Ultrastructure of antennal sensilla of the peach aphid Myzus persicae Sulzer, 1776

The antennal sensilla of alate Myzus persicae were mapped using transmission electron microscopy and the ultrastructure of sensilla trichoidea, coeloconica, and placoidea are described. Trichoid sensilla, located on the tip of the antennae, are innervated by 2–4 neurons, with some outer dendrites reaching the distal end of the hair. Coeloconic sensilla in primary rhinaria are of two morphological types, both equipped with two dendrites. Dendrites of Type II coeloconic sensilla are enveloped in the dendrite sheath, containing the sensillum lymph. In sensilla coeloconica of Type I, instead, dendrites are enclosed by an electron opaque solid cuticle, with no space left for the sensillum lymph. The ultrastructure of big placoid sensillum reveals the presence of three groups of neurons, with 2–3 dendrites in each neuron group, while both small placoid sensilla are equipped with a single group of neurons, consisting of three dendrites. Both large and small placoid sensilla bear multiple pores on the outer cuticle. The function of these sensilla is also discussed. J. Morphol. 276:219–227, 2015. © 2014 Wiley Periodicals, Inc.     

昆虫单个感觉器记录技术研究进展

单感器记录技术是一种昆虫细胞外电生理技术,可以测量昆虫单个感受器对刺激物的电生理反应。该技术有助于探明昆虫嗅觉和味觉感受器对不同信息化合物的电生理响应机制,将单感器记录技术与其他技术相结合,不仅可以阐明昆虫嗅觉反应的分子机制,还可以研制昆虫行为调节剂、检测挥发性有机化合物的生物传感器。本文介绍了单感器记录仪的结构和昆虫单感器记录的原理,并对单感器记录技术在昆虫学研究方面的应用进行了综述,以期为探明昆虫感受化学信息物质的机理和应用提供依据。     

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.     

EXPRESSION OF SNMP1 AND SNMP2 GENES IN ANTENNAL SENSILLA OF Spodoptera exigua (HÜBNER)

Sensory neuron membrane proteins (SNMPs) are olfactory‐specific, two‐transmembrane proteins. Previous publications reported that SNMP1 is expressed on the dendrite membrane of pheromone‐sensitive neurons in Heliothis virescens and is an essential cofactor for pheromone detection in Drosophila. In this study, we cloned two SNMP genes (GenBank accession nos. JX469106 and JX469107) from the antenna of the beet armyworm moth Spodoptera exigua (Lepidoptera: Hübner). These SNMP genes are classified into two highly conserved subclades, indicating their importance in physiological activity of lepidopteran insects. SexiSNMP1 is antenna‐specific in male and female adults, while SexiSNMP2 is antenna‐abundant but also expressed in other chemosensory tissues, particularly proboscises and maxillary palps of adults both sexes. In situ hybridization revealed that both SNMPs are broadly expressed in long and short trichoid and basiconic sensilla. We infer that SNMP1 and SNMP2 act in the detection of the sex pheromone and general odorants.     

Functional validation of the carbon dioxide receptor in labial palps of Helicoverpa armigera moths

Adult moths possess an organ in their labial palps, the labial-palp pit organ, which is specialized for sensing carbon dioxide (CO₂). They use CO₂ as a cue to detect healthy plants and find food or lay eggs on them. The molecular bases of the CO₂ receptor in Drosophila melanogaster and Aedes aegypti have been reported, but the molecular mechanisms of the CO₂ receptor in Lepidoptera remains elusive. In this study, we first re-examined three putative Helicoverpa armigera CO₂ gustatory receptor genes (HarmGr1, HarmGr2, and HarmGr3), and then analyzed expression patterns of them. RT-PCR results verified they were predominantly expressed in the labial palps of H. armigera. Thus, we used in situ hybridization to localize the expression of three genes in the labial palps. We found that all three genes were co-expressed in the same cells of the labial palps. Next, we employed the Xenopus laevis oocyte expression system and the two-electrode voltage-clamp recording to study the function of the three genes. Results showed that only oocytes co-expressing HarmGr1 and HarmGr3 or co-expressing HarmGr1, HarmGr2 and HarmGr3 gave robust responses to NaHCO₃. Finally, we confirmed that the sensory cells in labial palps of both females and males show dose dependent responses to CO₂ stimuli by using single sensillum recording. Our work uncovers that HarmGr1 and HarmGr3 are indispensable and sufficient for CO₂ sensing in labial palps of H. armigera.     

芒果横线尾夜蛾触角感觉器扫描电镜观察

采用扫描电镜技术对芒果横线尾夜蛾触角感觉器进行了观察和研究。结果表明,芒果横线尾夜蛾成虫触角上有5种类型的感觉器,分别为毛形感觉器、刺形感觉器、锥形感觉器、腔锥形感觉器和柱形感觉器。这些感觉器在成虫中存在雌雄二型性,其中雌雄虫都具有毛形感觉器Ⅰ型和Ⅱ型、刺形感觉器、锥形感觉器Ⅰ型和腔锥形感觉器等四种类型的感觉器,其中以毛形感觉器最多,约占全部感觉器的72%。而锥形Ⅱ型和柱形感觉器只存在于雄虫触角上。     

蜚蠊棘-钟形感器冲动发放的适应

本实验研究蜚蠊后胸足胫节棘-钾形感器冲动发放的适应特性,用探针向棘窝方向推棘以兴奋感觉神经元,用胞外电极记录神经冲动的发放,显示明显的适应现象.用计算机对冲动信号进行分析作图可得时间-瞬时频率曲线,该曲线呈负幂函数分布并可用y=B(?)公式描述,其中k为回归系数,表示该感器的适应速率,棘移动距离可影响k值,棘移动距离越长,k值越大,表示适应速率减慢.高频率移动棘可使反应发生动态和稳态两方面的变化;前者显示后续反应的脉冲个数的减少,后者则显示k值的降低,意味着适应的加快.     

分月扇舟蛾触角感觉器的扫描电镜观察

利用扫描电镜对分月扇舟蛾Clostera anastomosis(L.)成虫触角感觉器的形态、结构进行了观察。扫描电镜观察结果表明,分月扇舟蛾触角由柄节、梗节和鞭节组成,触角外侧面覆盖有鳞片,绝大部分触角感觉器位于触角的腹面和外侧面。雌、雄蛾触角上均存在以下8种感觉器,即毛形感器、刺形感器、腔形感器、腔锥形感器、栓锥形感器、锥形感器、柱形感器和鳞形感器。各种感觉器在雌、雄蛾触角上的分布大体相同,但数量有明显的区别。     

中国黄蚜小蜂属二新种(膜翅目:蚜小蜂科)

本文记述了在园林害虫天敌普查中从蚧虫内饲养出的我国黄蚜小蜂属Aphytis Howard两新种。模式标本存广东省昆虫研究所。 1、樟雪蚧黄蚜小蜂Aphytis chionaspis Ren,新种(图1—8) 雌:长0.75—1.05毫米。体黄色。头部复眼紫红色。触角柄节淡黄色,鞭节微暗色。头、胸、腹部刚毛淡褐色。小盾片后端缘中部黑褐色。胸部腹板暗色、叉状纵干黑褐色。翅透明,前翅翅基片下方一短的横条骨片褐色。缘脉与亚缘脉连接处之下方暗色,后缘褶淡褐色。前足跗节暗色;中、后足胫节、跗节暗色;后足腿节腹缘淡色。产卵管淡褐色。     

External structure of the sensillum capitulum,a hygro- and thermoreceptive sensillum of the cockroach,Periplaneta americana

Summary The antennal hygro- and thermoreceptive sensillum (sensillum capitulum) of the cockraoch, Periplaneta americana, has been identified electrophysiologically and examined by scanning electron microscopy. It appears basiconic and has a characteristic cuticular apparatus; a mushroom-shaped inner stem and a non-perforated outer wall. The head of the inner stem, which is a cap of about 0.5 m diameter, protrudes from the distal margin of the outer wall. The inner stem is not perforated, though in some cases a tiny hollow is observed in the apex of the cap. This kind of cuticular apparatus is not found in other sensilla and may be modality-specific to hygro- and/or thermoreception. The sensillum capitulum occurs singly on the distal part of each alternating segment of the flagellum and on each segment of some distal meristal segments.Supported by Grant-in-Aid for Special Project Research Mechanism of animal behavior from the Ministry of Education (Japan)     

Sensilla on the aedeagus of the ground beetle Carabus (Ohomopterus) arrowianus arrowianus (Breuning) (Coleoptera: Carabidae)

Sensilla on the aedeagus of the ground beetle Carabus (Ohomopterus) arrowianus arrowianus (Breuning) were investigated by scanning electron microscopy. On the aedeagus, a total of six types of sensillum were confirmed: five basiconic and one coeloconic. The external features and distributional patterns of the sensilla are described.     

茶银尺蠖雄蛾触角的扫描电镜观察

本文采用扫描电镜对茶银尺蠖Scopula subpunctaria Herrich-Schaeffer雄蛾触角感受器进行了外部形态的观察和研究。结果表明,茶银尺蠖雄蛾的触角感受器主要有毛形感受器、鳞形感受器和刺形感受器3种。描述了各种感受器的形态特征和着生规律,对其主要生理功能进行了分析和讨论。     

Reduction of mechanical sensitivity in an insect mechanoreceptor correlated with destruction of its tubular body

Summary The modified cilium (dendrite) of epithelial mechanoreceptors of insects contains microtubules in different arrangements: (1) microtubules distributed over the entire receptor and not fixed in a special configuration, therefore called free microtubules, (2) densely packed, interconnected microtubules called the tubular body, and (3) 9 doublet microtubules. These groups of microtubules have been discussed in relation to mechanotransduction.In a preceding paper the free microtubules were proved to be not involved in mechanotransduction. In this paper the hypothesis is examined that the tubular body may be essential to mechanotransduction. For this purpose the effect of the microtubule-disassembling drug vinblastine on both the tubular body and the sensitivity is examined in a femoral mechanoreceptor of the cricket Acheta domesticus.After 6- to 26-h exposure to vinblastine the tubular body is partially or totally destroyed. Simultaneously, mechanical sensitivity decays to zero. In contrast, the pacemaker property for nerve impulses of the apical dendritic segment is only slightly altered. We conclude from these results that the tubular body is essential to mechanotransduction. Three experiments in which a (small) response persisted, despite a totally destroyed tubular body, suggest that receptor potentials can in principle be evoked without an intact tubular body.In addition to the irreversible reduction of receptor sensitivity, vinblastine causes a reversible reduction during repetitive stimulation. This adaptation is supposed to be the consequence of altered properties of the tubular body.     

Changes in taste receptor cell sensitivity in a polyphagous caterpillar reflect carbohydrate but not protein imbalance

Caterpillars of the polyphagous arctiid, Grammia geneura, have a single cell in the medial galeal sensillum that responds to some sugars and to some amino acids. After conditioning on artificial diet containing unbalanced amounts of carbohydrate and protein, the responses of this cell alter. After protein-biased food it increases slightly, but after carbohydrate-biased food it decreases. Responses to both sucrose and amino acids change in the same direction and the changes would not provide the information necessary to redress a shortage of protein. The lateral galeal sensillum contains one cell that responds to fructose and another responding to some amino acids. The responses of each of these cells in the lateral sensillum are not consistently affected by conditioning diets. After conditioning for 20 h on a protein- or carbohydrate-biased diet, the insects started to feed without delay if offered carbohydrate-biased diet, but only after a pause if given protein-biased diet. This occurred irrespective of the conditioning diet. The duration of the first feeding bout was also longer on carbohydrate-biased diet and the longest bouts followed protein-biased conditioning.     

Identification of oviposition attractants for the sandfly Lutzomyia longipalpis (Diptera: Psychodidae) in volatiles of faeces from vertebrates

Abstract. Extracts of volatiles from rabbit and chicken faeces preferentially attracted gravid sandflies, Lutzomyia longipalpis (Lutz and Neiva), in an oviposition bioassay. In electrophysiology experiments, the same extracts selectively stimulated two olfactory cells while inhibiting another in ascoid sensilla on the antennae of these flies. Analysis of faeces volatiles by gas chromatography linked to ascoid sensillum recording revealed two early eluting electrophysiologically active components of rabbit faeces. These active compounds were identified in both rabbit and chicken faeces volatile extracts by gas chromatography -mass spectrometry as hexanal and 2-methyl-2-butanol. Hexanal stimulated one cell type and inhibited another, whereas 2-methyl-2-butanol stimulated a third cell type. A 1:l mixture of synthetic hexanal and 2-methyl-2-butanol elicited the same targeted oviposition response from gravid females on the treatment septum of the bioassay as did the total volatile extract of rabbit or chicken faeces.
The monoterpenes α(+)-pinene (plus some optical and positional isomers) and a-terpinene activated a separate cell type, whereas benzaldehyde stimulated the same receptor as hexanal, but with a higher threshold. Furthermore, an olfactory cell selectively tuned to the perception of the male sex pheromone of this species was also found in the ascoid sensillum.     

稻虱红螯蜂触角感受器的扫描电镜观察

扫描电镜观察表明,稻虱红螯蜂Haplogonatopus japonicus Esaki et Hashimoto触角上存在6种感受器,其中刺形感器、锥形感器Ⅳ型、柱形感器Ⅱ型和Bhm氏鬃毛雌、雄都有,仅数量和分布上存在差异;毛形感器Ⅱ型、Ⅲ型,锥形感器Ⅰ型、Ⅱ型、Ⅲ型,柱形感器Ⅰ和锥形乳头状感器仅分布于雌蜂触角;而毛形感器Ⅰ型,锥形感器Ⅴ型仅见于雄蜂触角。对触角感受器的形态进行了描述,并对部分感器功能进行了讨论。     

松墨天牛成虫头部感受器超微结构的观察

扫描电镜观察表明 ,松墨天牛MonochamusalternatusHope成虫头部存在 1 1种感受器。触角有 8种 ,下颚须和下唇须有 6种。栓锥感受器Ⅰ型、毛形感受器Ⅰ型及刺形感受器为触角、下颚须和下唇须共有。触角特有栓锥感受器Ⅱ型、毛形感受器Ⅱ型、锥形感受器以及柱形感受器Ⅰ型和Ⅱ型。下颚须及下唇须特有钟形感受器、坛形感受器和板形感受器。松墨天牛成虫触角感受器在种类、数量和分布上存在性别差异 ,雌雄虫的下颚须和下唇须感受器数量有所不同。     

Effect of [His7]-corazonin on the number of antennal sensilla in Locusta migratoria

Abstract.  Certain types of antennal sensilla are known to be more abundant in solitarious individuals than in gregarious ones in the migratory locust, Locusta migratoria . We tested the hypothesis that injection of a neurohormone, [His⁷]-corazonin, into isolated-reared nymphs of this species mimics the effect of crowding on the frequencies of various types of antennal sensilla. One nmol of the hormone was injected into nymphs on two occasions, on the third days of the second and third stadia, respectively. Upon adult emergence, the numbers of different types of sensilla on the eighth antennal segment were compared with those of oil-injected controls. [His⁷]-corazonin did not influence the numbers of basiconic sensilla type A, basiconic sensilla type B and trichoid sensilla significantly compared to oil-injected controls. However, the number of coeloconic sensilla was reduced significantly by the hormone injections. Because the length of the antennal segment was not affected by the hormone injection, it appears that the hormone influenced the development of coeloconic sensilla. The results support the hypothesis tested and are consistent with the idea that [His⁷]-corazonin plays an important role in the control of phase polymorphism in L. migratoria .     

悬铃木方翅网蝽触角感器扫描电镜观察

利用扫描电镜对悬铃木方翅网蝽Corythucha ciliata(Say)雌、雄成虫触角背面和腹面进行观察。结果表明:悬铃木方翅网蝽触角为棒状,共4节,分为柄节、梗节和鞭节。触角上共有4种感器,分别为刺型感器、锥形感器、毛型感器和芽型感器;这些感器不存在性二型现象。其中,刺型感器分为大刺型感器和小刺型感器2种类型;芽型感器首次在异翅亚目昆虫触角上发现。雄成虫触角感器数量明显多于雌成虫,不同类型的感器在触角各节上的数量与分布各不相同。     

烟草甲触角感器的扫描电镜观察

利用扫描电镜观察烟草甲Lasioderma serricorne(Fabricius)成虫触角感器的形态和分布。结果表明,烟草甲成虫触角由柄节、梗节和鞭节组成,其中鞭节由9个亚节组成;在触角上共观察到毛形感器、刺形感器、锥形感器Ⅰ、锥形感器Ⅱ、锥形感器Ⅲ、锥形感器Ⅳ、钟形感器、B hm氏鬃毛和球状感器9种感器类型,其中锥形感器Ⅳ、钟形感器、B hm氏鬃毛和球状感器为新发现的烟草甲触角感器。此外,还讨论感器结构与功能的关系。