Cloning and Sequencing of a Gene Encoding GOBP2 in the Antenna of Spodoptera exigua

A pair of degenerate primers was designed, based on the comparison of five insects‘ GOBP2 gene sequences reported previously. A specific band (about 400bp in length) was amplified from cDNA of Spodoptera exigua antenna and another specific band (about 2kb in length) was amplified from genomic DNA.The two segments were cloned into T-easy vector, respectively. Results of sequencing and structural analysis showed that the full-length of GOBP2Sexi ORF is 426bp, 141 amino acid residues were encoded. The predicted MW and pI are 16.07ku and 5.09, respectively. There are six conservative Cys locus in the sequence, which is the typical characteristic of OBPs. GOBP2Sexi gene was inserted by two introns between amino acid residue 22 and 23 and between 82 and 83. The length of two introns is 160bp and 1403bp. Results of Northern blot showed that GOBP2 gene expressed specifically in the antenna of Spodoptera exigua, and the expression level is nearly equal in the antenna of male and female moths. The sequence was deposited in GenBank/EMBL and the accession number is AJ294809.     

Sub-Lethal Effects of Fenvalerate on the Development,Fecundity, and Juvenile Hormone Esterase Activity of Diamondback Moth,Plutella xylostella （L.）

The toxicities of fenvalerate （20% EC） to the 3rd instar larvae of diamondback moth （DBM）, Plutella xylostella （L.）, reared on three host plants viz., radish, oilseed rape, and cabbage were tested. The LC50 values of fenvalerate to the 3rd instar larvae of DBM varied with host plants, however, there wasn＇t any significant difference among them （P〉 0.05）. Similarly, DBM fed on three host plants had same pupal weight, pupal period, pupation rate, adult emergence rate, female ratio, and fecundity. The activity of juvenile hormone esterase （JHE, EC 3.1.1.1） in the 3rd instar larvae of DMB did not significantly vary with host plants, either. These suggested that DBM had similar fitness on the three host plant species. When fed on the host plants pretreated with fenvalerate at the concentrations equivalent to LC20, LC50 and LC50, the pupation rate, pupal weight, adult emergence rate, female ratio, fecundity, and JHE activity of the tested insects were declined as compared with insects in control treatments fed on the same host plant species. Furthermore, the pupal period of the tested insects was extended after fenvalerate treatment. The decrease in JHE activity after fenvalerate treatment in the tested insects could partly explain the changes in the mentioned growth parameters. Whether the role of fenvalerate in the inhibition of JHE activity could serve as a new way to control DBM needs further investigation.     

Analysis of sex pheromone production and field trapping of the Asian corn borer(Ostrinia furnacalis Guenée) in Xinjiang,China

Identifying the sex pheromone systems of local pest populations facilitates their management, especially for moth species that show significant geographic variation in sex pheromone communication. We investigated the pheromone production and behavioral responses of the Asian corn borer(Ostrinia furnacalis Guenée; ACB) in Xinjiang, China. The ACB produces three compounds:(Z)-12-tetradecenyl acetate(Z12-14:Ac) and(E)-12-tetradecenyl acetate(E12-14:Ac)which are two sex pheromone compounds, and n-te...     

Sub-Lethal Effects of Fenvalerate on the Development,Fecundity, and Juvenile Hormone Esterase Activity of Diamondback Moth,Plutella xylostella (L.)

The toxicities of fenvalerate (20% EC) to the 3rd instar larvae of diamondback moth (DBM), Plutella xylostella (L.), reared on three host plants viz., radish, oilseed rape, and cabbage were tested. The LC50 values of fenvalerate to the 3rd instar larvae of DBM varied with host plants, however, there wasn’t any significant difference among them (P 0.05). Similarly, DBM fed on three host plants had same pupal weight, pupal period, pupation rate, adult emergence rate, female ratio, and fecundity. The activity of juvenile hormone esterase (JHE, EC 3.1.1.1) in the 3rd instar larvae of DMB did not significantly vary with host plants, either. These suggested that DBM had similar fitness on the three host plant species. When fed on the host plants pretreated with fenvalerate at the concentrations equivalent to LC20, LC50 and LC80, the pupation rate, pupal weight, adult emergence rate, female ratio, fecundity, and JHE activity of the tested insects were declined as compared with insects in control treatments fed on the same host plant species. Furthermore, the pupal period of the tested insects was extended after fenvalerate treatment. The decrease in JHE activity after fenvalerate treatment in the tested insects could partly explain the changes in the mentioned growth parameters. Whether the role of fenvalerate in the inhibition of JHE activity could serve as a new way to control DBM needs further investigation.     

Optimization of the sex pheromone-based method for trapping field populations of Phthorimaea operculella(Zeller) in South China

Despite the identification of the potato tuber moth Phthorimaea operculella(Zeller) sex pheromone, no effective application based on this pheromone has yet been developed and evaluated. This study investigated the effect of pheromone lures, trap densities, heights of trap deployment, and pheromone doses in Yunnan, China, for the purpose of increasing the control efficiency of P. operculella and improving the application of pheromone technology in the field. The results showed that lures made of corn oil and red PVC pipes attracted the highest number of moths(11.73±1.90 per trap per day). Sex pheromone loading of 100 μg was optimal for trapping moths, but higher doses of pheromone inhibited attraction. The density of traps did not affect capture rates; therefore, the optimum trap density was 30–40 traps ha~(–1). The optimum height of trap deployment was not above the height of the plant canopy. This study provides technical details necessary for the monitoring and control of potato tuber moth using sex pheromones.     

高大冷杉温室Strophosoma象甲的微生物防治

In Denmark, the weevils Strophosoma melanogrammum and S.capitatum cause economic damage in Noble fir due to the adult stage feeding on the needles.No chemical treatments of these weevils are allowed in Denmark,so biological control is an attractive solution.We evaluated the potential for microbial control of larvae of Strophosoma spp.based on laboratory bioassays and field applications,taking effect on both target and non-target into consideration,as well as persistence of the applied fungus.In the laboratory Beauveria bassiana,Paecilomyces farinosus and Metarhizium anisopliae were able to infect and cause mycosis in Strophosoma larvae.Among the tested isolates the most virulent isolate was M.anisopliae BIPESCO 5,which resulted in 80 % mortality.In the field experiment M.anisopliae,isolate BIPESCO 5,was applied to the soil as a conidial suspension against larvae of Strophosoma spp.The effect of the fungus on the target population was monitored at a weekly basis by counts of emerging adult weevils during their activity periods.The population of Strophosoma spp.was reduced by up to 60% in treated plots compared to control plots.The non-target effects of M.anisopliae were studied by sampling insects and ticks from both treated and control plots.Seven days after treatment,two sampled insect orders (Hemiptera and Coleoptera) and ticks were found with prevalences of M.anisopliae above 50%,compared to no infection in the insects collected from control plots.Infections in coccinellids were found as long as 277 days after treatment.However,the effect on population level of non-target is still unexplored.The persistence of the fungus was documented by plating a soil suspension onto agar.We documented that conidia of M.anisopliae could persist in the greenery plantation for at least 418 days after application.     

Response of Cytochrome P450 Expression to Maize Volatiles in Helicoverpa armigera (Hner)

The 7-ethoxycoumarin O-deethylase (ECOD) activities of cytochrome P450s and differential expression of six cytochrome P450 genes induced by the volatiles from both damaged and undamaged maize plants were investigated in the cotton bollworm, Helicoverpa armigera (Hner). The ECOD activity changed with time of exposure to maize volatiles. At 36 h after cotton bollworm larvae exposure to maize volatiles, the ECOD activities in cotton bollworm damaged and artificially damaged groups were 2.36 and 4.53 times higher than the control group respectively. The relative expression levels of CYP4S1, CYP6B2 and CYP6B7 in the cotton bollworm were significantly increased in artificially damaged plant group, which was 2.93, 5.09 and 10.66 times higher than that in the control group, respectively. The expression levels of CYP6B2, CYP6B6, CYP9A12, and CYP9A14 were much lower in the larvae exposure to volatiles from both healthy and pest damaged maize seedlings than in the control group at 12 h after larvae exposure to maize volatiles. For the cotton bollworm damaged maize group, the expression of CYP4S1 and CYP9A14 increased.     

Electrophysiological responses of the rice striped stem borer Chilo suppressalis to volatiles of the trap plant vetiver grass(Vetiveria zizanioides L.)

Vetiver grass(Vetiveria zizanioides L.)was previously found to effectively attract female adults of Chilo suppressalis(Walker),an important pest of rice.To determine the volatile compounds involved in this attraction,electroantennography(EAG)responses to seven synthetic volatiles released from vetiver plants were examined.Our results indicated that the responses of C.suppressalis adult antennae to the different compounds varied widely.The compounds elicited strong EAG responses in female antennae were subsequently selected for further EAG response tests,namely,caryophyllene,β-ocimene,linalool andα-pinene.EAG responses to a combination of these four compounds did not differ significantly from the individual compounds.However,pair combination tests indicated that 0.01μgμL~(–1) linalool and 50μgμL~(–1)α-pinene,50μgμL~(–1) caryophyllene and 0.01μgμL~(–1) linalool,0.01μgμL~(–1)β-ocimene and 0.01μgμL~(–1) linalool,and 0.01μgμL~(–1)β-ocimene and 50μgμL~(–1) caryophyllene elicited significantly greater EAG responses in 3-day female moths compared to the 1-day female.These compound combinations and the corresponding ratios are probably playing an important role in attracting female adults of C.suppressalis to the vetiver grass.     

茶尺蠖信息素结合蛋白PBP2的基因克隆、原核表达及其结合功能

【目的】茶尺蠖(Ectropis obliqua)是中国茶区主要的鳞翅目害虫,其幼虫暴食性常给茶园带来巨大损失。鳞翅目昆虫雌雄个体间普遍存在着性信息素通讯环节,而茶尺蠖性信息素识别途径一直鲜有报道。论文旨在通过对茶尺蠖性信息素识别过程中的结合蛋白基因进行鉴定和功能研究,为茶尺蠖性信息素化学通讯和嗅觉信息识别传递机制提供理论依据。【方法】利用RT-PCR技术对从雄虫触角转录组数据中首次鉴定和发现的一个茶尺蠖信息素结合蛋白基因(pheromone-binding protein,PBP)2(EoblPBP2)进行全长cDNA序列克隆(Gen Bank登录号为KX421383)后,将该基因与pET32a载体连接构建表达载体。随后向导入pET32a/EoblPBP2表达质粒的大肠杆菌BL21(DE3)中对其表达载体加入终浓度1 mmol·L~(-1)的IPTG进行蛋白的诱导表达,进一步利用镍NTA琼脂糖凝胶柱和含有咪唑的上清缓冲液分离目的蛋白,以PBS缓冲液作为透析液纯化得到高浓度重组蛋白。最后通过荧光竞争法,利用N-苯基-1-萘胺(N-phenyl-1-naphthylamine,1-NPN)作为荧光报告子以放大荧光信号,随后向重组蛋白与1-NPN混合体系中分别加入(Z,Z,Z)-3,6,9-十八碳三烯以及10种测试气味后经过分子荧光光度计扫描得到相对荧光值,计算各配基的解离常数KD,研究重组蛋白与茶尺蠖性信息素和茶树挥发物的生理功能。【结果】EoblPBP2全长为492 bp,编码了163个氨基酸,蛋白相对分子质量为15.9kD,等电点为4.983,具有保守的6个半胱氨酸,根据分子进化树分析其应归属于昆虫PBPs家族。结合功能结果显示,10种测试气味均能将1-NPN与茶尺蠖EoblPBP2重组蛋白的混合体系于420 nm处的相对荧光值降至50%以下。其中β-紫罗兰酮、邻苯二甲酸二丁酯、苯乙醛、癸醛和反-2-癸烯醛等5种茶树挥发物质与EoblPBP2重组蛋白的结合能力较强,解离常数KD分别为7.923、14.830、30.368、28.068和27.597μmol·L~(-1)。而性信息素成分之一的(Z,Z,Z)-3,6,9-十八碳三烯与EoblPBP2的解离常数KD仅为172.591μmol·L~(-1),仅小于苯甲醇的解离常数KD 230.880μmol·L~(-1),而远远大于上述5种气味物质。表明EoblPBP2重组蛋白具有茶尺蠖性信息素成分((Z,Z,Z)-3,6,9-十八碳三烯)和植物挥发物质广谱结合能力,而其与性信息素的亲和力弱于大部分测试植物挥发物。【结论】EoblPBP2能与包括性信息素成分在内的多种植物挥发物结合,可能是一种具备特殊复合功能的信息素结合蛋白,可用之进一步研究茶尺蠖的性信息素识别和传递途径。     

襄阳地区甜菜夜蛾发生动态与气象因子关系研究

采用性诱法、灯诱法及田间调查法对2009~2010年襄阳地区甜菜夜蛾(Spodoptera exigua)成虫、幼虫开展动态监测。结果表明,襄阳地区甜菜夜蛾成虫主高峰出现在8~10月、幼虫高峰期出现在8~9月。选用同时期逐日气象数据,探讨襄阳地区甜菜夜蛾越冬及成虫高峰日前期气象条件。甜菜夜蛾在襄阳越冬虫源存活率低,高温少雨日照多有利于甜菜夜蛾成虫暴发。     

小菜蛾成虫对性信息素与寄主挥发性物质的触角电位反应

采用电生理方法测定小菜蛾雌、雄成虫对雌蛾性信息素（8expheromone,SP）两种主要组分顺-11-十六碳烯醛（Z11-16：Aid）和顺-11-十六碳烯乙酸酯（Z11-16：Ac）,以及性信息索与寄主植物5种挥发性物质混合物的触角电位反应．结果表明：当供试浓度为20.0g·L^-1时,雄蛾对Z11-16：Aid的EAG反应相对值显著高于Z11-16：Ac．将Z11-16：Aid和Z11-16：Ae按照质量比5：5和7：3进行混配,当供试浓度为20.0g·L^-1时,雄蛾对5：5配比的EAG反应相对值显著高于7：3配比．部分供试植物挥发性物质能增强小菜蛾对性信息素的EAG反应,但会因植物挥发性物质种类和小菜蛾性别而存在差异．雄蛾对反-2-己烯醛与SP混合物以及正己醛与SP混合物的EAG反应相对值显著高于其它供试混合物,其中对反-2-烯醛与SP混合物的EAG反应相对值显著高于雌蛾,而雌蛾对顺-3-己烯醇与SP混合物、异硫氰酸丙烯酯与SP混合物以及正己醛与SP混合物的EAG反应相对值显著高于其它供试混合物,其中对青叶醇与SP混合物、异硫氰酸丙烯酯与SP混合物的EAG反应相对值要显著高于雄蛾．因此,小菜蛾性信息素主要成分与植物挥发性物质合理混配可以降低性诱剂成本,提高诱蛾效率,特别是具有提高雌蛾引诱比例的潜能．     

小菜蛾性信息素与性信息素结合蛋白、受体蛋白结合机理研究

【目的】研究小菜蛾性信息素与性信息素结合蛋白、受体蛋白之间作用的关键氨基酸残基和作用力类型,揭示小菜蛾识别性信息素的分子机制,为开发新型性诱剂和小菜蛾的无害化防治提供新思路。【方法】运用Discovery Studio 2.5对小菜蛾性信息素结合蛋白PxylPBP2和受体蛋白PxylOR4进行同源建模,运用程序包中LibDock模块进行分子对接,运用Calculate Energy模块计算复合物结合自由能,分析性信息素Z9-14∶AC与PxylPBP2和PxylOR4的结合模式及相互作用力。【结果】Thr9是PxylPBP2与Z9-14∶AC形成氢键的关键氨基酸残基,Z9-14∶AC易与PxylOR4中的Leu残基产生疏水作用力;PxylPBP2与Z9-14∶AC结合的主要驱动力是静电力,PxylOR4与Z9-14∶AC结合的主要驱动力是范德华力,溶剂化能均抑制Z9-14∶AC与PxylPBP2和Z9-14∶AC与PxylOR4的结合。【结论】小菜蛾性信息素受体蛋白和性信息素结合蛋白在识别和结合性信息素分子方面存在明显差异,性信息素受体蛋白与性信息素反应更灵敏、形成的复合物更稳定。     

Chemical mimicry: bolas spiders emit components of moth prey species sex pheromones

Field studies have indicated that bolas spiders attract male moth prey, apparently by mimicking the odor of female moth sex pheromones. Three moth sex pheromone compounds, (Z)-9-tetradecenyl acetate, (Z)-9-tetradecenal, and (Z)-11-hexadecenal, were identified in volatile substances emitted by hunting adult female Mastophora cornigera spiders. These compounds are components of pheromone blends that attract some of this spider's moth prey species.     

中华蜜蜂气味结合蛋白AcerOBP7的表达及结合特性

[目的]中华蜜蜂(Apis cerana cerana,简称中蜂)是我国本土蜂种,也是重要的传粉昆虫和经济昆虫.气味结合蛋白(odorant binding protein,OBP)是蜜蜂嗅觉感知中的关键蛋白.在前人对中蜂AcerOBP7基因序列特征分析的基础上,本研究进一步对其表达特性及与气味物质的结合能力进行探究,...     

2个甜菜夜蛾信息素结合蛋白cDNA片段的克隆和序列分析

 通过比较几种已发表夜蛾科昆虫的信息素结合蛋白（PBP）氨基酸序列，设计合成一对简并性引物, 利用反转录多聚酶链式反应（RT-PCR）技术从甜菜夜蛾(Spodoptera exigua Hübner)雄虫触角扩增得到2个分别为275 bp和281 bp的cDNA片段SexigPBP1和SexigPBP2，其分别由92个氨基酸残基和94个氨基酸残基组成。通过在GenBank中进行序列的同源性比较，表明这2个序列与已知几种昆虫的PBP氨基酸序列具较高同源性。     

Characterization of the chemosensory protein EforCSP3 and its potential involvement in host location by Encarsia formosa

Chemosensory proteins (CSPs) perform several functions in insects. This study performed the gene expression, ligand-binding, and molecular docking assays on the EforCSP3 identified in the parasitoid wasp Encarsia formosa, to determine whether EforCSP3 functions in olfaction, especially in host location and host preference. The results showed that EforCSP3 was highly expressed in the female head, and its relative expression was much higher in adults than in other developmental stages. The fluorescence binding assays suggested that the EforCSP3 exhibited high binding affinities to a wide range of host-related volatiles, among which dibutyl phthalate, 1-octene, β-elemene, and tridecane had the strongest binding affinity with EforCSP3, besides α-humulene and β-myrcene, and should be assessed as potential attractants. Protein structure modeling and molecular docking predicted the amino acid residues of EforCSP3 possibly involved in volatile binding. α-Humulene and β-myrcene attracted E. formosa in a previous study and exhibited strong binding affinities with EforCSP3 in the current study. In conclusion, EforCSP3 may be involved in semiochemical reception by E. formosa.