枸杞红瘿蚊雌虫对三种枸杞的产卵选择性研究

【目的】枸杞红瘿蚊Gephyraulus lycantha Jiao&Kolesik是枸杞上的一种重要害虫。为探讨其对枸杞属3种寄主植物的产卵选择差异,解析影响其寄主选择的信息化学物质。【方法】采用选择和非选择性测定方法,观察枸杞红瘿蚊在宁夏枸杞、中华枸杞和黑果枸杞花蕾上的产卵选择性;通过Y型嗅觉仪,测定孕卵雌虫对这3种枸杞挥发物的行为选择偏好;运用动态顶空吸附法和气相色谱-质谱联用技术,分析影响枸杞红瘿蚊产卵选择的3种枸杞挥发物的成分差异。【结果】宁夏枸杞为枸杞红瘿蚊最嗜好的寄主植物,孕卵雌虫对其幼嫩花蕾的产卵选择率和花蕾中的落卵量显著高于中华枸杞和黑果枸杞(P<0.05)。无论是与空白对照相比,还是3种枸杞挥发物相互比较,枸杞红瘿蚊孕卵雌虫对宁夏枸杞挥发物均具有显著的嗅觉选择偏好(P<0.05)。3种枸杞挥发物的种类和释放量存在一定差异,宁夏枸杞与中华枸杞挥发物的组分较为相似,均含有较高比例的酯类物质,而酚类化合物是中华枸杞的特有种类;黑果枸杞中的酯类物质含量很低,但酮类物质的含量极高。【结论】3种寄主植物中宁夏枸杞是枸杞红瘿蚊最嗜好的寄主植物,不同枸杞花蕾挥发...     

枸杞红瘿蚊对寄主植物挥发物的电生理和行为反应

植物挥发物是植食性昆虫定位寄主的重要信息物质。枸杞红瘿蚊是宁夏枸杞的主要成灾害虫,野外发现其雌虫对枸杞幼嫩花蕾具有更强的产卵趋性。为明确枸杞红瘿蚊对枸杞不同阶段花蕾挥发物的选择差异性,解析吸引其选择产卵的关键信息化学物质,采用顶空固相微萃取法和气相色谱-质谱联用技术(GC-MS),系统研究枸杞幼嫩花蕾和成熟花蕾挥发物的成分差异,选择幼嫩花蕾挥发物中的特有成分及其与成熟花蕾挥发物共有成分共8种作为候选挥发物;通过气相色谱-触角电位联用仪(GC-EAD)和Y型嗅觉仪,测定枸杞红瘿蚊对上述挥发物的电生理和行为反应,筛选关键活性挥发物。结果显示: 枸杞幼嫩花蕾和成熟花蕾挥发物的种类和释放量存在明显差异;8种化合物能激发枸杞红瘿蚊产生持续触角电生理反应,其中,有5种[3-蒈烯、莰烯、萜品油烯、d-柠檬烯和(+)-α-蒎烯]能刺激枸杞红瘿蚊产生显著趋向或躲避行为。利用枸杞挥发物设计枸杞红瘿蚊引诱剂或忌避剂,可为田间安全防控红瘿蚊提供新的途径。     

桑天牛卵长尾啮小蜂的寄主选择定位行为

本文对桑天牛卵长尾啮小蜂Aprostocetus prolixus LaSalle et Huang的寄主选择定位行为进行了系统研究。已有研究表明,寄主植物-寄主昆虫复合体释放的挥发物对寄生蜂有显著的引诱作用。为了查明寄主植物 寄主昆虫复合体中挥发性引诱物质的来源,对不同处理桑枝（正常桑枝、机械损伤桑枝、系统枝、桑天牛Apriona germari（Hope）咬食和产卵桑枝）、桑天牛虫粪及雌雄两性桑天牛所释放的挥发物分别进行了测定。结果显示：不同处理桑枝对寄生蜂都具有显著的引诱作用,而且产卵桑枝的引诱活性最大;桑天牛虫粪的气味对寄生蜂有引诱活性,而雌、雄桑天牛体表挥发物对寄生蜂的引诱效果不明显。桑天牛爬行痕迹对寄生蜂的微栖境接受行为没有影响,而桑天牛虫粪中的信息物质在寄生蜂的微栖境接受过程中起着重要作用。寄生蜂对产卵桑枝段的选择几率明显高于正常桑枝段和咬食桑枝段,而对不同植物上产卵刻槽的选择没有差异; 刻槽表面存在着与此卵寄生蜂寄主识别相关的信息物质。     

桉树枝瘿姬小蜂虫瘿解剖特征与寄主叶片生理指标的变化

采用人工接蜂、桉树组织石蜡切片和生化组分测定等方法研究了桉树受桉树枝瘿姬小蜂诱导后的生理生化响应机制.结果表明:DH201-2叶柄角质层厚度和油囊数量均较GL-UG9的厚、多,且差异均达到极显著水平(P角质层厚度=0.00001 ＜0.01,P油囊数量=0.00209＜0.01),但是GL-UG9叶柄表皮细胞厚度和维管束数量均较DH201-2厚、多,差异分别达到显著水平(P=0.015215＜0.05)和极显著水平(P=0.002375＜0.01),DH201-2茎皮层薄壁细胞厚度、油囊直径、维管束数量较GL-UG9厚、多,差异分别为显著(P皮层薄壁细胞厚度=0.04071 ＜0.05)、极显著(P油囊直径=000016＜0.05)、极显著(P维管束数量=0.00000＜0.01).而GLUG9茎角质层和表皮细胞厚度均较DH201-2厚,差异达到了极显著水平(P角质层厚度=0.00167,P表皮细胞厚度=0.00000＜0.01);桉树枝瘿姬小蜂虫瘿为组织瘿,由内到外可以分为:营养组织层、薄/厚壁组织层、维管束层、皮层、表皮等结构;接种桉树枝瘿姬小蜂成虫后,桉树叶片可溶性总糖、游离氨基酸、叶绿素含量均升高,差异达到了极显著水平(P＜0.01),但是蛋白质、pH值、类黄酮、总酚的变化没有达到显著水平(P＞0.05);吲哚乙酸氧化酶、过氧化物、过氧化氢酶活力均有不同程度的升高.研究显示桉树枝瘿姬小蜂入侵诱导了桉树一系列的生理生化变化,实验结果为抗桉树枝瘿姬小蜂桉树无性系的选育技术体系构建提供了理论基础.     

不同番茄品种挥发物对B型烟粉虱寄主选择行为的影响

采用顶空固相微萃取和气相色谱-质谱法鉴定了6个番茄品种(浙杂809、浙杂203、合作903、凯特一号、黄椭圆和金妃)植株挥发物的成分,并利用Y型嗅觉仪测定了烟粉虱对不同番茄品种植株及其挥发物的嗅觉反应.结果表明:从6个番茄品种中共鉴定出13种化合物,其主要成分为萜类化合物,品种间挥发物的组成成分和各成分所占比例存在差异.(+)-3-蒈烯和β-石竹烯对B型烟粉虱的驱避性较其他萜类强.烟粉虱对含萜类挥发物种类多、比例高的品种(如浙杂809和浙杂203)选择性较弱,而对含萜类挥发物种类少、比例低的品种(如黄椭圆和金妃)选择性较强.     

2种不同寄主对桉树枝瘿姬小蜂体内细菌多样性的影响

[目的]桉树枝瘿姬小蜂是一种林业的重要入侵害虫,为了探明桉树枝瘿姬小蜂的寄主适应机制,研究2种不同寄主植物对桉树枝瘿姬小蜂体内细菌群落组成及多样性的影响.[方法]以分别取食巨园桉DH 201-2和窿缘桉的桉树枝瘿姬小蜂雌性成虫为材料,采用Illumina HiSeq高通量测序技术对桉树枝瘿姬小蜂体内细菌16S rDNA...     

烟粉虱生物型对浅黄恩蚜小蜂寄主选择及个体发育的影响

为探讨寄生蜂在Q型烟粉虱Bemisia tabaci替代B型烟粉虱的过程中是否起作用, 我们在实验室条件(温度27±1℃, 光周期16L∶8D, 相对湿度RH 70%～80%)下, 观察了浅黄恩蚜小蜂Encarsia sophia寄生B型和Q型烟粉虱若虫的行为, 研究了浅黄恩蚜小蜂对B型和Q型烟粉虱若虫的选择性、 烟粉虱生物型对浅黄恩蚜小蜂取食数量及个体发育的影响。结果发现, 浅黄恩蚜小蜂体外检测时间在B型和Q型烟粉虱若虫间差异不显著, 而寄生Q型烟粉虱若虫时的体内检测和产卵时间(190.2±14.6 s）显著高于寄生B型时所用时间(140.0±7.5 s)。在非选择条件下, 浅黄恩蚜小蜂寄生B型烟粉虱若虫的数量(8.1±0.5头)及总产卵量（9.3±0.6粒）显著高于仅提供Q型烟粉虱的寄生数量(6.3±0.5头)及总产卵量(7.0±0.6粒); 而被寄生若虫单头着卵量在处理间差异不显著。在选择性条件下, 该蜂寄生B型烟粉虱若虫量(3.1±0.4头)、总产卵量(3.8±0.5粒)及被寄生若虫单头着卵量(1.2±0.1粒)都显著高于寄生Q型烟粉虱时的情况(1.8±0.3头、1.8±0.4粒、0.7±0.1粒)。被寄生蜂取食的B型与Q型烟粉虱数量间差异不显著, 但对于同一生物型而言, 交配过的雌蜂能够取食更多的烟粉虱若虫。以B型烟粉虱为寄主时, 浅黄恩蚜小蜂雌蜂卵-黑蛹(7.2±0.1 d)、黑蛹-羽化(5.2±0.1 d)的发育时间与以Q型烟粉虱若虫为寄主时的相应发育时间(7.3±0.1 d, 5.6±0.1 d)间无显著性差异。以B型烟粉虱为寄主时寄生蜂的羽化率（73.55%±1.42%）与以Q型烟粉虱为寄主时的羽化率（68.42%±13.01%）间差异不显著。这些结果表明, 虽然浅黄恩蚜小蜂发育时间、 羽化率在烟粉虱2种生物型间无显著差异, 但该小蜂倾向于B型烟粉虱若虫作为寄主, 而且, 以B型烟粉虱若虫为寄主时, 小蜂的产卵量和寄生若虫数量均增加。但田间浅黄恩蚜小蜂的存在是否有助于Q型烟粉虱成为B型和Q型混合种群的优势种群, 还需进一步研究。     

7种松树挥发物分析及其主要萜烯类物质对红脂大小蠹行为选择的影响

入侵种红脂大小蠹在我国逐渐向北扩散至内蒙古和辽宁等地.同时在林间发现,相对于油松Pinus tabuliformis,其更偏好危害樟子松Pinus sylvestris var.mongolica.本文主要分析我国7种松树挥发性物质以及新发生地红脂大小蠹对其中主要物质的行为选择.本研究采用动态顶空采样法和气相色谱——质...     

板栗挥发物对桃蛀螟成虫寄主选择行为的影响

通过田间调查及行为反应、EAG反应和产卵选择性测定,研究了板栗挥发物对桃蛀螟（Conogethes punctiferalis）成虫寄主选择行为的影响.2004-2008年的田间调查结果表明：桃蛀螟在农大1号板栗上的蛀果率为16.1%～25.3%,而在河源油栗上的蛀果率均小于5%,桃蛀螟对前者的危害明显较重.农大1号板栗的果实和叶片挥发物对桃蛀螟雌蛾均有显著吸引作用,其中果实比叶片挥发物的吸引作用更强,但上述挥发物对雄蛾没有明显吸引作用;河源油栗的果实和叶片挥发物则对雌、雄蛾均无吸引作用.触角电位反应试验表明,桃蛀螟雌蛾对农大1号板栗果实挥发物的反应比河源油栗果实强烈,但雄蛾没有明显差异;同一品种中,雌、雄蛾对果实的反应均比叶片强烈.桃蛀螟雌蛾在农大1号板栗果实上的产卵量明显高于叶片及河源油栗的果实和叶片,而后三者之间差异不显著.     

Herbivore-induced plant volatiles mediate host selection by a root herbivore

In response to herbivore attack, plants mobilize chemical defenses and release distinct bouquets of volatiles. Aboveground herbivores are known to use changes in leaf volatile patterns to make foraging decisions, but it remains unclear whether belowground herbivores also use volatiles to select suitable host plants. We therefore investigated how above- and belowground infestation affects the performance of the root feeder Diabrotica virgifera virgifera, and whether the larvae of this specialized beetle are able to use volatile cues to assess from a distance whether a potential host plant is already under herbivore attack. Diabrotica virgifera larvae showed stronger growth on roots previously attacked by conspecific larvae, but performed more poorly on roots of plants whose leaves had been attacked by larvae of the moth Spodoptera littoralis. Fittingly, D. virgifera larvae were attracted to plants that were infested with conspecifics, whereas they avoided plants that were attacked by S. littoralis. We identified (E)-β-caryophyllene, which is induced by D. virgifera, and ethylene, which is suppressed by S. littoralis, as two signals used by D. virgifera larvae to locate plants that are most suitable for their development. Our study demonstrates that soil-dwelling insects can use herbivore-induced changes in root volatile emissions to identify suitable host plants.     

Odour masking of tomato volatiles by coriander volatiles in host plant selection of Bemisia tabaci biotype B

The silverleaf whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is one of the most important pest insects in tomato crop systems worldwide. It has been previously demonstrated that intercropping tomato [Solanum lycopersicum L. Mill. (Solanaceae)] with coriander [Coriandrum sativum L. (Apiaceae)] reduces the incidence and severity of damage caused by B. tabaci. However, it is not yet known how coriander affects the insect′s behaviour. We evaluated the attractiveness of tomato constitutive volatiles to B. tabaci and what effect coriander constitutive volatiles have on the insect′s behaviour. To this end, we conducted three bioassays in a multiple‐choice four‐arm olfactometer (‘×’ type), measuring B. tabaci behaviour when offered tomato and coriander constitutive volatiles presented alone as well as together. We also evaluated the colonisation and establishment of B. tabaci in experimental plots with only single tomato plants and tomatoes intercropped with coriander in a greenhouse. Bemisia tabaci males and females recognised tomato constitutive volatiles as a positive stimulus (kairomonal effect), indicating that semiochemicals from this plant can play an important role in the insect’s host plant selection. Coriander constitutive volatiles reduced the attractiveness of tomato volatiles but no repellency to these volatiles was observed. Greater numbers of adults and nymphs of B. tabaci per plant were observed in tomato monoculture plots than in tomato intercropped with coriander. We suggest that coriander constitutive volatiles have an odour masking effect on tomato volatiles, thus interfering in the host plant selection of B. tabaci.     

寄主挥发物、叶色和表皮毛在美洲斑潜蝇寄主选择中的作用

在室内条件下 ,初步研究了寄主挥发物、叶色和表皮毛在美洲斑潜蝇寄主选择中的作用。在嗅觉仪试验中 ,寄主叶片挥发物对美洲斑潜蝇雌成虫没有明显的引诱作用 ;在叶色反应试验中 ,美洲斑潜蝇雌成虫在叶子圆片上停留的时间明显大于在滤纸圆片上停留的时间 (p<0 .0 1) ,其在有叶片区域分布的数量明显多于空白对照 (p <0 .0 1) ;在表皮毛试验中 ,美洲斑潜蝇在无毛叶片上的产卵量明显大于在有毛叶片上的产卵量 (p <0 .0 1)。上述结果表明 ,在对寄主的定向和定位过程中 ,美洲斑潜蝇的视觉起着重要的作用 ,而嗅觉不起作用 ;叶片表皮毛有抑制产卵的作用     

Taxonomic analysis of volatiles emitted by ornamental crabapple flowers

To identify and classify volatile compounds in the fragrances of crabapple flowers from ornamental and original species in the peak April Tai’an, Shandong flowering season. Volatile components from flowers were identified using dynamic-headspace sampling, purge and trap and GC/MS. Eighty compounds were detected in the 17 ornamental crabapple cultivars, while sixty-eight compounds were found in the nine original species, including forty-four compounds in both the original species and cultivars. The main volatile components and common components of crabapple flower aroma include: 3-methyl-1-butanol, ocimene, benzyl alcohol, 3-methyl-4-oxo-pentanoic acid and heptane. Based on the relative volatile content the 26 taxa could be classified into seven different groups through UPGMA cluster analysis. The different volatile contents, such as myrcene and benzaldehyde, result in the extraordinary aroma of different crabapple varieties. M. ‘Dolgo’, M. ‘Eleyi’, M. ‘Hopa’, M. ‘Liset’, M. ‘Makamik’ and M. ‘Royalty’ are good breeding varieties of sweet flowering crabapples which could be used to breed additional ornamental cultivars with excellent fragrance and high value.     

Pine volatiles mediate host selection for oviposition by Thaumetopoea pityocampa (Lep., Notodontidae)

The oviposition behaviour and host selection by females of the pine processionary moth, Thaumetopoea pityocampa, was studied under two conditions: in a field insectary and in a pine stand. An oviposition choice test was conducted in an insectary cage, using artificial Christmas trees (ACTs) baited with extracts from four pine species: Pinus pinea, Pinus pinaster, Pinus halepensis and Pinus brutia, plus a control. Females oviposited significantly more egg batches on the ACT baited with a P. brutia extract, while no oviposition occurred on the control ACT. In a large P. pinea stand, two groups of randomly selected trees were marked and baited respectively with an extract of P. brutia, which was the preferred species under insectary conditions and with a solvent, to act as control. Results showed that oviposition in the field followed an aggregated pattern, fitting a negative binomial distribution and that trees baited with P. brutia extracts, received a significantly larger number of egg‐batches than control trees. In parallel, the volatiles emitted by all pine extracts tested where analysed by gas chromatography and mass spectrometry (GC‐MS), coupled to a time‐of‐flight (TOF) mass analyser after solid phase microextraction (SPME), resulting in the identification of 26 compounds. Comparative chromatograms showed qualitative differences among the pine species used, some compounds being present in one of them only. Findings demonstrate for the first time that: (i) T. pityocampa females discriminate among bouquets extracted from different host pine species and exhibit oviposition preferences; and (ii) olfactory cues play an important role in mediating the selection process.     

Age-dependent response of female melon fly,Zeugodacus cucurbitae (Diptera: Tephritidae), to volatiles emitted from damaged host fruits

In many insect species including fruit flies (Diptera: Tephritidae), the behavioral responses to volatiles emitted by their host plants can be modulated by environmental conditions and by the physiological state of the insect. Here, we quantified (1) the effects of female age on the attraction of female melon fly, Zeugodacus cucurbitae (Diptera: Tephritidae) to volatiles emitted by intact and mechanically damaged tomato (Solanum lycopersicum), eggplant (S. melongena), zucchini (Cucurbita pepo), bitter melon (Momordica charantia), and cucumber (Cucumis sativus) fruit, and (2) the influence of time elapsed since fruit damage on the outcome. The investigations were conducted under semi-natural conditions in Hawai’i. Results from the first experiment revealed that, for freshly damaged tomato, eggplant, and zucchini, the level of female response was comparatively low and was not affected by female age. For bitter melon and cucumber, higher levels of response to freshly damaged fruit were documented, and the response levels gradually increased as female age increased from 1 to 4 weeks, reaching 70% for 4-week-old females exposed to cucumber odor. Results from our second experiment indicated that, on average, 56% of the females released responded in 20 min when cucumbers were freshly sliced, and the level of response was reduced 6-fold within a couple of hours. Females did not respond to tomato and cucumber odor when fruits were damaged >8 h before testing. Fruit volatiles involved in female Z. cucurbitae attraction seem to be released shortly upon mechanical damage and they are short-lived. The plasticity of the olfaction-driven behavior observed in Z. cucurbitae depending on female age and on the strength of the olfactory cues associated with preferred and less preferred hosts, adds another dimension to our understanding of the host-seeking behavior of this invasive species.     

Aldehyde volatiles emitted in succession from mechanically damaged leaves of poplar cuttings

Plant aldehydes are volatiles necessary to defenses against environmental stress. To explore their emissions in response to wounding, we performed gas chromatography-mass spectrometry (GC-MS) on cuttings from poplar (Populus simonii×P. pyramidalis ‘Opera 8277’) that were mechanically damaged to mimic herbivore attack. We detected 16 aldehydes, including 11 linear saturated aldehydes, 3 linear unsaturated aldehydes, and 2 non-linear aldehydes. Emissions of these aldehydes were clearly enhanced by such treatment, and exhibited a similar pattern of change, i.e., increasing in the first 2 h, then sharply decreasing before rising again at about 12 h. Two release peaks for these aldehydes were observed. Therefore, we propose two pathways for the mediation of aldehyde emissions following damage. The first peak may represent emissions from plant storage pools, whereas the second release peak might result from greater formationde novo through an activated synthesis pathway.