Mate recognition and antennal morphology of Octodonta nipae (Coleoptera: Chrysomelidae) adults

The nipa palm hispid beetle, Octodonta nipae (Maulik) has been killing palm trees since its introduction into Hainan province, China, from Malaysia in 2001. It continues to spread within Hainan province, northeast to Fujian province, and northwest to Yunnan province within China. Knowledge on signals involved in mate location and recognition could help develop effective integrated pest management programs. In the present study, we first experimentally proved that antennae were essential in success of O. nipae mating. We then excised various segments/flagellomeres of adult male and female antennae and observed their mating behavior. Results revealed that the 5th to 9th flagellomeres, especially those of males, were important for the mating success. Finally, in an attempt to elucidate the types of antennal sensilla accountable for the mating success, morphology of O. nipae antennae was studied in detail with scanning electron microscopy. Six types of sensilla were distinguished: aporous sensilla trichodea (T1), multiporous sensilla trichodea (T2), aporous sensilla chaetica (Ch1), uniporous sensilla chaetica (Ch2), multiporous sensilla basiconica (B), and Böhm sensilla (Bm). Aporous sensilla trichodea is the most abundant; multiporous sensilla trichodea and sensilla basiconica are considered as olfactory receptors, and uniporous sensilla chaetica as gustatory receptor. Importance of flagellomeres 5–9 in mating success seemed to correspond to the abundance of sensilla on these segments.     

Antennal olfactory sensilla of the parasitoid fly,Pseudoperichaeta nigrolineata Walker (Diptera : Tachinidae)

The antennal sensilla of male and female Pseudoperichaeta nigrolineata Walker (Diptera: Tachinidae) were studied by scanning electron microscopy. Five types of sensilla were identified on the funicle. The trichoid sensilla are most conspicuous, with a characteristic distal curvature and wall pores. Basiconic types I and II sensilla show a small peg with a pitted surface. Basiconic type III sensilla can be distinguished from the preceding ones by the swelling of the distal region of the peg. The function of these sensilla is likely to be olfactory. Coeloconic sensilla consist of a short grooved peg sunk in a socket. The number and distribution of the sensilla of each type are described. Female antennae bear more basiconic sensilla than those of males. These results are compared with previously published studies on other muscoid species.     

黄脊竹蝗触角感器的电镜扫描观察

黄脊竹蝗是中国南方地区重要的竹子害虫,为了更好地理解黄脊竹蝗"趋尿行为"的生理生化机制,通过电镜扫描技术研究了黄脊竹蝗成虫触角感器的类型、数量、形态及分布特征,比较分析了其在雌、雄成虫间的差异。结果表明:黄脊竹蝗雌、雄成虫触角丝状,由1节柄节、1节梗节和23节鞭节构成,雌雄间触角长度及直径差异不显著(P>0.05);雌、雄成虫触角感器均有毛形感器Ⅰ、毛形感器Ⅱ、刺形感器、锥形感器Ⅰ、锥形感器Ⅱ和腔锥形感器6种;其中,锥形感器数量最多,约占感器总数的53%,主要分布在鞭节的第8～21亚节上;各类感器在雌、雄成虫间触角上的分布特征相似,雄成虫触角上感器总数、锥形和腔锥形感器数量显著多于雌成虫(P<0.05)。     

六斑月瓢虫触角及感觉器扫描电镜观察

[目的] 明确六斑月瓢虫雌雄成虫触角感觉器种类、分布及形态特征。[方法] 利用扫描电子显微镜对六斑月瓢虫雌、雄成虫触角形态及触角感受器超微结构进行观察。[结果] 六斑月瓢虫成虫触角由柄节、梗节和鞭节组成,柄节长度与宽度显著大于梗节长度与宽度;鞭节分为9个亚节,末端3节横向膨大呈锤状。雌雄成虫触角上共有8种感觉器:刺形感觉器(SC)、毛形感觉器(ST)、锥形感觉器(SB)、腔形感觉器(CaS)、钟形感觉器(CS)、哑铃形感觉器(DS)、香肠形感觉器(SS)及B?hm氏鬃毛感觉器(BB)。以毛形感觉器和刺形感觉器分布最广,遍布触角;B?hm氏鬃毛仅存在于触角柄节与梗节;触角鞭节第9亚节顶端密布7种触角感觉器。六斑月瓢虫雌雄成虫触角长度、触角感觉器类型及分布无显著差异。[结论] 六斑月瓢虫成虫触角上共有8种感觉器,其触角可能具有感知机械刺激、识别化学信息素及感受温湿度变化的作用。本研究为进一步了解六斑月瓢虫触角与其行为间的关系提供基础资料。     

Structure and distribution of antennal sensilla in Oranmorpha guerinii (Gervais, 1837) (Diplopoda,Polydesmida)

Detailed information on sensory organs of Diplopoda especially on antennal sensilla are still sparse and fragmentary. The present study on the antennae of Oranmorpha guerinii (Polydesmida, Paradoxosomatidae) utilizing scanning electron microscopy revealed the presence of six sensillar types: (1) apical cones, (2) sensilla trichodea, (3) sensilla microtrichodea, (4) sensilla chaetica, (5) sensilla basiconica bacilliformia, and (6) sensilla basiconica spiniformia. External structure and distribution of cuticular antennal sensilla are compared with data from other diplopod species. We moreover discuss possible functions of antennal sensilla in millipedes.     

Atlas of olfactory organs of Drosophila melanogaster: 1. Types,external organization,innervation and distribution of olfactory sensilla

The third antennal segment (funiculus) and the maxillary palp are the main and accessory olfactory sense organs of Drosophila melanogaster. Cryofixed antennae and palps revealed a superior preservation of the sensory dendrites and other cellular details as compared to conventional chemical fixation. Extensive cross-section series through funiculus and palp were studied in order to obtain as complete an evaluation as possible of the sensillar complement on these appendages. About 75% of all sensilla on the male and female funiculus were individually studied and their position on the antennal surface mapped. Dimensions of the cuticular apparatus of the various types of sensilla are provided as well as the number of innervating receptor neurons. Particular attention has been paid to the cuticular pores important for stimulus transport and to the sensory dendrites. On the funiculus surface, all sensilla have multiple wall pores: sensilla (s.) trichodea and s. basiconica are single-walled, s. coeloconica are double-walled. The distribution of s. trichodea and s. basiconica follows opposing gradients along a diagonal axis parallel to the axis of the arista from proximo-medial to disto-lateral. In this disto-lateral direction the density of s. trichodea increases while that of the s. basiconica decreases. S. trichodea occur in three subtypes with one, two or three receptor neurons. Basiconic sensilla can be subdivided into three subtypes of large s. basiconica (with two or four receptor neurons), three subtypes of thin s. basiconica (with mostly two, rarely four neurons), and one subtype of small s. basiconica with two receptor neurons. Large s. basiconica occur only in the most proximal region (the ‘LB-zone’); thin s. basiconica are most common in a belt that borders the LB-zone distally, while small s. basiconica are most numerous even further distally along the mentioned diagonal axis in between the s. trichodea. S. intermedia are single-walled, multiporous sensilla which combine features of s. trichodea and s. basiconica; they are found in two subtypes with two or three receptor neurons, in the same region where s. trichodea abound. The s. coeloconica are irregularly distributed over the funicular surface, and occur in two subtypes with two or three receptor neurons. Sexual dimorphism on the antenna is moderate, the female funiculus is a bit longer and carries a larger number of small s. basiconica and large s. basiconica of the LB-I subtype; the male funiculus, however, has more s. trichodea than the female. On the maxillary palp, besides mechanoreceptive s. chaetica, there are only s. basiconica with two receptor neurons. According to the fine structure of their sensory dendrites, three subtypes can be discriminated which are distributed in a random pattern. The functional significance of the described structures and distribution awaits future immunocytochemical and electrophysiological experiments.     

Sensilla of the antennal flagellum in Pseudaletia unipuncta (Haw.) (Lepidoptera: Noctuidae)

Seven sensilla were observed on the antennal flagellum of both sexes of Pseudaletia unipuncta (Haw.) (Lepidoptera : Noctuidae): chaetica Type I and Type II), styloconica, coeloconica, trichodea (Type 1a, b, c and Type II a, b), auricillica, nonporous and squamiformia. The major sexual dimorphism noted was the presence of Type la trichodea on the male antennae, suggesting that this sensillum may contain the receptor sites for the female sex pheromone. Differences in the size of sensilla coeloconica, auricillica and trichodea (Types Ib, IIb) were noted between sexes, being larger in females. Adults obtained from larvae fed on artificial diet generally had longer antennae and sensilla than those fed on young oat plants.     

The antennae and antennal sensilla of the giant looper,Boarmia (Ascotis) selenaria SchiffermÜller (Lepidoptera,Geometridae)*

The general morphology of the antennae and the antennal sensilla of both sexes of Boarmia (Ascotis) selenaria SchiffermÜller are described. The following types of sensilla were found: Bohm bristles and sensilla chaetica, trichodea, coeloconica, auricillica and styloconica. Antennal sexual dimorphism is marked, but mainly confined to the presence of long sensilla trichodea in males and the absence in females. The sensilla trichodea are the most abundant sensillum type.     

中红侧沟茧蜂触角感受器的扫描电镜观察

利用扫描电镜对中红侧沟茧蜂Microplitis mediator的触角感受器进行了观察,发现了6个类型的感器,分别为毛形感器、板形感器、刺形感器、钟形感器、锥形感器、腔锥形感器。其中,毛形感器具有2种形态,锥形感器具有4种形态。钟形感器仅分布于雌蜂的触角上,锥形感器Ⅲ和Ⅳ仅分布于雄蜂的触角上。结合感受器的形态、分布和已报道的触角电位反应数据,对各感受器的功能进行了推测。     

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。     

The structure of the antennae of the Florida Queen butterfly, Danaus gilippus berenice (Cramer)

Interest in the structure of the antennae of the Florida Queen butterfly arises from the finding that a pheromone is active in their courtship. Light and electron microscopic techniques were used to study the sensilla on the antennae and three types of sensilla with perforated walls were identified. The most common of these are short, thin-walled pegs which are distributed over most of the antennal surface. Long, curved, thin-walled pegs occur in patches on the inner medial antennal surface. Multiple coeloconic sensilla are present having up to 50 pegs in one sensillum. On the outer 28 flagellar subsegments there are two such sensilla per subsegment. In addition there are on the antennae long, thick-walled hairs which are mechanoreceptors and probably also contact chemoreceptors. Sunken pegs, the function of which is not known, occur on the antennae. Grooved sensilla were found with the electron microscope but could not be identified with the light microscope. There was no indication of sexual dimorphism in sensilla types or numbers on the antennae.     

Types of Antennal Sensilla of the Asian Corn Borer,Ostrinia furnacalis (Guenéee)

This study was carried out to investigate the types of sensilla and their distribution on the antennae of the Asian corn borer, Ostrinia furnacalis (Guenéee). O. furnacalis had six types of antennal sensilla: sensilla trichodea, sensilla chaetica, sensilla coeloconica, sensilla auricillica, sensilla styloconica and Böohms bristle. S. auricillica, single-walled multiporous sensilla, were presumed to be involved in chemical reception. S. coeloconica were double-walled, multiporous sensilla and could detect chemicals also. S. chaetica appeared to be mechano-receptors. S. styloconica were poreless and were thought to have thermo- and hygro-receptors. S. trichodea were single-walled chemosensilla and two subtypes were identified by transmission electron microscopy. The scape and the pedicel had Böohms bristles, which seem to function as mechanical stimulus receptors.     

红火蚁触角及其上感受器的扫描电镜观察

应用扫描电镜对采自我国广东吴川和广西南宁的红火蚁Solenopsis invicta Buren工蚁、有翅雌蚁和雄蚁触角的形态和感受器类型进行了研究。结果表明,工蚁、雌蚁和雄蚁的触角存在着较大的差异。工蚁和雌蚁的触角为膝状,末端2或3节膨大为棒状,雌蚁的触角11节,比工蚁(10节)的多1节。雄蚁的触角为线状,12节,末端没有棒状结构。工蚁和雌蚁的触角上共有7种感受器,分别为毛形、曲毛形、锥形、腔锥形、坛形、刺形感受器和Böhm氏鬃毛,前6种感受器大多集中在触角末端的棒节,棒节以外的各鞭节上主要是毛形感受器,Böhm氏鬃毛则分布于柄节和梗节的基部,鞭节上无此感受器。雄蚁触角上也有7种感受器,但其分布与工蚁的有较大差异,Böhm氏鬃毛的分布与工蚁和雌蚁的相同,锥形感受器分布在末端2节,坛形感受器分布在末端3节,其余的4种感受器较为均匀地分布在各鞭节,而不是聚集在端节。另外,新发现雄蚁中存在一种与已知的毛型感受器不同的超短毛状感受器,定名为超短毛感受器。最后,对红火蚁的触角及感受器在蚁群社会性行为中的作用进行了讨论。     

Ultrastructure of the antennal sensilla of the mayfly Baetis rhodani (Pictet) (Ephemeroptera : Baetidae)

The distribution and fine morphology of antennal sensilla of nymphal and adult mayfly, Baetis rhodani (Ephemeroptera : Baetidae), were examined. In the nymph, various kinds of sensilla (chaetica, basiconica, coeloconica and cuticular pits) are differently arranged on the antennal segments, whereas sensilla campaniformia delimit the distal border of the pedicel. A peculiar kind of sensillum basiconicum, named flat-tipped sensillum, is present along the entire antenna, even though in the flagellum it has a regular arrangement between the cuticular lobes that delimit the distal border of each article. In the subimago the scape and pedicel are profusely covered with microtrichia and scattered sensilla trichodea, whereas the flagellum shows cuticular ribs. Sensilla coeloconica are present along the ventral side of the flagellum. In the imago, the antenna is completely decorated with scales among which sensilla trichodea and sensilla coeloconica occasionally occur. As in the nymph, adult mayflies have a ring of sensilla campaniformia along the distal border of the pedicel. When compared with nymphal antennae, those of adults have fewer types of sensilla, presumably in relation to the short, non-feeding terrestrial life.     

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。     

Morphological and ultrastructural characterization of olfactory sensilla in Drosophila suzukii: Scanning and transmission electron microscopy

Drosophila suzukii is a serious horticultural and quarantine pest, damaging various berry crops. Although the active use of olfactory communication in D. suzukii is well-known, their olfactory sensory system has not been comprehensively reported. Therefore, the present study was carried out to understand the morphology, distribution and ultrastructure of olfactory sensilla present in the antennae and maxillary palps of D. suzukii, through scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The olfactory sensilla on the antennae of D. suzukii in both sexes could be classified into three major morphological types, basiconic, trichoid and coeloconic sensilla, according to their shapes. The antennal basiconic sensilla were further divided into three subtypes and the antennal trichoid sensilla into two subtypes, respectively, according to the size of individual sensillum. In contrast to the antennal olfactory sensilla showing diverse morphology, basiconic sensilla was the only type of olfactory sensilla in the maxillary palps of D. suzukii. The basiconic sensilla in the maxillary palps could be further classified into three subtypes, based on their size. Our SEM and TEM observations indicated that multiple nanoscale pores are present on the surface of all types of olfactory sensilla in the antennae and maxillary palps, except coeloconic sensilla. The difference in the morphological types and the distribution of olfactory sensilla suggests that their olfactory functions are different between antennae and maxillary palps in D. suzukii. The results of this study provide useful information for further studies to determine the function of olfactory sensilla in D. suzukii and to understand their chemical communication system.     

Functional anatomy of sensory structures on the antennae of Psylliodes chrysocephala L. (Coleoptera: Chrysomelidae)

The ultrastructure and distribution of sensilla on the antennae of the cabbage stem flea beetle, Psylliodes chrysocephala, were investigated using scanning and transmission electron microscopy techniques. Eight different sensillar types were distinguished. These were; hair plate sensilla, sensilla chaetica, three types of sensilla trichodea, sensilla basiconica, grooved peg sensilla and styloconic sensilla. The sensilla chaetica are known to be gustatory receptors. Ultrastructure indicates that the hair plate sensilla and sensilla trichodea type one are probably mechanoreceptors, whilst the sensilla styloconica are probably thermo-hygro receptors. These thermo-hygroreceptors are unusual in that they are innervated by two sensory cells (one hygroreceptor and one thermoreceptor) rather than the more usual triad. The remaining four sensillar types all have a porous hair shaft, indicating an olfactory role. One of these (the grooved peg sensillum) may also have a thermoreceptive function. No sexual dimorphism was found in the structure, number or distribution of the antennal sensilla.     

松突圆蚧雄成虫触角感器的扫描电镜观察

松突圆蚧(Hemiberlesia pitysophila Takagi)是我国南方重要的外来林业害虫。本研究利用扫描电镜对该蚧雄成虫的触角形态和感器进行了观察。结果表明:松突圆蚧雄成虫触角呈线状,由柄节、梗节和鞭节组成,共10节。触角感器共有5种,分别为Bhm氏鬃毛、毛形感器、乳头形感器、锥形感器、火柴形感器,其中,火柴形感器为首次在松突圆蚧雄成虫触角上发现并描述。不同感器在触角各节的数量和分布各不相同,其中,毛形感器数量最多,分布最广,乳头形感器次之,火柴形感器最少。此外,根据感器的分布、形态特征,结合已有的文献描述,推测了感器可能的功能。     

Morphology of antennal sensilla of the brown spruce longhorn beetle,Tetropium fuscum (Fabr.) (Coleoptera: Cerambycidae)

The antennal sensilla of the brown spruce longhorn beetle, Tetropium fuscum (Fabr.) (Coleoptera: Cerambycidae) were examined with particular focus on the sensilla present on the apical flagellomere. T. fuscum antennae are composed of 11 segments, namely the scape, pedicel, and nine flagellomeres. Nine types of sensilla were observed: three types of sensilla chaetica, sensilla trichodea, two types of sensilla basiconica, grooved peg sensilla, thick-walled sensilla, and Böhm bristles. Seven of these types were present on the apical flagellomere, the exceptions were sensilla chaetica type 3 and Böhm bristles. There were no significant differences in the distribution or density of sensilla present on the ninth flagellomere of males and females, except that males had significantly more sensilla chaetica type 1, which are put forward as the putative contact chemoreceptors for T. fuscum.