External morphology of antennal sensilla of four species of adult flea beetles (Coleoptera : chrysomelidae : alticinae)

External morphology of antennal sensilla of both sexes of Phyllotetra cruciferae (Goeze) and Psylloides punctulata Melsh, both of which feed on the mustard family Cruciferae, and Epitrix cucumeris (Harris) and Psylloides affinis (Paykell), both of which feed on the nightshade family Solanaceae, was studied using scanning electron microscopy. All belong to Alticinae (Coleoptera : Chrysomelidae). The number and distribution of antennal sensilla were also determined. Eight types of sensilla could be distinguished on the flagella of the species examined: sensilla chaetica; sensilla trichodea I and II; long sensilla basiconica I and II; and short sensilla basiconica I, II and III. The sensilla chaetica are probable tactile mechanosensilla, whereas both types of sensilla trichodea and long sensilla basiconica likely function in olfaction. Suggested functions for the short sensilla basiconica I, II and III include hygro-/thermoreception and chemoreception.The lack of sexual dimorphism in antennal structure and in types as well as number of sensilla, indicates that the sensilla probably have similar functions in both sexes. Probably most of the antennal olfactory sensilla are involved in host location and recognition. Any correlation between number of a particular type of sensillum or total number of all types and general host preference is not apparent.     

Neotropical harvestmen (Arachnida,Opiliones) use sexually dimorphic glands to spread chemicals in the environment

Sexually dimorphic glands have convergently appeared in animals and are often responsible for the production of pheromones. In the suborder Laniatores of the order Opiliones (Arachnida), glands of such type are widespread, but there is not a single paper on how they are used. Using Scanning Electron Microscopy and a behavioral approach, we describe glandular openings and how these glands are used, in the harvestmen Gryne perlata and Gryne coccinelloides (Cosmetidae). Males of these two species have glandular openings on the metatarsi of legs I and on the metatarsi IV. Males were shown rubbing the glands of the metatarsi I against their other legs, whereas glands on the metatarsi IV are gently touched on the substrate or rubbed either against other legs, or against the substrate. Not all behaviors were seen in both species.     

黑肩绿盲蝽外生殖器及其感器的超微结构

黑肩绿盲蝽Cyrtorhinus lividipennis Reuter是稻飞虱重要天敌之一.为分析黑肩绿盲蝽成虫生殖器上与生殖有关的感器类型,本文通过扫描电镜对黑肩绿盲蝽雌成虫交配孔和产卵器,雄成虫交配器感器分布进行了观察.结果表明,黑肩绿盲蝽雌成虫交配孔有毛形感器Ⅱ(TSⅡ)和锥形感器Ⅱ(BSⅡ)2种感器;产卵器上...     

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.     

Surface structures of the antenna of Mantophasmatodea (Insecta)

The cuticular fine structure of the antenna in Mantophasmatodea (Austrophasmatidae: Hemilobophasma montaguense, Austrophasma gansbaaiense) is described based on SEM images. The armature of sensilla (=s.) on the basiflagellum (14 basal flagellomeres, the distal ones of which are subdivided) and distiflagellum (7 distal flagellomeres) differs strongly. A basiflagellomere has a sporadic vestiture of prominent s. chaetica B as well as distal s. scolopidia and scattered s. coeloconica. The distiflagellum also bears scattered s. chaetica B and s. coeloconica but is also densely covered with sensilla of various other types: numerous s. trichodea and s. basiconica, sporadic s. coelocapitula, and a probably new type of branched sensilla; the distiflagellum is probably the main sensory region, including gustatory and olfactory chemoreception, mechanoreception, and hygroreception. The scape and pedicel also bear s. chaetica B, and s. chaetica A arranged in 4 (scape) or 2 (pedicel) hair-plates. Terminal s. campaniformia are only found on the pedicel. A ‘dark spot’ is present apically on distiflagellomeres 6 (as reported previously) and 1. The two spots are of similar structure and are possibly associated with glands; each comprises a complicated external aperture and a larger internal pouch enclosing a cavity; projections protrude from the pouch walls into the cavity. The surface structure of the basiflagellomeres shows differences that are possibly species specific. An overview is given on antennal apomorphies in Mantophasmatodea.     

松褐天牛触角感器电镜扫描和触角电位反应

应用扫描电镜对松褐天牛的触角感器进行扫描观察,并测定了触角对松树主要挥发物的电生理反应.松褐天牛触角上共有7种感器,即毛形感器、锥形感器、指形感器、棒形感器、瓶形感器、芽形感器以及刺形感器,以毛形和锥形感器的数量最丰富.其中毛形感器和锥形感器各有3个型,指形感器有2个型.毛Ⅱ、毛Ⅲ型和锥Ⅰ、锥Ⅱ型感器表皮结构具有深的纵刻纹,具有嗅觉感器的典型特征.同时对各种感器的数量、长度及分布特点等作了描述.电生理研究结果表明,几种供试化合物及其混合物均能引起松褐天牛雌、雄成虫较强的电生理反应;松褐天牛触角不同部位的EAG反应存在显著差异;剂量试验表明,松褐天牛成虫触角对不同浓度的α-Pinene的EAG反应存在一定的规律性.     

Ultrastructure of antennal sense organs of small ermine moths,Yponomeuta spp. (Lepidoptera : Yponomeutidae)

The ultrastructure of antennal sensilla was investigated in males and females of 5 European Yponomeuta species. Three types of olfactory sensilla could be distinguished, i.e. sensilla trichodea, sensilla basiconica, and sensilla coeloconica. Sexual dimorphism in the number of cells innervating sensilla trichodea could be established in 3 species. Most of these sensilla in males of Y. vigintipunctatus, Y. rorellus, and Y. cagnagellus are associated with 3 sensory cells, whereas in females of these species these sensilla contain 2 sensory cells. In both males and females of Y. padeltus and Y. malinellus, the great majority of the sensilla trichodea is innervated by 3 cells. So-called sensilla chaetica type 1 show features typical of a combined mechano/contact-chemoreceptor. No structures indicating a sensory function were found in sensilla chaetica type 11. Sensilla styloconica contain 3 cells, the dendritic outer segment of one being lamellated; most likely, these cells have a thermo- and hygroreceptive function. The findings concerning the olfactory sensilla are discussed in the context of olfactory communication and reproductive isolation in European Yponomeuta.     

Localization of cGMP immunoreactivity and of soluble guanylyl cyclase in antennal sensilla of the hawkmoth Manduca sexta

The intracellular messenger cGMP (cyclic guanosine monophosphate) has been suggested to play a role in olfactory transduction in both invertebrates and vertebrates, but its cellular location within the olfactory system has remained elusive. We used cGMP immunocytochemistry to determine which antennal cells of the hawkmoth Manduca sexta are cGMP immunoreactive in the absence of pheromone. We then tested which antennal cells increase cGMP levels in response to nitric oxide (NO) and to long pheromonal stimuli, which the male encounters close to a calling female moth. In addition, we used in situ hybridization to determine which antennal cells express NO-sensitive soluble guanylyl cyclase. In response to long pheromonal stimuli with NO donors present, cGMP concentrations change in at least a subpopulation of pheromone-sensitive olfactory receptor neurons. These changes in cGMP concentrations in pheromone-dependent olfactory receptor neurons cannot be mimicked by the addition of NO donors in the absence of pheromone. NO stimulates sensilla chaetica type I and II, but not pheromone-sensitive trichoid sensilla, to high levels of cGMP accumulation as detected by immunocytochemistry. In situ hybridizations show that sensilla chaetica, but not sensilla trichodea, express detectable levels of mRNA coding for soluble guanylyl cyclase. These results suggest that intracellular rises in cGMP concentrations play a role in information processing in a subpopulation of pheromone-sensitive sensilla in Manduca sexta antennae, mediated by an NO-sensitive mechanism, but not an NO-dependent soluble guanylyl cyclase.     

豆野螟触角感器的电镜超微结构及嗅觉功能

本文利用扫描电镜(SEM)和触角电位仪(EAG)对豆野螟Maruca Testulalis (Geyer)触角感器的结构其及嗅觉功能进行了研究。豆野螟雌、雄成虫触角外部形态结构扫描的结果表明,豆野螟雌成虫触角上存在有毛形感器、刺形感器、腔锥形感器、耳形感器和栓锥形感器5种,雄成虫触角除上述5种感器外,还分布有柱形感器。以基部（触角的1/3）、中部（触角的1/3）和端部（触角的1/3）为单位,对雌、雄成虫触角节的各种类型感器数量进行统计,结果表明毛形感器、腔锥形感器、耳形感器在雌和雄虫触角上的分布都存在极其显著的差异。测定了豆野螟雄虫触角对性信息素化合物反,反-10,12-十六碳二烯醛和反,反-10,12-十六碳二烯-1-醇以及雌虫触角对植物挥发性化合物顺-3-己烯-乙酸酯和芳樟醇的EAG反应感应部位,结果表明EAG反应强弱与感器数量之间不存在明显的线性相关;对性信息素和植物挥发物有反应的触角感器在触角上的分布存在差异,对信息素反应的感器主要分布在触角鞭节的顶端24小节内(约占触角的1/3),而对植物挥发性化合物反应的感器则分布于触角鞭节顶端48小节内(约占触角的2/3)。     

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.     

Morphology and distribution of antennal sensilla in the pine wood nematode insect vectors Monochamus alternatus Hope and Monochamus saltuarius Gebler (Coleoptera: Cerambycidae)

As insect vectors of pine wood nematodes, Monochamus alternatus Hope and Monochamus saltuarius Gebler have different levels of attractiveness to semiochemicals. Although active use of chemical communication in both species is well known, there was no report on the differences in morphology and distribution of antennal sensilla between the two Monochamus species. The present study was carried out to explore the morphology, distribution, and ultrastructure of antennal sensilla of the two species using scanning and transmission electron microscopy. The overall shapes of the antennae were not different between M. alternatus and M. saltuarius. However, both M. alternatus and M. saltuarius exhibited sexual dimorphism overall. The antennae of each species were composed of the scape, pedicel, and nine flagellomeres, with four morphological types of sensilla: trichodea, basiconica, chaetica, and coeloconica. The four types occurred in varying numbers and distributions. The sensilla chaetica type was the most abundant in both species. Three types of sensilla (trichodea, basiconica, and chaetica) could be subdivided according to the two Monochamus species; sensilla trichodea could be divided into two subtypes, and sensilla basiconica and sensilla chaetica into three. All sensilla basiconica subtypes were multiporous, indicating that their primary function was olfactory. Sensilla trichodea subtype 2 was uniporous, indicating that the function of these sensilla might be gustatory. The morphological information obtained in our study provides a basis for future investigation of the sensory physiological function of each type of sensilla in the two species.     

The chemosensilla on tarsi of Locusta migratoria (Orthoptera: Acrididae): Distribution,ultrastructure, expression of chemosensory proteins

The chemosensilla on the tarsi of Locusta migratoria were mapped using light microscopy, as well as scanning and transmission electron microscopy. Only chemosensilla chaetica were found on the tarsi. On the basis of their ultrastructure, these can be grouped into three main subtypes: short, long, and sunken sensilla chaetica. Short sensilla chaetica can be further divided into two groups containing 6 or 7 neurons. Long sensilla chaetica are mainly located on the lateral surface of the tarsi. Short sensilla chaetica were mainly found on the dorsal surface of the tarsi. Sunken sensilla chaetica were only found on the ventral surface, such as the pulvilli and arolium. Immunocytochemical localization of chemosensory protein (CSP) was performed on ultrathin sections of chemosensilla on tarsi. The antiserum against LmigCSP‐II intensively labeled all three types of sensilla chaetica. Gold granules were concentrated in the outer sensillum lymph surrounding the dendrite sheath, while the inner sensillum lymph containing dendrite branches was never labeled. Massive labeling with the anti‐LmigCSP‐II was also found in cuticle of the pulvilli on the ventral surface of tarsi. J. Morphol. 2009. © 2009 Wiley‐Liss, Inc.     

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.     

Comparison of antennal sensilla of Anaphes victus and A. listronoti (Hymenoptera, Mymaridae), egg parasitoids of Curculionidae

Antennal sensilla were compared in females and males of two sympatric mymarid Hymenoptera, Anaphes victus and A. listronoti which are, respectively, solitary and gregarious parasitoids of eggs of the carrot weevil Listronotus oregonensis (Coleoptera, Curculionidae). Both species are morphologically very similar in the area where they are sympatric. The external morphology of the sensilla was studied using scanning electron microscopy. Female antennae have seven different types of sensilla, morphologically similar in the two species: trichoid sensilla, which are putative mechanosensilla, sensilla chaetica types 1, 3 and 4, which are presumably contact chemosensilla, and sensilla chaetica type 2 and basiconic and placoid sensilla, which are presumed to be olfactory sensilla. The major difference between the two species is the number of sensilla chaetica type 4, of which 6–9 are found on the antennal club in A. victus, while 10–12 are present in A. listronoti. The antennae of the males of both species are similar in morphology and in the number and distribution of their four types of sensilla, i.e. trichoid sensilla, sensilla chaetica type 1 and basiconic and placoid sensilla. Accepted: 23 November 1998     

Comparison of the antennal sensilla of females of four fig-wasps associated with Ficus auriculata

A comparison was performed of the antennal sensilla of females of four chalcid wasp species Ceratosolen emarginatus Mayr, 1906, Sycophaga sp., Philotrypesis longicaudata Mayr, 1906, and Sycoscapter roxburghi Joseph, 1957, which are specific and obligatory associated with Ficus auriculata (Lour, 1790). The four species exhibit different oviposition strategies in the fig ovules where their offspring hatch and develop. Antennal sensilla morphology was evaluated using scanning electron microscopy. Females of the four species present 11 morphologically similar types of sensilla: trichoid sensilla, sensilla obscura, chaetica sensilla 1 and 2, which all have mechanosensory functions; uniporous basiconic sensilla, which are presumably contact chemosensilla; basiconic capitate peg sensilla, coeloconic sensilla 1, multiporous basiconic and placoid sensilla, which may be regarded as olfactory sensilla, and coeloconic sensilla 2 and 3, which are presumed to be proprioreceptors or pressure receptors. The four species have significant differences in the abundance and arrangement of trichoid sensilla and chaetica sensilla 1 on the flagellum. The coeloconic sensilla and sensilla obscura only occur on the antennae of C. emarginatus that enter figs. The chemosensilla which are presumably involved in host discrimination, i.e., basiconic sensilla, multiporous placoid sensilla and basiconic capitate peg sensilla, are similar in shape and configuration, although they present some differences in abundance. These findings provide practical information on the adaptations of fig wasps and the relationship between multisensory antennae and functions in fig wasp behaviour.     

Fine structure of antennal sensilla of male Aedes aegypti (L.)

The terminal two antennal segments of male Aedes aegypti bear the same variety of sensillar types as the female's antenna, namely, sensilla chaetica, sensilla coeloconica, sensilla ampullacea, grooved pegs, and four types of sensilla trichodea: long and short, pointed-tipped trichodea and blunt-tipped types I and II. Each type of sensillum has a similar fine structure in both sexes. Of the 514 neurones which innervate these sensilla in the male, 91% are olfactory receptors, 7% mechanoreceptors, and 2% thermoreceptors. The total number of neurones in the male is about four times fewer than in the female, but the ratio of those responding to the various stimuli is similar.The sensilla studied herein probably mediate stimuli involved in location of suitable resting sites and nectar meals. In addition they are apparently involved in location of vertebrates as recent studies indicate that certain male mosquitoes are attracted to hosts to bring them into the proximity of the females for mating. This host finding behaviour of males would explain why they have the same sprectrum of sensillar types as do females.     

The harvestman tarsus and tarsal flexor system with notes on appendicular sensory structures in laniatores

The tarsal flexor system, a novel system of retinacular structures, is described for the first time based on morphological and ultrastructural examinations of several Neotropical harvestmen (Opiliones: Laniatores). The tarsal flexor system is made up of many individual pulleys that function to maintain close apposition between the tendon and internal ventral surface of the cuticle in the tarsus. Pulley cells are specialized tendinous cells that form the semi‐circular, retinacular pulley system in the tarsus; these cells contain parallel arrays of microtubules that attach to cuticular fibers extending from deep within the cuticle (i.e., tonofibrillae). The tarsal flexor system is hypothesized to provide mechanical advantage for tarsal flexion and other movements of the tarsus. This system is discussed with regards to other lineages of Opiliones, especially those that exhibit prehensility of the tarsus (i.e., Eupnoi). Comparing tarsal morphology of laniatorid harvestmen to other well‐studied arachnids, we review some literature that may indicate the presence of similar tarsal structures in several arachnid orders. The general internal organization of the tarsus is described, and ultrastructural data are presented for a number of tarsal structures, including sensilla chaetica and the tarsal perforated organ. Sensilla chaetica possess an internal lumen with dendritic processes in the center and exhibit micropores at the distal tip. With respect to the tarsal perforated organ, we found no ultrastructural evidence for a sensory or secretory function, and we argue that this structure is the result of a large pulley attachment site on the internal surface of the cuticle. A small, previously undocumented muscle located in the basitarsus is also reported. J. Morphol. 274:1216–1229, 2013. © 2013 Wiley Periodicals, Inc.     

德国小蠊触角感器的扫描电镜观察

用电子显微镜观察德国小蠊Blattella germanica(L.)雌成虫、雄成虫、老熟若虫和低龄若虫的触角,发现其上分布有大量感器,为刺形感器(Ⅰ、Ⅱ型)、锥形感器、毛形感器、弧形感器、帽形感器、边缘感器和椭圆感器。其中刺形感器(Ⅰ、Ⅱ型)、锥形感器、毛形感器、弧形感器和边缘感器在各种虫态均有分布,帽形感器仅见于成虫触角鞭节上。在各种不同虫态中,雌雄成虫含有所有种类的感器,老熟若虫触角亚节数最多,低龄若虫的各类感器的感毛长度和基部横径普遍较小。