不同LED单波长杀虫灯对玉米-大豆带状套作模式内主要害虫的诱杀效果

【目的】针对害虫对不同波长光的趋性,筛选适合诱杀玉米-大豆带状田主要害虫的LED单波长杀虫灯,并探寻其应用模式,提高防虫效果,减少对天敌昆虫的影响。【方法】以复合波长LED杀虫灯为对照,调查13个单波长LED杀虫灯在玉米-大豆带状套作全生育期内诱杀的害虫种类和数量,并监测害虫发生动态。【结果】筛选获得385、389、395、403、407 nm 5个单波长LED杀虫灯,对套作田内桃蛀螟DichocrocispunctiferalisGuenée、斜纹夜蛾SpodopteralituraFabricius、暗黑鳃金龟Holotrichia parallela Motschulsky、小黄鳃金龟Metabolus flavescens Brenske和蝽科Pentatomidae害虫的诱杀效果较好,且与复合波长LED杀虫灯相比对天敌昆虫和中性昆虫的影响小。【结论】套作栽培下主要害虫的防治需结合害虫发生动态,适时使用5种杀虫灯,从而达到最大防控效果,这为合理利用LED单波长杀虫灯监测和防控玉米-大豆带状套作栽培主要害虫提供了重要参考。     

重点单项诱杀措施复合配置对棉铃虫的诱杀效果及规格比较

不同灯光与性诱剂或杨树枝把的复合配置处理对棉铃虫Helicoverpa armigera成虫均具有较明显的诱杀作用,其各自的田间控制效果各不相同,且明显与棉铃虫田间实际发生的相对程度有关。在一定范围内,棉铃虫发生量大的世代或年份,控制效果较好,发生量超常大时控制效果有所降低。综合分析比较该几种复合配置诱集源处理的诱蛾量、田间百株卵量、幼虫量及其对棉铃虫有效态天敌量的影响等因素,结果显示：在不同灯光与性诱剂或杨树枝把的复合配置处理中,以高压汞灯和性诱剂复配效果最好,双波灯与性诱剂的复配效果稍差。高压汞灯与性诱剂、双波灯与性诱剂复配处理区的百株卵量在160 m内分别比对照降低34.5%、28.6%。性诱剂宜设置于高压汞灯区外围80—160 m外,以形成两者空间和时间上的互补。     

昆虫DNA条形码分析中的距离方法

本文介绍了DNA条形码分析中常用的距离方法,包括简单的距离方法、基于阈值的距离方法和基于模糊成员关系的距离方法,并且以松毛虫属7个近缘种的COⅠ数据为例,运用基于阈值的距离方法进行演示分析。     

盛夏西湖龙井茶园色板诱杀的昆虫类群的组成及其趋色性差异

探讨减免施药,代之以诱虫板有效诱杀西湖龙井茶园重要害虫,并避免误伤天敌。遂选一大片西湖龙井茶园,于茶园昆虫类群繁盛的7月下旬,连续72 h用芽绿和素馨黄等12种诱虫板诱捕昆虫,解析被捕昆虫的类群组成及其趋色性差异。结果：（1）捕获253870头昆虫,隶属于147种57科8目,半翅目、膜翅目和双翅目是优势类群,依次占总个体数的98.8%、0.6%和0.5%;害虫、天敌和中性昆虫种数分别为61、54和32;（2）黑刺粉虱和茶小绿叶蝉占总个体数94.1%和2.0%;（3）平均每块芽绿、素馨黄色板诱捕茶小绿叶蝉和黑刺粉虱分别是86头和10410头;（4）平均每块墨绿、桃红、天蓝、湖蓝、紫色和纯白色板诱杀的个体数< 400、诱杀的种数≤10、天敌/害虫个体数之比在1/10和1/40之间,被捕昆虫的群落多样性指数H''>1.0;平均每块大红、果绿色板诱杀的个体数 > 450且 < 800、诱杀的种数 > 9且 < 10,天敌/害虫个体数之比值介于1/85和1/45间,0.5 < H'' < 0.7;平均每块桔黄、土黄、芽绿和素馨黄色板诱杀的个体数>3700头、诱捕的种数≥10、天敌/害虫个体数之比<1/100,多样性指数H''<0.5;（5）芽绿、素馨黄、土黄和桔黄诱杀害虫个体数极显著大于其它8种色板诱杀的害虫个体数。认为：在西湖龙井茶园盛夏3日就可诱杀极多昆虫,既说明茶园昆虫种类多且个体数大,又揭示茶园优势种害虫茶小绿叶蝉和黑刺粉虱具有显著趋黄绿色习性,可分别使用芽绿、素馨黄色板诱杀之,还能尽量减少天敌和中性昆虫被误杀,部分地替代化学防治。     

雷达观测空中飞行昆虫的有效距离

以包覆细铜纱网的乒乓球作为标准检测目标,检测了X-频带,波长3cm的公主岭昆虫雷达观测空中飞行昆虫的有效距离。检测到乒乓球回波的最远距离为5185.6m;计算观测个体粘虫Mythimnaseparata（Walker）的最远有效距离约为2000m,观测个体褐飞虱Nilaparvatalugens（Stal）的最远有效距离的为300m。该雷达适于观测粘虫等体重几十mg的昆虫在空中的飞行动态。     

棉铃虫Helicoverpa armigera的环境友好型诱杀技术研究

2003年和2004年,在山东惠民采用杀虫灯、性诱剂、杨树枝把等措施开展了诱杀棉铃虫Helicoverpa armigera成虫的防治试验.杀虫灯+10支性诱剂,杀虫灯+5支性诱剂+5支杨树枝把,杀虫灯+lO支杨树枝把,杀虫灯4种措施的日均诱蛾量分别为11.4、10.4、8.6和7.0头,性诱剂和杨树枝把均未显著提高对棉铃虫的诱杀效果.不同诱捕方案对棉铃虫累积诱蛾量随日期的变化符合Gompertz方程.普通灯和时控灯对棉铃虫的日均诱蛾量分别为19.9头和17.4头,二者差异不显著;时控灯对异色瓢虫和龟纹瓢虫的日均诱捕量均少于普通灯;减少开灯时间可在不显著降低棉铃虫诱杀量的同时,有效保护捕食性瓢虫.与普通灯相比,设置时间合理的时控灯(夜间19:00～23:00和3:00～5:00开灯)未显著降低棉铃虫的日均诱蛾量,而对异色瓢虫和龟纹瓢虫的日均诱捕量分别为2.0头和4.9头,均显著低于普通灯的3.7头和9.2头,合理设置开关灯控制模式可在不显著降低对棉铃虫诱杀效果的同时,降低近50%的天敌杀伤率,节约用电40%.     

昆虫趋光的性别差异及其影响因素

趋光是众多夜行性昆虫的主要行为特征之一.研究表明: 许多夜行性昆虫的趋光存在明显的性别差异现象,而这种差异受多种因素的影响.本文从雌雄成虫飞行能力差异导致其飞行距离与高度的不同、雌雄成虫复眼结构差异导致其对光源反应不同,以及雌雄成虫对光源和环境刺激的敏感性不同等方面综述了导致昆虫趋光性别差异的因素,并探讨了昆虫趋光性别差异的应用及今后研究方向.     

江西新岗山森林昆虫种内遗传距离研究

DNA条形码目前广泛用于昆虫多样性研究。本研究采用DNA条形码（即线粒体细胞色素c氧化酶亚基I基因COI 5′端）,通过比较所获分子分类操作单元（Molecular operational taxonomic units,MOTU）的种内遗传距离,探究DNA条形码在亚热带森林（位于我国江西省新岗山）不同昆虫类群中的物种鉴定和界定效用。数据分析中结合数据库比对信息,采用jMOTU、ABGD、bPTP、GMYC 这4种物种界定方法获得MOTU,从而开展种内遗传距离分析。本研究共挑选出479个昆虫样本,获得475条COI序列,经NCBI、BOLD在线数据库比对属于6个目,与形态初步划分一致;物种界定分析获得288个MOTU,其中鳞翅目最多,达85个,膜翅目、双翅目、半翅目、鞘翅目次之,分别为80、74、21和20个,直翅目最少,仅8个。膜翅目和双翅目的种内遗传距离均值及标准偏差较大（膜翅目：0.89%±0.87%;双翅目：0.73%±0.58%）,鳞翅目的最小（0.28%±0.20%）。研究表明：不同昆虫类群的种内遗传距离虽然整体在一定范围,但仍然存在一定的差异,因此不能笼统地依靠遗传距离的距离阈值进行物种划分;现有数据库需要补充足够的昆虫物种信息,才能提升物种鉴定效率。本研究丰富了亚热带森林昆虫分子数据库,同时也为进一步探索基于分子分类学开展昆虫多样性研究提供了基础数据和参考。     

分子生态学重要概念——遗传距离及其测度的理论研究概况

综述了遗传距离的概念、背景,有关遗传距离的几种基本的突变模型以及和遗传距离有关的参量和几种常用统计量,指出在处理蛋白质数据、分子数据以及序列数据时,如何选择相应的统计量和可用的软件包,同时还着重指明了各种模型的假设前提,为处理实际的蛋白质或分子数据时选择合适的模型,和对数据的最终解释提供一些帮助。     

Why Bacillus thuringiensis insecticidal toxins are so effective: unique features of their mode of action

The spore-forming bacterium Bacillus thuringiensis produces intracellular inclusions comprised of protoxins active on several orders of insects. These highly effective and specific toxins have great potential in agriculture and for the control of disease-related insect vectors. Inclusions ingested by larvae are solubilized and converted to active toxins in the midgut. There are two major classes, the cytolytic toxins and the delta-endotoxins. The former are produced by B. thuringiensis subspecies active on Diptera. The latter, which will be the focus of this review, are more prevalent and active on at least three orders of insects. They have a three-domain structure with extensive functional interactions among the domains. The initial reversible binding to receptors on larval midgut cells is largely dependent upon domains II and III. Subsequent steps involve toxin insertion into the membrane and aggregation, leading to the formation of gated, cation-selective channels. The channels are comprised of certain amphipathic helices in domain I, but the three processes of insertion, aggregation and the formation of functional channels are probably dependent upon all three domains. Lethality is believed to be due to destruction of the transmembrane potential, with the subsequent osmotic lysis of cells lining the midgut. In this review, the mode of action of these delta-endotoxins will be discussed with emphasis on unique features.     

Synthesis and insecticidal evaluation of novel anthranilic diamides containing N-substitued nitrophenylpyrazole

To cope with developing pest resistance and ecological problems associated with conventional insecticides and to search for potent insecticides targeting at ryanodine receptor (RyR), a series of novel anthranilic diamides containing N-substitued nitrophenylpyrazole were designed and synthesized. The insecticidal activities of target compounds against oriental armyworm (Mythimna separata) and diamondback moth (Plutella xylostella) were evaluated in our greenhouse by bio-assay tests and the relative structure–activity relationships were briefly discussed. Most compounds exhibited moderate to high activities, in which G₇ and K₅ showed high activity against oriental armyworm and K₂ and K₄ against diamondback moth even better than the control-chlorantraniliprole. The calcium imaging technique was used to investigate the effects of several typical title compounds on the [Ca²⁺]_i, especially the effects of G₇ on the intracellular calcium ion concentration ([Ca²⁺]_i) in neurons, which indicated that some title compounds were potent activators of the RyR.     

Synthesis of andrographolide-related esters as insecticidal and acaricidal agents

In continuation of our program aimed at the development of natural product-based pesticidal agents, a series of andrographolide-related esters, such as 3,19-dialkyl(aryl)carbonyloxy andrographolide (3a–g), 3-alkyl(aryl)carbonyloxyandrographolide (4a–g), and 19-alkyl(aryl)carbonyloxyandrographolide (5a–g), were prepared. Their structures were well characterized by ¹H NMR, IR, optical rotation, HRMS and mp. Especially three-dimensional structures of compounds 3a, 4g, and 5g were unambiguously confirmed by single-crystal X-ray diffraction. Compounds 3a and 5a exhibited good insecticidal and acaricidal activities against Mythimna separata and Tetranychus cinnabarinus. Their structure-activity relationships were also discussed.     

Synthesis of novel quinolinomatrine derivatives and their insecticidal/acaricidal activities

In continuation of our program to discover natural product-based pesticidal agents, a series of new quinolinomatrine derivatives were prepared. Especially three-dimensional structures of five compounds were unambiguously determined by single-crystal X-ray diffraction. Among them, 21-chloroquinolinomatrine exhibited good insecticidal and acaricidal activities against two crop-threatening insect pests, Mythimna separata and Tetranychus cinnabarinus. Their structure-activity relationships were also discussed.     

Natural products-based insecticidal agents 4. Semisynthesis and insecticidal activity of novel esters of 2-chloropodophyllotoxin against Mythimna separata Walker in vivo

By using podophyllotoxin as a lead compound, eight novel esters of 2-chloropodophyllotoxin were designed, semisynthesized, and preliminarily evaluated for their insecticidal activity against the pre-third-instar larvae of Mythimna separata Walker in vivo for the first time. Among all the tested compounds, especially three esters of 2-chloropodophyllotoxin 8a, 8c, and 8g, and one intermediate 6 showed more promising and pronounced insecticidal activity than toosendanin, a commercial insecticide derived from Melia azedarach.     

Natural-product-based insecticidal agents 14. Semisynthesis and insecticidal activity of new piperine-based hydrazone derivatives against Mythimna separata Walker in vivo

In continuation of our program aimed at the discovery and development of natural-product-based insecticidal agents, twenty-six new piperine-based hydrazone derivatives were synthesized from piperine, an alkaloid isolated from Piper nigrum Linn. The single-crystal structures of 6c, 6q and 6w were unambiguously confirmed by X-ray crystallography. Their insecticidal activity was evaluated against the pre-third-instar larvae of Mythimna separata Walker in vivo. Especially compounds 6b, 6i and 6r, the final mortality rates of which, at the concentration of 1 mg/mL, were 62.1%, 65.5% and 65.5%, respectively, exhibited more pronounced insecticidal activity compared to toosendanin at 1 mg/mL, a commercial botanical insecticide isolated from Melia azedarach. It suggested that introduction of the substituents at the C-2 position on the phenyl ring of the hydrazone derivatives was important for their insecticidal activity.     

Synthesis,insecticidal activities and SAR of novel phthalamides targeting calcium channel

In order to find novel and environmental friendly insecticides targeting the ryanodine receptor, three series of novel phthalamides containing heptafluoroisopropyl group, low fluorine atoms group and non-fluorine group were designed and synthesized. 35 novel structures of three series were obtained. Insecticidal activities of title compounds against oriental armyworm (Mythimna separata) and diamondback moth (Plutella xylostella) indicated that most of title compounds showed moderate to high activities at the tested concentration. The structure–activity relationship (SAR) was discussed in detail. During synthesizing title compounds B₈, C₇, D₁, D₉ and D₁₂, their corresponding positional isomers (B₈′, C₇′, D₁′, D₉′ and D₁₂′) were afforded, and their structures were confirmed by 2D NMR. The calcium-imaging technique was also applied to investigate the effects of compounds B₂, B₁₀, C₄ and C₅ on the intracellular calcium ion concentration ([Ca²⁺]_i), which indicated that they released stored calcium ions from endoplasmic reticulum, which denoted that some compounds are potential modulators of the insect ryanodine receptor (RyR).     

Natural products-based insecticidal agents 9. Design, semisynthesis and insecticidal activity of 28-acyloxy derivatives of toosendanin against Mythimna separata Walker in vivo

In continuation of our program aimed at the discovery and development of natural products-based insecticidal agents, twelve 28-acyloxy derivatives of toosendanin (2a-l) were semisynthesized and preliminarily evaluated their activity against the pre-third-instar larvae of Mythimna separata Walker in vivo at the concentration of 1 mg/mL. Some compounds exhibited the potent insecticidal activity. Especially compounds 2c and 2j displayed the more promising insecticidal activity than their natural precursor, toosendanin, a commercial insecticide derived from Melia azedarach at 1 mg/mL. In general, it indicated that the butanoyloxy or phenylacryloyloxy moiety at the 28-position of toosendanin was essential for the insecticidal activity.     

Synthesis of some monosaccharide-related ester derivatives as insecticidal and acaricidal agents

To develop natural-product-based pesticidal agents, a series of monosaccharide-related ester derivatives (17a–q and 18a–f), glucose (xylose)-piperic acid/piperic acid-like conjugates, were synthesized. Three-dimensional structures of compounds 17b, 17g, 17h, and 17n were unambiguously determined by single-crystal X-ray diffraction. Especially compounds 18e and 18f exhibited the most potent insecticidal and acaricidal activities against Mythimna separata and Tetranychus cinnabarinus. Their structure-activity relationships were also discussed.     

Additive effects on the improvement of insecticidal activity: Design,synthesis, and insecticidal activity of novel pymetrozine derivatives

A series of new pymetrozine analogues containing both methyl on the imine carbon and phenoxy group at the pyridine ring were designed and synthesized. Their insecticidal activities against bean aphid (Aphis craccivora), mosquito larvae (Culex pipiens pallens), cotton bollworm (Helicoverpa armigera), corn borer (Ostrinia nubilalis) and oriental armyworm (Mythimna separata) were evaluated. The results of bioassays indicated that most of the target compounds showed good insecticidal activity against bean aphid; especially, IIIf (80%) and IIIl (80%) exhibited higher aphicidal activity than pymetrozine (30%) at 5 mg/kg, and the two compounds still showed 20% and 30% mortality at 2.5 mg/kg, respectively, whereas pymetrozine displayed no activity at the same concentration. These compounds exhibited a completely different structure–activity relationship to that of known pymetrozine derivatives, in which it is thought introducing alkyl group on the imine carbon could be detrimental to the activities. Our new result suggested that the methyl on the imine carbon and phenoxy group at the pyridine ring of phenoxy group may play additive effects on the improvement of aphicidal activity. Besides this, compound IIIs, containing an allyl at the para position of phenoxy group, exhibited excellent insecticidal activity against mosquito larvae, lepidoptera pests cotton bollworm, corn borer and oriental armyworm.