Field evaluations of insecticide treatment regimens for control of the common bed bug,Cimex lectularius (L.)

BACKGROUND: Because bedbugs, Cimex lectularius L., have not been a problem in the USA for over 40 years, few insecticide products are labeled for their control. Most products that are labeled for bedbugs are pyrethroids. However, recent studies indicate that field‐collected bedbugs may be resistant to pyrethroids. There are also non‐pyrethroid products labeled for bedbugs, but, like the pyrethroids, none of these products has been evaluated for field efficacy. This study evaluated the efficacy of two insecticide treatment regimens for bedbugs in multi‐unit housing. Both of the treatments included multiple products currently being used by the pest management industry. RESULTS: The ‘traditional’ treatment consisted of applications of pyrethroid products and an insect growth regulator. The ‘novel’ treatment consisted of applications of non‐pyrethroid products. The traditional treatment significantly reduced the number of bedbugs from 39.8 ± 10.1 per unit prior to treatment to 2.2 ± 1.0 at the end of the test period (P = 0.02; 95% reduction). The number of live bedbugs in the ‘novel’ treatment was also significantly reduced from 71.4 ± 25.3 bedbugs per unit to 10.2 ± 4.4 after 8 weeks (86% population reduction). CONCLUSIONS: Although both treatment regimens reduced bedbug numbers, the fact that bedbugs were not eliminated after multiple applications suggests that the insecticides, applied at the current label rates, were inadequate. These results suggest that a more integrated approach to bedbug control is necessary in multi‐unit housing situations. Copyright © 2008 Society of Chemical Industry     

Effects of juvenile hormone analog formulations on development and reproduction in the bed bug Cimex lectularius (Hemiptera: Cimicidae)

BACKGROUND: Bed bugs (Cimex lectularius L.) have become a common insect pest in urban areas and are often difficult to manage. Eradication is made more problematic by widespread insecticide resistance, raising interest in alternative control products. Juvenile hormone analogs (JHAs) such as methoprene and hydroprene are relatively harmless to non‐arthropods and have proved to be effective against other urban insect pests. Two JHA products (Gentrol^® and Precor^®, Central Life Sciences, Schaumburg, IL) were tested for efficacy against various bed bug stages as direct spray and as dry residue using three bed bug strains. RESULTS: At 1× and 2× the label rate, Precor^® [active ingredient (S)‐methoprene] had no significant effect on the development or fecundity of bed bugs. At 2× the label rate, confinement to residues of Gentrol^® [active ingredient (S)‐hydroprene] had no significant effect, but residues at 3× and 10× the label rate caused a reduction in fecundity and impaired development. Field strains were more susceptible to the reproductive effects of (S)‐hydroprene than a long‐maintained laboratory strain. CONCLUSIONS: While JHAs are attractive alternatives for pest management because of their inherent safety and distinct mode of action, these JHA formulations would have little impact on bed bug populations without relabeling to allow for higher application rates. Copyright © 2012 Society of Chemical Industry     

水稻热休克蛋白HSP70基因克隆、表达分析及原核表达

为明确水稻热休克蛋白70（heat shock protein 70,HSP70）基因在逆境胁迫下的表达特征,以日本晴粳稻水稻品种为材料,通过基因克隆方法获得水稻HSP70基因cDNA全长序列,并采用生物信息学的方法分析其序列特征,利用实时荧光定量PCR（quantitative real-time PCR,RT-qPCR）技术测定不同水稻组织、不同激素、不同温度以及不同逆境下HSP70基因的相对表达量,同时对其原核表达条件进行优化。结果表明,水稻HSP70基因全长1 950 bp,预测蛋白大小为71.18 kD,等电点为5.10,亚细胞定位于细胞质内,有较强的亲水性。水稻HSP70蛋白序列与香蕉HSP70蛋白序列的亲缘性较高;水稻HSP70基因表达具有组织特异性,在茎中的相对表达量最高,在根中最低;低温胁迫后,水稻HSP70基因在12 h内基因相对表达量相对稳定,在24 h时相对表达量达到峰值,为9.60;高温胁迫后,在较短时间内水稻HSP70基因显著上调并达到峰值,为79.10;激素吲哚乙酸、脱落酸和油菜素内酯均能诱导水稻HSP70基因表达;但在甘露醇模拟干旱和NaCl盐胁迫处理下,水稻HSP70基因的相对表达量呈现先升后降的趋势。水稻HSP70蛋白的最佳诱导温度是30℃,异丙基-β-D-硫代吡喃半乳糖苷最佳诱导浓度为1.2 mmol/L。     

Semiochemicals of the common bed bug,Cimex lectularius L. (Hemiptera: Cimicidae), and their potential for use in monitoring and control

The recent resurgence of the common bed bug, Cimex lectularius L., has driven an increase in research into the biology and behaviour of this pest. Current control is reliant on the application of insecticides, but, owing to the development of insecticide resistance, there is a need for new tools and techniques. Semiochemicals (behaviour‐ and physiology‐modifying chemicals) could be exploited for management of bed bugs. The aim of this review was to evaluate studies undertaken in bed bug chemical ecology to date, with particular reference to how the research could be exploited for monitoring and control. Bed bugs, like many other insects, have a complex olfactory system. Recent studies have characterised the olfactory sensilla, located on the terminal segment of the antennae, to functional classes by electrophysiological screening. Behavioural studies have revealed the presence of an alarm pheromone and potential airborne aggregation semiochemicals, but it is not yet understood if bed bugs use a sex pheromone during mating. Host location cues have been investigated, and carbon dioxide has been found to be highly attractive both in laboratory and in field studies. Recent field trials have tested blends of other potential kairomones, which have been shown to have an additive effect when used in a heated bed bug trap with carbon dioxide. The trap, which combines heat and kairomones, is the only trap currently available with proven efficacy in the field. In order for semiochemicals to be useful for bed bug management, an increased knowledge and understanding of the biology, behaviour and chemical ecology of this insect is essential. Copyright © 2010 Society of Chemical Industry     

白菜型油菜BraSAUR基因家族鉴定及其表达分析

SAUR(Small auxin-up RNA)是生长素早期响应逆境胁迫的基因,本文研究白菜型油菜全基因组中SAUR家族的信息,分析了该家族成员的基本特征。以强抗寒性白菜型冬油菜品种陇油7号（L7）和弱抗寒性冬油菜品种陇Lenox（X）为试验材料,采用低温和干旱处理,应用荧光定量技术分析不同基因在不同品种中的表达特性,筛选差异表达基因,为研究生长素早期应答基因调控白菜型冬油菜生长点发育机理提供支撑。结果表明：白菜型油菜的BraSAUR基因共有142个,在10条染色体中不对称分布,主要分布在2、3号染色体上,基因长度较短,且大多数基因没有内含子。qRT-PCR结果表明,低温处理后,与CK相比,在两个品种的叶片中,Bra029452的表达量变化趋势不同,24 h时在L7中的表达量是X的24倍,在生长点中,Bra010501在L7中24 h时表达量达到CK的4倍,而在X中是先增加后降低的趋势。模拟干旱胁迫后,Bra029452在L7的叶片中的表达量均显著高于CK,在X中则是逐渐降低,在L7的生长点中1 h和24 h表达量均高于CK,但在X中则表现为先降低后升高。低温胁迫和干旱胁迫条件下,Bra029452基因表达量在强抗寒性油菜品种L7的叶片及生长点中均逐渐升高,可推断该基因同时参与白菜型冬油菜耐受低温、干旱的调控过程。     

DNA insecticides: the lethal potency of LdMNPV IAP-2 gene antisense oligonucleotides in pre-infected gypsy moth (Lymantria dispar L.) larvae

In this study, we designed and analysed the insecticidal effectiveness of two short single-stranded DNA fragments from LdMNPV (Lymantria dispar multicapsid nuclear polyhedrosis virus) IAP-2 gene. Our results show that the ssDNA fragments from the antisense region is selectively lethal, and rapidly decreases the population of second instar gypsy moth (Lymantria dispar L.) larvae one day post-treatment (Control-H₂O group vs oligoA_n group, χ² = 5; p < 0.05) when infected with LdMNPV as a trigger, before treatment through feeding with 75 pmol/µl of synthesized fragments from LdMNPV IAP-2 gene. Data analysis on larvae biomass did not show significant influence in all groups of the experiment when compared with the Control-H₂O group. Relatively, our preliminary evaluation of biochemical parameters (total glucose and total protein concentrations) did not show significant response to the applied ssDNA oligonucleotides. Our conclusive remarks based on mortality data support the concept that antisense oligonucleotides from LdMNPV IAP-2 gene can act as an insecticide against pre-infected gypsy moth larvae.     

低剂量杀线虫剂对马铃薯腐烂茎线虫三个热激蛋白70 mRNA表达的影响

为了解马铃薯腐烂茎线虫Ditylenchus destructor对低剂量杀线虫剂胁迫的适应机制,采用RTPCR和RACE技术克隆了3个热激蛋白70基因Dd-hsp70-A(KF792307)、Dd-hsp70-C(JQ422276)和Dd-hsp70-F(JQ422277),并利用实时荧光定量PCR分别检测了33℃热激及低剂量(10、1、0.1、0.01和0.001μg/m L)杀线虫剂阿维菌素、丙溴磷和涕灭威处理对3个Dd-hsp70基因mRNA表达量的影响。结果表明,3个Dd-hsp70基因在翻译区均含有内含子,编码的氨基酸序列均包含了完整的保守结构域和3段保守的HSP70家族签名序列,且在氨基酸C末端具有保守的亚细胞定位基序。33℃热激3、6 h及0.1μg/m L涕灭威浸渍处理24 h,马铃薯腐烂茎线虫Dd-hsp70-A基因mRNA表达量分别比对照显著上调1.865、4.127和1.634倍;其它处理的mRNA表达量与对照差异均不显著。证实了Dd-hsp70-A、Dd-hsp70-C和Dd-hsp70-F基因均为组成型,其中Dd-hsp70-A基因的响应在植物线虫应对低剂量杀线虫剂胁迫过程中具有重要作用。     

白菜型冬油菜NCED3基因、启动子的克隆及其表达分析

从2个不同抗寒性的冬油菜品种中克隆了NCED3基因及其启动子序列,并分析其在叶片和根中的表达,研究NCED3基因在冬油菜中的作用机理。结果表明,陇油6号的NCED3基因开放阅读框(ORF)长度为1 794 bp,编码597个氨基酸,分子量65.74 kD,理论等电点为5.81;天油2号的ORF与其长度相同,分子量为65.78 kD,理论等电点为5.94。2个蛋白都是亲水蛋白,具有疏水峰。根据预测,启动子具有生物过程中常见的顺式作用元件如CAAT-box等、分生组织表达CAT-box相关的顺式作用元件、-30 TATA box附近的核心启动子元件等,还有ABRE、TGA-element、CGTCA-motif、TGACG-element等激素响应元件,此外,还鉴定出低温响应元件（LTR）。2个品种启动子序列的相似度为99.38%,只有1个不同的顺式作用元件,即circadian,推测其与昼夜节律相关。低温、PEG及ABA处理后NCED3在叶片和根中的表达均高于对照,增加范围为0.07~6.48,且均于8 h达到峰值。与根系的表达特性相比,胁迫处理后叶片的基因表达均在2 h显著升高,天油2号的升高幅度（1.54~6.00）均大于陇油6号（0.04~1.95）。     

莲草直胸跳甲热激蛋白90基因的分子特征、表达模式及对温度胁迫的响应

莲草直胸跳甲Agasicles hygrophila是世界性入侵杂草空心莲子草Alternanthera philoxeroides的专食性天敌,冬季低温和夏季高温会影响其种群数量从而降低防控效果。为进一步探讨莲草直胸跳甲对温度胁迫适应性的分子生态机制,本研究对其热激蛋白90(AhHSP90)进行了蛋白结构、磷酸化修饰及系统发育等生物信息学分析,并采用荧光定量PCR检测了AhHSP90基因的时空表达动态及不同温度胁迫后的表达。RT-qPCR结果显示,AhHSP90在莲草直胸跳甲整个生活史及雌成虫各组织中均有表达;高温(30、35和40℃)、低温(-5、0、5、10、15和20℃)胁迫2 h后,AhHSP90在高温40℃下表达显著升高,但在其他温度下无显著差异。根据对AhHSP90分子特征、表达模式以及对温度胁迫的响应等方面的综合分析,推测其可能在莲草直胸跳甲发育及抵抗高温过程中发挥着重要的作用。     

Chloris polydactyla (L.) Sw., a perennial Poaceae weed: Emergence, seed production, and its management in Brazil

Experiments were conducted to evaluate the plant emergence and seed production of Chloris polydactyla and the efficacy of herbicides for its control. The plants emerged mainly when the seeds were placed on the soil surface at ≤ 3 cm depth. Isolated plants produced a great amount of seeds. The pre-emergence herbicides, acetochlor, atrazine + simazine, s-metolachlor, alachlor, and trifluralin, were effective for C. polydactyla control. The postemergence herbicides, clodinafop-propargil, haloxyfop-methyl, clethodim, fluazifop- p -butil, tepraloxydim, sethoxydim, and quizalofop- p -tefuril showed satisfactory control of the plants at a 20 cm height with six leaves. During the flowering stage (85 cm plant height), only glyphosate was effective in controlling C. polydactyla .     

沙葱萤叶甲热激蛋白基因GdHsp10a的克隆、分子特征与表达分析

为明确热激蛋白HSP10在沙葱萤叶甲Galeruca daurica生长发育过程中的作用,采用RTPCR及RACE技术克隆沙葱萤叶甲Hsp10基因cDNA的全长序列,采用生物信息学方法分析其序列特征,并利用qPCR技术对该基因在沙葱萤叶甲不同发育阶段、成虫羽化后不同时期以及不同温度下的表达谱进行分析。结果表明,克隆获得1条新的沙葱萤叶甲Hsp10基因,命名为GdHsp10a,GenBank登录号为MG460308,cDNA序列全长为526 bp,开放阅读框为333 bp,编码蛋白含110个氨基酸,预测分子量为11.97 kD,等电点为9.74;无信号肽及跨膜结构。同源比对及系统进化分析表明,GdHSP10a与光肩星天牛Anoplophora glabripennis HSP10亲缘关系最近,氨基酸序列一致性为53.15%。qPCR结果表明,GdHsp10a在沙葱萤叶甲各发育阶段均有表达,其中在卵期和成虫期的表达量显著高于幼虫期、预蛹期及蛹期;成虫羽化后不同时期表达量差异显著,25 d时表达量最高,其次为100、10和7 d时的表达量;温度对GdHsp10a表达量有显著影响,30℃下表达量最高,35℃下表达量次之,15、20、25及40℃下表达量最低且无显著差异。表明GdHsp10a可能在沙葱萤叶甲生长发育及成虫越夏中起着多重作用。