lacunatus. The largest values for the progeny (19 mites in T. castaneum and 15 mites in C. ferrugineus) were obtained at about 30 degrees C, as also observed for the net reproductive rate (Ro), which revealed that the A. lacunatus population increased 18 times in T. castaneum and 14 times in C. ferrugineus in a generation. The intrinsic rate of increase (r m) gradually increased with temperature, reaching the maximum value at 35 degrees C in T. castaneum (1,608) and C. ferrugineus (1,289). The generation time was negatively correlated with temperature, ranging from 1,60 to 4,85 days in T. castaneum and from 1,96 to 5,34 days in C. ferrugineus. These results suggest that the mite A. lacunatus may be used in programs of biological control of T. castaneum and C. ferrugineus in the tropics.     

Interaction between Acarophenax lacunatus (Cross & Krantz) (Prostigmata: Acarophenacidae) and Anisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae) on Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae)

The interaction between Acarophenax lacunatus (Cross & Krantz) and Anisopteromalus calandrae (Howard) may be a promising tool for the integrated pest management of stored grain insect pests. The objective of this study was to evaluate the compatibility of these two natural enemies on Rhyzopertha dominica (Fabricius). The experimental units were petri dishes (140 x 10 mm) containing 30 g of whole wheat grains (13% water content) infested with 20 adults of R. dominica. The treatments consisted of inoculation of A. lacunatus and A. calandrae, separately and associated, in eight replicates. Three inoculations of five adult females of the natural enemies were carried out in each petri dish at five, ten and fifteen days after the infestation of R. dominica. All treatments were stored during 60 days in environmental chamber at 30 +/- 1 degrees C, 60 +/- 5% relative humidity and 24 h scotophase. The smallest numbers of physogastric females of A. lacunatus and of adults of A. calandrae were obtained when the natural enemies were in association. The use of A. calandrae alone demonstrated a low instantaneous rate of increase (r(i)) of R. dominica and a high protection of the wheat grains. The association of A. calandrae with A. lacunatus led to the lowest number of immatures of R. dominica. These results demonstrate the importance of this interaction as a tool of for the integrated management of R. dominica in stored wheat grains.     

Astronotus ocellatus (Cichlidae:Pisces) and Macropodus opercularis (Anabatidae:Pisces) as predators of immature Aedes fluviatilis (Diptera:Culicidae) and Biomphalaria glabrata (Mollusca:Planorbidae).

Two fish species, Astronotus ocellatus (Cichlidae) and Macropodus opercularis (Anabatidae) were tested for predacious behavior toward immature mosquitoes (Aedes fluviatilis, Diptera:Culicidae) and schistosomiasis snail hosts (Biomphalaria glabrata, Mollusca:Planorbidae), in the presence or absence of non-living food and in laboratory conditions. A. ocellatus, a species indigenous to Brazil, was a very efficient predator of both organisms (alpha = 0.05); M. opercularis, an exotic species, preyed well on immature mosquitoes, but small snails and snail egg-masses were ingested only irregularly. Both fish species seemed to prefer live to non-living food.