苹毛丽金龟触角嗅感器超微结构

利用扫描电镜和透射电镜对苹毛丽金龟Proagopertha lucidula (Faldermann)雌雄成虫触角嗅感器超微结构特征进行研究。结果表明:嗅感器集中于触角鳃片上,分布在触角鳃片表皮内陷形成的凹腔里,有5种感器,以板状感器为主,以外还有锥状感器、腔状感器、腔锥状感器和毛状感器。板状感器根据盘体形状的不同可分为4种类型,锥状感器根据锥体形状的差异可分为2种类型,腔锥状感器根据形状分为2种类型。嗅感器表皮有微孔和孔道微管。嗅感器内神经元的数目并不一致,1～2个不等。雄虫鳃片嗅感器总数显著多于雌性,是雌虫嗅感器总数1.8倍。其中雄性锥状感器的数目是雌性2倍,雌虫腔锥状感器数量是雄虫的4倍,雄虫板状感器数量是雌虫的2倍,雌雄腔状感器的数目无显著性差异。     

红缘天牛嗅觉感受器的类型及特点

利用扫描电镜对红缘天牛Asias halodendri（Pallas）的触角、下颚须和下唇须上嗅觉感受器的类型、超微形态结构及分布等特点进行观察。结果表明,红缘天牛触角、下颚须和下唇须上的嗅觉感器共有6类14种。触角上感器共有2类9种,即毛形感器1种,锥形感器8种;触角上毛形感器和Ⅱ型锥形感器长度在雌雄间有显著性差异;Ⅲ型、Ⅶ型和Ⅷ型锥形感器为雌性触角上所特有;Ⅵ型锥形感器仅见于雄性触角;触角上的感受器总数雌性数量多于雄性,背面略多于腹面和侧面。下颚须及下唇须上嗅感器共4类5种,即栓锥形感器2种、板形感器、钟形感器和边缘凹槽形感器各1种;雌性的边缘凹槽形感器明显高于雄性;下颚须和下唇须上雄性感器总数较多,腹面数量多于背面。     

四种金龟成虫触角的板形感器和腔锥形感器形态对比

板形感器(placodea sensilla)和腔锥形感器(coeloconica sensilla)是金龟子类害虫最重要的两种嗅感器.本文运用扫描电子显微镜分别对铜绿丽金龟Anomala corpulenta Motschulsky、华北大黑鳃金龟Holotrichia oblita Fald.、棕色鳃金龟Holotrichia titanis Reitter和暗黑鳃金龟Holotrichia parallela Motschulsky的雌雄成虫触角的板形感器和腔锥形感器进行了对比观察.结果表明,四种金龟成虫触角的板形感器和腔锥形感器形态既有相似性,但也存在显著差异,表现出较高的形态多样性,如铜绿丽金龟板形感器表面特化形成龟纹、华北大黑鳃金龟的梭形腔锥形感器等.研究结果丰富了四种金龟的比较形态学理论,也为金龟子的系统分类学研究积累了资料.     

麦蛾茧蜂触角感器的扫描电镜观察

应用扫描电镜对麦蛾茧蜂BraconhebetorSay的触角感器进行观察。结果表明:麦蛾茧蜂的触角上存在6种感器,分别为毛形感器,板形感器,刺形感器,鳞状感器,锥形乳头状感器和嗅孔。其中毛形感器和板形感器是主要感器,数量较大,分布较广。雌雄蜂的触角感器差异不明显。     

亚洲玉米螟成虫触角的扫描电镜观察

对亚洲玉米螟成虫触角的外部形态结构在扫描电镜下作了观察.触角由柄节、梗节和62—67个鞭节组成,触角背面被鳞片覆盖,绝大部分触角感器位于触角的腹面和侧面.所有鞭节的表皮上都有连续的网纹结构,但在柄节和梗节的表皮上则无.在雌雄蛾的触角上都可以找到以下七种感器,即栓锥感器、腔锥感器、锥形感器(即B?hm氏鬃毛)、刺形感器、耳形惑器、鳞形感器和毛形感器.毛形感器数目最多,并根据其形状和表面细微结构分为两种类型:A型和B型.除锥形感器外,所有的感器都分布在触角鞭节的网纹区上.对此昆虫的触角两性差异进行了详细的讨论.     

斑鞘豆叶甲触角感器的超微结构

斑鞘豆叶甲是大豆苗期重要害虫,本文利用扫描电镜技术观察了斑鞘豆叶甲触角感器超微形态与分布。结果表明:斑鞘豆叶甲触角感器绝大部分着生于鞭节,在鞭亚节端部和末节凹陷区感器分布密集,类型较多。基于感器外部形态可分为8种类型:毛形感器Ⅰ型和Ⅱ型、刺形感器、锥形感器、指形感器、腔锥形感器、栓锥形感器Ⅰ型和Ⅱ型、钟形感器和B hm氏鬃毛。其中毛形感器数量最多,其次是锥形感器,钟形感器最少,仅分布于雄虫触角,还着生有大量表皮孔。雌、雄虫触角感器在形态、数量和分布上均存在差异,雄虫毛形和刺形感器显著长于雌虫,刺形感器端部膨大,两种感器的数量也明显多于雌虫;雌虫与雄虫相比末节背面也具感器密集的凹陷区,指形感器短于雄虫但数量显著多于雄虫。斑鞘豆叶甲触角感器种类丰富,分布密集,雌、雄虫感器存在明显的性二型现象,其结构和类型表现出种间分化特性。     

黄曲条跳甲触角感器的扫描电镜观察

应用扫描电镜对黄曲条跳甲Phyllotreta striolata(Fabricius)成虫的触角结构、感器的类型、数量和分布进行了观察,并对雌、雄成虫触角及感器之间的差异进行了比较。结果表明:黄曲条跳甲成虫的触角为线形,共11节,即柄节、梗节和9个鞭小节。雄虫触角的长度略长于雌虫(雄:1.48±0.03 mm;雌:1.42±0.05 mm),其中,雄虫触角鞭节第3亚节长度明显长于雌虫(雄:0.19±0.02 mm;雌:0.15±0.01 mm,t=3.77,P=0.0054),且明显膨大,其余各节长度和形态在雌雄虫间差异不显著。触角感器共9种,分别为毛板形感器、刺形感器、毛形感器1型和2型、锥形感器1型、2型和3型、槽钉形感器和耳形感器。各种感器中除耳形感器仅分布在雄性触角末节外,其他类型感器的分布在雌、雄性个体间无明显差异。雄成虫触角上各种感器数量总和明显多于雌成虫,其中,毛形感器1型、锥形感器1型和耳形感器的数量雄成虫明显多于雌成虫。比较并讨论了黄曲条跳甲触角上不同类型感器的适生意义,研究结果将有助于理解黄曲条跳甲触角感器的功能和行为机制。     

桔小实蝇本地寄生蜂长尾全裂茧蜂成虫

应用扫描电镜（SEM）对桔小实蝇本地寄生蜂长尾全裂茧蜂 Diachasmimorpha longicaudata (Ashmead) 成虫的触角感器进行观察。结果表明：长尾全裂茧蜂成虫触角由柄节、梗节和鞭节组成,鞭节共 49-52小节。在触角上共有 8种感器,分别为 Bhm鬃毛、毛形感器、刺形感器、锥形感器、板形感器、腔锥形感器、钟形感器、嗅孔。毛型感器是主要感器,数量多且分布广,其次为板形感器。除了腔锥形感器 Ⅱ外,雌雄蜂没有明显的二型现象。     

宽胫夜蛾成虫触角和下唇须感器的超微形态

触角和下唇须是昆虫头部的重要感觉器官,其上被有多种类型的感器。宽胫夜蛾Protoschinia scutosa是一种重要的农业害虫,但其触角和下唇须感器研究较少。本研究利用扫描电子显微镜观察了宽胫夜蛾的触角和下唇须感器的类型、分布和超微形态。宽胫夜蛾的雌雄触角均为丝状,雌虫触角鞭节明显短于雄虫。雌雄触角均分布有8种类型感器,分别为Bhm氏鬃毛、鳞形感器、毛形感器、刺形感器、耳形感器、锥形感器、腔锥形感器和栓锥形感器。其中,毛形感器数量最多,且雄性毛形感器的数量明显多于雌性。宽胫夜蛾的下唇须为长管状,雌雄下唇须长度无显著差异。共观察到5种类型感器,即毛形感器、钟形感器、鳞形感器、刺形感器和棒形感器。毛形感器分布在下唇须基部第1节和端部第3节的陷窝器内,钟形感器位于第1节毛形感器簇之中,鳞形感器在各节均有分布,刺形感器和棒形感器只见于第3节。并对宽胫夜蛾的触角和下唇须感器的功能进行初步的推测和讨论。为昆虫感器功能分析、分类学和行为学研究提供依据。     

西藏飞蝗触角感器的扫描电镜观察

应用扫描电镜对西藏飞蝗Locusta migratoria tibetensis Chen触角的外部形态结构及其感器进行了观察和研究.结果表明,西藏飞蝗触角上存在5种感器即毛形感器、刺形感器、腔锥形感器、锥形感器和腔形感器.通过对各种感器的形态特点进行描述,发现西藏飞蝗群居型与散居型、蝗蝻与成虫、雌性与雄性的感器在类型...     

Smoke,pheromone and kairomone olfactory receptor neurons in males and females of the pine sawyer Monochamus galloprovincialis (Olivier) (Coleoptera: Cerambycidae)

The response of antennal olfactory receptor neurons (ORNs) of Monochamus galloprovincialis to several odourants was tested using single sensillum electrophysiology. Behaviourally active pheromone, and kairomone (host and sympatric bark beetle pheromone) odours were tested alongside smoke compounds released by burnt wood that are potentially attractive to the insect. The antennae bore several types of sensilla. Two plate areas in the proximal and distal ends of each antennal segment were covered with basiconic sensilla that responded to the odour stimuli. Sensilla basiconica contained one or two cells of different spike amplitude. The 32 male and 38 female ORNs tested responded with excitations or inhibitions to the different plant odours. In general the response of male and female receptors was very similar so they were pooled to perform a cluster analysis on ORN responses. Six ORNs were clearly specialised for pheromone reception. Responses to kairomone and smoke odours were less specific than those of pheromone, but a group of 9 cells was clearly excited by smoke compounds (mainly eugenol and 4-methyl 2-methoxyphenol), a group of 8 cells was very responsive to α-pinene, β-pinene and cis-verbenol, and a group of 14 cells responded to a wider range of compounds. The rest of the cells (47%) were either non-responsive or slightly inhibited by smoke compounds. Dose–response curves were obtained for several compounds. Different compounds induced significantly different latencies and these appeared to be unrelated to their boiling point.     

Electrophysiological response patterns of 16 olfactory neurons from the trichoid sensilla to odorant from fecal volatiles in the locust, locusta migratoria manilensis

Locusts are the most serious pests of crops in greater part of the world. They locate their host plants primarily through olfactory cues, using antennal chemosensilla, which house olfactory receptor neurons (ORNs). Despite the great economical interest of these species, their olfactory neurons have been poorly investigated at the functional level. In this study, we have used single sensillum recordings (SSRs) to obtain response patterns of ORNs from the antennal trichoid sensilla to various chemicals in the oriental locust Locusta migratoria. On the basis of their spontaneous spike amplitudes, trichoid sensilla could be distinguished into two types, housing two or three ORNs, respectively. These two structural types could be further classified into seven functional subtypes. Nine different odorants that are present in the locust feces were used as stimulants during SSRs. In particular, benzaldehyde elicited inhibitory responses in most of the ORNs tested. Moreover, in a majority of these ORNs, the excitatory responses obtained with trans-2-hexenal or 2-heptanone was inhibited when benzaldehyde was mixed with these stimulants. At least 16 response patterns of these ORNs to nine chemicals were identified by SSRs, suggesting a high complexity of the cellular mechanisms underlying chemoreception in locusts.     

Structure and function of the antennal sensilla of the palm weevil Rhynchophorus palmarum (Coleoptera, Curculionidae)

The distribution, fine structure and function of the sensilla present on the antennal club of Rhynchophorus palmarum were studied. No sex dimorphism was observed. Scanning and transmission electron microscopy showed five types of hair-like structures, four of which were evenly distributed on the antennal club. Two types of hair (IV and V) showed wall pores, a characteristic of olfactory sensilla. The antenna numbers 11,190 +/- 3040 type IV and 7360 +/- 1500 type V hairs. Using single sensillum recording, we identified 17 types of olfactory receptor neurons (ORNs) on the basis of their responses to pheromone and host plant odors, triggering synergic behavioral responses. We characterized highly specific and sensitive ORNs tuned to the aggregation pheromone (18% ORNs; 0.01-1 ng response threshold) and to host plant odors such as ethyl acetate, ethanol, acetoin and guaiacol (10% ORNs; 1-10 ng response threshold). Eleven percent of the ORNs were more generalist, responding to several odors with low sensitivity. Nine percent of the ORNs showed a complex pattern of responses, being co-activated by the pheromone and plant odors. This suggests an interaction at the sensory neuron level between pheromone and plant odors, triggering synergic behavioral responses.     

Central projections of olfactory receptor neurons from single antennal and palpal sensilla in mosquitoes

In insects, olfactory receptor neurons (ORNs) are located in cuticular sensilla, that are present on the antennae and on the maxillary palps. Their axons project into spherical neuropil, the glomeruli, which are characteristic structures in the primary olfactory center throughout the animal kingdom. ORNs in insects often respond specifically to single odor compounds. The projection patterns of these neurons within the primary olfactory center, the antennal lobe, are, however, largely unknown.We developed a method to stain central projections of intact receptor neurons known to respond to host odor compounds in the malaria mosquito, Anopheles gambiae. Terminal arborizations from ORNs from antennal sensilla had only a few branches apparently restricted to a single glomerulus. Axonal arborizations of the different neurons originating from the same sensillum did not overlap.ORNs originating from maxillary palp sensilla all projected into a dorso-medial area in both the ipsi- and contralateral antennal lobe, which received in no case axon terminals from antennal receptor neurons. Staining of maxillary palp receptor neurons in a second mosquito species (Aedes aegypti) revealed unilateral arborizations in an area at a similar position as in An. gambiae.     

Maxillary palps are broad spectrum odorant detectors in Culex quinquefasciatus

A single type of olfactory sensilla on maxillary palps in many species of mosquitoes houses a very sensitive olfactory receptor neuron (ORN) for carbon dioxide reception. We performed extensive single sensillum recordings from this peg sensillum in Culex quinquefasciatus and have characterized the response threshold and kinetics for CO(2) reception, with a detection threshold less than the CO(2) concentration in the atmosphere. This ORN responded in a tonic mode to lower concentrations of CO(2), whereas higher concentrations generated a phasic-tonic mode of action potential firing. Sensillum potentials accurately represented the response magnitude and kinetics of carbon dioxide-elicited excitatory responses. Stimulation of these ORNs with human breath, a complex mixture of mosquito kairomones and up to 4.5% CO(2), elicited excitatory responses that were reliably detected by CO(2)-sensitive ORNs. Another ORN housed in these sensilla responded to 1-octen-3-ol and to various plant-derived compounds, particularly floral and green leaf volatiles. This ORN showed remarkable sensitivity to the natural enantiomer, (R)-(-)-1-octen-3-ol, rivaling pheromone-detecting ORNs in moths. Maximum neuronal response was elicited with a 10 ng dose. A biological, ecological role of maxillary palps in detection of plant- and nectar-related sources is proposed.     

蚊虫嗅觉识别的神经机制

蚊虫主要依赖嗅觉系统与外界环境进行化学信息交流。蚊虫通过嗅觉感受系统寻找食物、 配偶和产卵场所, 进而做出相应的行为反应。本文综述了近年来蚊虫嗅觉系统对气味信号神经传导机制的研究进展。蚊虫的嗅觉感器主要位于触角和下颚须, 触角上的毛形感器和锥形感器感受氨水、 乳酸、 羧酸类化合物等人体和其他动物释放的微量气味物质, 下颚须上的锥形感器则感受呼出的二氧化碳以及一些其他的挥发性物质; 蚊虫嗅觉感器内部有受体神经细胞, 其上分布有嗅觉受体蛋白, 蚊虫对外界环境的化学感受就是通过气味物质与这些受体蛋白互作而得以实现; 根据对不同气味物质的反应谱差异, 嗅觉神经细胞被分为不同的功能类型; 来自嗅觉神经细胞的神经信号进一步从外周传导至中枢神经中脑触角叶内的神经小球, 在此对信息进行初步的处理, 通过评估嗅觉神经细胞的反应和触角叶内的神经小球相应被激活的区域, 不同小球被分别命名; 最后, 神经信号继续整合, 由投射神经传向前脑, 最终引发一系列昆虫行为反应。这些研究从理论上剖析了气味信号在蚊虫嗅觉系统中的神经转导通路, 对于我们深刻理解蚊虫的嗅觉系统具有重要意义, 同时也有助于进一步理解其他昆虫甚至人类的气味识别机制及进行更深层次神经科学的探索。     

Physiology and antennal lobe projections of olfactory receptor neurons from sexually isomorphic sensilla on male <Emphasis Type="Italic">Heliothis virescens</Emphasis>

The neurophysiology and antennal lobe projections of olfactory receptor neurons (ORNs) within sexually isomorphic short trichoid sensilla of male Heliothis virescens (Noctuidae: Lepidoptera) were investigated using cut-sensillum recording and cobalt-lysine staining. A total of 202 sensilla were sorted into 14 possible sensillar categories based on odor responses and physiology of ORNs within. Seventy-two percent of the sensilla identified contained ORNs stimulated by conspecific odors. In addition, a large number of ORNs were specifically sensitive to ß-caryophyllene, a plant-derived volatile (N = 41). Axons originating from ORNs associated with individual sensilla were stained with cobalt lysine (N = 67) and traced to individual glomeruli in the antennal lobe. ORNs with responses to female sex pheromone components exhibited similar axonal projections as those previously described from ORNs in long sensilla trichodea in male H. virescens. Antennal lobe axonal arborizations of ORNs sensitive to hairpencil components were also located in glomeruli near the base of the antennal nerve, whilst those sensitive to plant odorants projected to more medial glomeruli. Comparisons with ORNs described from female H. virescens supports the notion that glomeruli at the base of the antennal nerve are associated with conspecific and interspecific odorants, whereas those located medially are associated with plant volatiles.     

Odor coding in the Drosophila antenna

Odor coding in the Drosophila antenna is examined by a functional analysis of individual olfactory receptor neurons (ORNs) in vivo. Sixteen distinct classes of ORNs, each with a unique response spectrum to a panel of 47 diverse odors, are identified by extracellular recordings. ORNs exhibit multiple modes of response dynamics: an individual neuron can show either excitatory or inhibitory responses, and can exhibit different modes of termination kinetics, when stimulated with different odors. The 16 ORN classes are combined in stereotyped configurations within seven functional types of basiconic sensilla. One sensillum type contains four ORNs and the others contain two neurons, combined according to a strict pairing rule. We provide a functional map of ORNs, showing that each ORN class is restricted to a particular spatial domain on the antennal surface.     

Characterization of olfactory sensilla of Stomoxys calcitrans and electrophysiological responses to odorant compounds associated with hosts and oviposition media

Stable flies, Stomoxys calcitrans L. (Diptera: Muscidae), are economically important biting flies that have caused billions of dollars in losses in the livestock industry. Field monitoring studies have indicated that olfaction plays an important role in host location. To further our understanding of stable fly olfaction, we examined the antennal morphology of adults using scanning electron microscopy techniques. Four major types of sensillum were found and classified as: (a) basiconic sensilla; (b) trichoid sensilla with three subtypes; (c) clavate sensilla, and (d) coeloconic sensilla. No significant differences between male and female flies in abundances (total numbers) of these sensillum types were observed, except for medium-sized trichoid sensilla. The distinctive pore structures found on the surface of basiconic and clavate sensilla suggest their olfactory functions. No wall pores were found in trichoid and coeloconic sensilla, which suggests that these two types of sensillum may function as mechano-receptors. Details of the distributions of different sensillum types located on the funicle of the fly antenna were also recorded. Electroantennogram results indicated significant antennal responses to host-associated compounds. The importance of stable fly olfaction relative to host and host environment seeking is discussed. This research provides valuable new information that will enhance future developments in integrated stable fly management.