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Showing 1 - 200 of 1720 Journals sorted alphabetically
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Journal Cover Arthropod Structure & Development
  [SJR: 0.983]   [H-I: 45]   [2 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1467-8039
   Published by Elsevier Homepage  [3177 journals]
  • Editorial
    • Authors: Alexander Steinbrecht; Nicholas Strausfeld; Gerhard Scholtz
      First page: 1
      Abstract: Publication date: January 2018
      Source:Arthropod Structure & Development, Volume 47, Issue 1
      Author(s): Alexander Steinbrecht, Nicholas Strausfeld, Gerhard Scholtz

      PubDate: 2018-02-15T06:25:10Z
      DOI: 10.1016/j.asd.2018.01.004
  • Diversity of symbiotic microbiota in Deltocephalinae leafhoppers (Insecta,
           Hemiptera, Cicadellidae)
    • Authors: Michał Kobiałka; Anna Michalik; Jacek Szwedo; Teresa Szklarzewicz
      Abstract: Publication date: Available online 13 April 2018
      Source:Arthropod Structure & Development
      Author(s): Michał Kobiałka, Anna Michalik, Jacek Szwedo, Teresa Szklarzewicz
      Symbiotic microorganisms associated with thirteen species of the subfamily Deltocephalinae were examined using microscopic and molecular techniques. Athysanus argentarius, Euscelis incisus, Doratura stylata, Arthaldeus pascuellus, Errastunus ocellaris, Jassargus flori, Jassargus pseudocellaris, Psammotettix alienus, Psammotettix confinis, Turrutus socialis and Verdanus abdominalis harbor two types of ancient bacteriome-associated microorganisms: bacteria Sulcia (phylum Bacteroidetes) and bacteria Nasuia (phylum Proteobacteria, class Betaproteobacteria). In Balclutha calamagrostis and Balclutha punctata, the bacterium Nasuia has not been detected. In the bacteriomes of both species of Balclutha examined, only bacteria Sulcia occur, whereas Sodalis-like symbionts (phylum Proteobacteria, class Gammaproteobacteria) are localized in the fat body cells, in close vicinity of the bacteriomes. To our knowledge, this is the first report of the co-existence in Deltocephalinae leafhoppers of the ancient symbiont Sulcia and the more recently acquired Sodalis-like bacterium. The obtained results provide further evidence indicating that Deltocephalinae leafhoppers are characterized by a large diversity of symbiotic systems, which results from symbiont acquisition and replacement. The obtained results are additionally discussed in phylogenetic context.
      Graphical abstract image

      PubDate: 2018-04-15T14:58:45Z
      DOI: 10.1016/j.asd.2018.03.005
  • Chonopeltis australis (Crustacea: Branchiura); the female reproductive
    • Authors: Lourelle Alicia Martins Neethling; Annemariè Avenant-Oldewage
      Abstract: Publication date: Available online 12 April 2018
      Source:Arthropod Structure & Development
      Author(s): Lourelle Alicia Martins Neethling, Annemariè Avenant-Oldewage
      The female reproductive system has been described for Dolops ranarum (Stuhlman, 1891) and various Argulus spp. but, there is no description of the reproductive system for Dipteropeltis spp. Calman, 1912 or Chonopeltis spp. Thiele, 1900. This paper describes the female reproductive system and egg laying behaviour of C honopeltis australis Boxshall, 1976 using histology, light microscopy, scanning electron microscopy and observations. The histological study of six specimens showed that the organ structure is similar to that of Argulus spp. and D. ranarum. The oocytes therefore develop in the gonocoel, are ovulated into the lumen of the ovary which is continuous with the functional oviduct and eventually the gonopore. Females of C. australis deposit eggs on the surrounding substrate while the fish is at rest, without leaving the host, thereby mitigating the risk of not locating a host again.

      PubDate: 2018-04-15T14:58:45Z
      DOI: 10.1016/j.asd.2018.03.004
  • Postembryonic development of pycnogonids: A deeper look inside
    • Authors: Nina Alexeeva; Yuta Tamberg; Natalia Shunatova
      Abstract: Publication date: Available online 21 March 2018
      Source:Arthropod Structure & Development
      Author(s): Nina Alexeeva, Yuta Tamberg, Natalia Shunatova
      Sea spiders form a small, enigmatic group of recent chelicerates, with an unusual bodyplan, oligosegmented larvae and a postembryonic development that is punctuated by many moults. To date, only a few papers examined the anatomical and ultrastructural modifications of the larvae and various instars. Here we traced both internal and external events of the whole postembryonic development in Nymphon brevirostre HODGE 1863 using histology, SEM, TEM and confocal microscopy. During postembryonic development, larvae of this species undergo massive reorganization: spinning apparatus and chelar glands disappear; larval legs redifferentiate; three new segments and the abdomen are formed with their corresponding internal organs and appendages; circulatory and reproductive systems develop anew and the digestive and the nervous systems change dramatically. The body cavity remains schizocoelic throughout development, and no traces of even transitory coeloms were found in any instar. In Nymphon brevirostre, just like in Artemia salina LINNAEUS 1758 the heart arises through differentiation of the already existing schizocoel, and thus the circulatory systems of arthropods and annelids are not homologous. We found that classical chelicerate tagmata, prosoma and opisthosoma, are inapplicable to adult pycnogonids, with the most striking difference being the fate and structure of the seventh appendage-bearing segment.
      Graphical abstract image

      PubDate: 2018-04-15T14:58:45Z
      DOI: 10.1016/j.asd.2018.03.002
  • Morphological and electrophysiological differences in tarsal chemosensilla
           between the wild silkmoth Bombyx mandarina and the domesticated species
           Bombyx mori
    • Authors: Hiroki Takai; Kiyoshi Asaoka; Fumiko Ishizuna; Takashi Kiuchi; Susumu Katsuma; Toru Shimada
      Abstract: Publication date: Available online 19 March 2018
      Source:Arthropod Structure & Development
      Author(s): Hiroki Takai, Kiyoshi Asaoka, Fumiko Ishizuna, Takashi Kiuchi, Susumu Katsuma, Toru Shimada
      Gustatory and olfactory senses of phytophagous insects play important roles in the recognition of host plants. In the domestic silkmoth Bombyx mori and its wild species Bombyx mandarina, the morphologies and responses of adult olfactory organs (antennae) have been intensely investigated. However, little is known about these features of adult gustatory organs and the influence of domestication on the gustatory sense. Here we revealed that both species have two types of sensilla (thick [T] and slim [S] types) on the fifth tarsomeres of the adult legs. In both species, females have 3.6–6.9 times more T-sensilla than males. Therefore, T-sensilla seem to play more important roles in females than in males. Moreover, gustatory cells of T-sensilla of B. mandarina females responded intensely to mulberry leaf extract in electrophysiological experiments, while T-sensilla of B. mori females (N4 strain) hardly responded to mulberry leaf extract. These results suggest that T-sensilla of B. mandarina females are involved in the recognition of oviposition sites. We also observed that, in three B. mori strains (N4, p50T, and Kinshu × Showa), the densities of sensilla on the fifth tarsomeres were much lower than in B. mandarina. These results indicate that domestication has influenced the tarsal gustatory system of B. mori.

      PubDate: 2018-04-15T14:58:45Z
      DOI: 10.1016/j.asd.2018.03.001
  • A first phylogenetic analysis of the pill millipedes of the order
           Glomerida, with a special assessment of mandible characters (Myriapoda,
           Diplopoda, Pentazonia)
    • Authors: Jan Philip Oeyen; Thomas Wesener
      Abstract: Publication date: Available online 9 March 2018
      Source:Arthropod Structure & Development
      Author(s): Jan Philip Oeyen, Thomas Wesener
      The pill millipedes of the order Glomerida are a moderately diverse group with a classical Holarctic distribution pattern. Their classification is based on a typological system utilizing mainly a single character complex, the male telopods. In order to infer the apomorphies of the Glomerida, to elucidate its position in the Pentazonia, and to test the monophyly of its families and subfamilies, we conduct the first phylogenetic analysis of the order. To provide additional characters, we comparatively analyze the mandible using scanning electron microscopy. The final character matrix consists of 69 characters (11 mandible characters) and incorporates 22 species from 20 of the 34 pill millipede genera, representing all families and subfamilies, except the monotypic Mauriesiinae. Two species from each of the two other Pentazonian orders Sphaerotheriida and Glomeridesmida, as well as two Spirobolida, are included as outgroup taxa. The Glomerida are recovered as monophyletic and are supported by five apomorphies. Within the Pentazonia, the Glomeridesmida are recovered as the sister group to the classical Oniscomorpha (Sphaerotheriida + Glomerida) with weak support. The analysis provides little resolution within the Glomerida, resulting in numerous polytomies. Further morphological characters and/or the addition of molecular analyses are needed to produce a robust phylogenetic classification of the Glomerida.

      PubDate: 2018-03-19T12:10:15Z
      DOI: 10.1016/j.asd.2018.02.005
  • Jumping mechanisms and performance in beetles. II. Weevils (Coleoptera:
           Curculionidae: Rhamphini)
    • Authors: Konstantin Nadein; Oliver Betz
      Abstract: Publication date: Available online 6 March 2018
      Source:Arthropod Structure & Development
      Author(s): Konstantin Nadein, Oliver Betz
      We describe the kinematics and performance of the natural jump in the weevil Orchestes fagi (Fabricius, 1801) (Coleoptera: Curculionidae) and its jumping apparatus with underlying anatomy and functional morphology. In weevils, jumping is performed by the hind legs and involves the extension of the hind tibia. The principal structural elements of the jumping apparatus are (1) the femoro-tibial joint, (2) the metafemoral extensor tendon, (3) the extensor ligament, (4) the flexor ligament, (5) the tibial flexor sclerite and (6) the extensor and flexor muscles. The kinematic parameters of the jump (from minimum to maximum) are 530–1965 m s−2 (acceleration), 0.7–2.0 m s−1 (velocity), 1.5–3.0 ms (time to take-off), 0.3–4.4 μJ (kinetic energy) and 54–200 (g-force). The specific joint power as calculated for the femoro-tibial joint during the jumping movement is 0.97 W g−1. The full extension of the hind tibia during the jump was reached within up to 1.8–2.5 ms. The kinematic parameters, the specific joint power and the time for the full extension of the hind tibia suggest that the jump is performed via a catapult mechanism with an input of elastic strain energy. A resilin-bearing elastic extensor ligament that connects the extensor tendon and the tibial base is considered to be the structure that accumulates the elastic strain energy for the jump. According to our functional model, the extensor ligament is loaded by the contraction of the extensor muscle, while the co-contraction of the antagonistic extensor and flexor muscles prevents the early extension of the tibia. This is attributable to the leverage factors of the femoro-tibial joint providing a mechanical advantage for the flexor muscles over the extensor muscles in the fully flexed position. The release of the accumulated energy is performed by the rapid relaxation of the flexor muscles resulting in the fast extension of the hind tibia propelling the body into air.

      PubDate: 2018-03-08T11:10:38Z
      DOI: 10.1016/j.asd.2018.02.006
  • Morphology of the elytral base sclerites
    • Authors: Miwa Sugimoto; Naoki Ogawa; Kazunori Yoshizawa
      Abstract: Publication date: Available online 22 February 2018
      Source:Arthropod Structure & Development
      Author(s): Miwa Sugimoto, Naoki Ogawa, Kazunori Yoshizawa
      The elytral base sclerites (= sclerites located at the articular region between the forewing and thorax in Coleoptera) of selected taxa were examined and homologized. Although the elytral base sclerites are highly modified compared to the wing base sclerites of the other neopterans, they can be homologized by using the conservative wing flapping and folding lines as landmarks. A reduction of the first axillary sclerite was identified as a general trend of the elytral base sclerites, although the sclerite usually has a very important function to mediate flight power from the notum to the wing. This result indicates that the functional constraint against the basal sclerites is relaxed because of the lack of an ability to produce flight power by elytra. In contrast, the elytral folding system formed by the basal sclerites is well retained, which probably occurs because proper wing folding is a key for the shelter function of the elytra. The elytral base sclerites apparently contain more homoplasies than the serially homologous hindwing base sclerites of Coleoptera, which suggests that the structure is less useful for higher-level systematics. However, the faster evolutionary rate of the elytral base sclerites suggests there is potential for studying the lower-level phylogeny of Coleoptera.

      PubDate: 2018-02-26T08:55:52Z
      DOI: 10.1016/j.asd.2018.02.004
  • Independent suboesophageal neuronal innervation of the defense gland and
           longitudinal muscles in the stick insect (Peruphasma schultei) prothorax
    • Authors: Konrad Stolz; Johannes Strauß; Joscha Arne Alt; Reinhard Lakes-Harlan
      Abstract: Publication date: Available online 17 February 2018
      Source:Arthropod Structure & Development
      Author(s): Konrad Stolz, Johannes Strauß, Joscha Arne Alt, Reinhard Lakes-Harlan
      This study investigates the neuroanatomy of the defense gland and a related muscle in the stick insect Peruphasma schultei with axonal tracing and histological sections. The gland is innervated by three neurons through the Nervus anterior of the suboesophageal ganglion (SOG), the ipsilateral neuron (ILN), the contralateral neuron (CLN) and the prothoracic intersegmental neuron (PIN). The ILN has a large soma which is typical for motoneurons that cause fast contraction of large muscles and its dendrites are located in motor-sensory and sensory neuropile areas of the SOG. The CLN might be involved in the coordination of bilateral or unilateral discharge as its neurites are closely associated to the ILN of the contralateral gland. Close to the ejaculatory duct of the gland lies a dorsal longitudinal neck muscle, musculus pronoto-occipitalis (Idlm2), which is likely indirectly involved in gland discharge by controlling neck movements and, therefore, the direction of discharge. This muscle is innervated by three ventral median neurons (VMN). Thus, three neuron types (ILN, CLN, and PIN) innervate the gland muscle directly, and the VMNs could aid secretion indirectly. The cytoanatomy of motorneurons innervating the defense gland and neck muscle are discussed regarding the structure and functions of the neuropile in the SOG. As a basis for the neuroanatomical study on the defense gland we assembled a map of the SOG in Phasmatodea.

      PubDate: 2018-02-26T08:55:52Z
      DOI: 10.1016/j.asd.2018.02.003
  • Ultrastructure and function of the seminal vesicle of Bittacidae (Insecta:
    • Authors: Qi-Hui Lyu; Bei-Bei Zhang; Bao-Zhen Hua
      Abstract: Publication date: Available online 15 February 2018
      Source:Arthropod Structure & Development
      Author(s): Qi-Hui Lyu, Bei-Bei Zhang, Bao-Zhen Hua
      The fine structure of the seminal vesicle and reproductive accessory glands was investigated in Bittacidae of Mecoptera using light and transmission electron microscopy. The male reproductive system of Bittacidae mainly consists of a pair of testes, a pair of vasa deferentia, and an ejaculatory sac. The vas deferens is greatly expanded for its middle and medio-posterior parts to form a well-developed seminal vesicle. The seminal vesicle is composed of layers of developed muscles and a mono-layered epithelium surrounding the small central lumen. The epithelium is rich in rough endoplasmic reticulum and mitochondria, and secretes vesicles and granules into the central lumen by merocrine mechanisms. A pair of elongate mesodermal accessory glands opens into the lateral side of the seminal vesicles. The accessory glands are similar to the seminal vesicle in structure, also consisting of layers of muscle fibres and a mono-layered elongated epithelium, the cells of which contain numerous cisterns of rough endoplasmic reticulum and mitochondria, and a few Golgi complexes. The epithelial cells of accessory glands extrude secretions via apocrine and merocrine processes. The seminal vesicles mainly serve the function of secretion rather than temporarily storing spermatozoa. The sperm instead are temporarily stored in the epididymis, the greatly coiled distal portion of the vas deferens.
      Graphical abstract image

      PubDate: 2018-02-15T06:25:10Z
      DOI: 10.1016/j.asd.2018.02.001
  • Development of calcium bodies in Hylonsicus riparius (Crustacea: Isopoda)
    • Authors: Miloš Vittori; Mohammed Khurshed; Daisy I. Picavet; Cornelis J.F. van Noorden; Jasna Štrus
      Abstract: Publication date: Available online 15 February 2018
      Source:Arthropod Structure & Development
      Author(s): Miloš Vittori, Mohammed Khurshed, Daisy I. Picavet, Cornelis J.F. van Noorden, Jasna Štrus
      Calcium bodies are internal epithelial sacs found in terrestrial isopods of the family Trichoniscidae that contain a mineralized extracellular matrix that is deposited and resorbed in relation to the molt cycle. Calcium bodies in several trichoniscids are filled with bacteria, the function of which is currently unknown. The woodlouse Hyloniscus riparius differs from other trichoniscids in that it possesses two different pairs of calcium bodies, the posterior pair being filled with bacteria and the anterior pair being devoid of bacteria. We explored the development of these organs and bacterial colonization of their lumen during the postmarsupial development with the use of optical clearing and whole-body confocal imaging of larval and juvenile stages. Our results show that calcium bodies are formed as invaginations of the epidermis in the region of intersegmental membranes during the postmarsupial development. The anterior pair of calcium bodies is generated during the first postmarsupial manca stage, whereas the posterior calcium bodies first appear in juveniles and are immediately colonized by bacteria, likely through a connection between the calcium body lumen and the body surface. Mineral is deposited in calcium bodies as soon as they are present.

      PubDate: 2018-02-15T06:25:10Z
      DOI: 10.1016/j.asd.2018.02.002
  • Book lung development in juveniles and adults of the cobweb spider,
           Parasteatoda tepidariorum C. L. Koch, 1841 (Araneomorphae, Theridiidae)
    • Authors: Roger D. Farley
      Abstract: Publication date: Available online 1 February 2018
      Source:Arthropod Structure & Development
      Author(s): Roger D. Farley
      Light and transmission electron microscopy were used to study the development of new book lung lamellae in juvenile and adult spiders (Parasteatoda tepidariorum). As hypothesized earlier in a study of embryos, mesenchyme cells dispersed throughout the opisthosoma (EMT) are a likely source of precursor epithelial cells (MET) for the new lamellae. The precursor cells in juveniles and adults continue many of the complex activities observed in embryos, e.g., migration, alignment, lumen formation, thinning, elongation, and secretion of the cuticle of air channel walls and trabeculae. The apicobasal polarity of precursor cells for new channels is apparently induced by the polarity pattern of precursor cells of channels produced earlier. Thus, new air and hemolymph channels extend and continue the alternating pattern of older channels. At sites more distant from the spiracle and atrium, new channels are usually produced by the mode II process (intracellular alignment and merging of vesicles). These air channels have bridging trabeculae and are quite stable in size throughout their length. At sites closer to the spiracle and atrium, new channels may be produced by mode I (coalescence of merocrine vesicle secretion). This raises the hypothesis that structural and functional differences in mode I and II channels and differing oxygen and fluid conditions with distance from the spiracle and atrium determine the mode of formation of new channels. Observations herein support an earlier hypothesis that there is some intercellular apical/apical and basal/basal affinity among the opposed surfaces of aligned precursor cells. This results in the alternating pattern of air channels at the apical and hemolymph channels at the basal cell surfaces.

      PubDate: 2018-02-15T06:25:10Z
      DOI: 10.1016/j.asd.2018.01.002
  • Micro-morphological adaptations of the wing nodus to flight behaviour in
    • Authors: H. Rajabi; K. Stamm; E. Appel; S.N. Gorb
      Abstract: Publication date: Available online 19 January 2018
      Source:Arthropod Structure & Development
      Author(s): H. Rajabi, K. Stamm, E. Appel, S.N. Gorb
      Adult dragonflies can be divided into two major groups, perchers and fliers, exhibiting notably different flight behaviour. Previous studies have yielded conflicting results regarding the link between the wing macro-morphology and flight style in these two groups. In this study, we present the first systematic investigation of the micro-morphological differences of wings of percher and flier dragonflies in four closely related species from the family Libellulidae. Our results suggest that the shape and material composition of wing microstructural components and, in particular, the nodus are adapted to facilitate the specific wing functioning in fliers and perchers. The findings further indicate a decreasing trend in the area proportion of the soft resilin-dominated cuticle in the nodus in the series of species from typical perchers to typical fliers. Such a reduction in the resilin proportion in the nodus of fliers is associated with an increase in the wing aspect ratio. The knot-shaped protrusion at the nodus of perchers, which becomes notably smaller in that of strong fliers, is likely to act as a mechanical stopper, avoiding large wing displacements. This study aims to develop a novel framework for future research on the relationship between wing morphology and flight behaviour in dragonflies.

      PubDate: 2018-02-15T06:25:10Z
      DOI: 10.1016/j.asd.2018.01.003
  • The sensory equipment of a spider – A morphological survey of different
           sensillum types in both sexes of Argiope bruennichi (Araneae, Araneidae)
    • Authors: Anne-Sarah Ganske; Gabriele Uhl
      Abstract: Publication date: Available online 19 January 2018
      Source:Arthropod Structure & Development
      Author(s): Anne-Sarah Ganske, Gabriele Uhl
      Spiders show a wide range of sensory capabilities as evidenced by behavioural observations. Accordingly, spiders possess diverse sensory structures like mechano-, hygro-, thermo- or chemoreceptive sensilla. As to chemoreceptive structures, only trichoid tip-pore sensilla were found so far that were tested for gustation. That spiders are also able to receive airborne signals is corroborated by numerous behavioural experiments but the responsible structures have not been determined yet. Here, we provide sensilla distribution maps of pedipalps and walking legs of both sexes of the wasp spider Argiope bruennichi whose biology and mating system is well explored. By means of scanning electron microscopy, we scrutinized whether there is in fact only one type of trichoid pore sensillum and if so, if there are deviations in the outer structure of the tip-pore sensilla depending on their position on the body. We also describe the external structure and distribution of slit sense organs, trichobothria and tarsal organs. Our study shows that all four sensillum types occur on pedipalps and walking legs of both sexes. As to chemosensory organs, only tip-pore sensilla were found, suggesting that this sensillum type is used for both gustation and olfaction. The highest numbers of tip-pore sensilla were observed on metatarsi and tarsi of the first two walking legs. Mechanosensitive slit sense organs occur as single slit sensilla in rows along all podomers or as lyriform organs next to the joints. The mechanosensitive trichobothria occur on the basal part of tibiae and metatarsi. Tarsal organs occur on the dorsal side of all tarsi and the male cymbium. The distribution maps of the sensilla are the starting point for further exploration of internal, morphological differences of the sensilla from different regions on the body. Cryptic anatomical differences might be linked to functional differences that can be explored in combination with electrophysiological analyses. Consequently, the maps will help to elucidate the sensory world of spiders.

      PubDate: 2018-02-15T06:25:10Z
      DOI: 10.1016/j.asd.2018.01.001
  • Drinking with a very long proboscis: Functional morphology of orchid bee
           mouthparts (Euglossini, Apidae, Hymenoptera)
    • Authors: Jellena V. Düster; Maria H. Gruber; Florian Karolyi; John D. Plant; Harald W. Krenn
      Abstract: Publication date: Available online 29 December 2017
      Source:Arthropod Structure & Development
      Author(s): Jellena V. Düster, Maria H. Gruber, Florian Karolyi, John D. Plant, Harald W. Krenn
      Neotropical orchid bees (Euglossini) possess the longest proboscides among bees. In this study, we compared the feeding behavior and functional morphology of mouthparts in two similarly large-sized species of Euglossa that differ greatly in proboscis length. Feeding observations and experiments conducted under semi-natural conditions were combined with micro-morphological examination using LM, SEM and micro CT techniques. The morphometric comparison showed that only the components of the mouthparts that form the food tube differ in length, while the proximal components, which are responsible for proboscis movements, are similar in size. This study represents the first documentation of lapping behaviour in Euglossini. We demonstrate that Euglossa bees use a lapping-sucking mode of feeding to take up small amounts of fluid, and a purely suctorial technique for larger fluid quantities. The mouthpart movements are largely similar to that in other long-tongued bees, except that the postmentum in Euglossa can be extended, greatly enhancing the protraction of the glossa. This results in a maximal functional length that is about 50% longer than the length of the food canal composing parts of the proboscis. The nectar uptake and the sensory equipment of the proboscis are discussed in context to flower probing.

      PubDate: 2018-01-05T07:18:52Z
      DOI: 10.1016/j.asd.2017.12.004
  • Comparison of sensory structures on the antenna of different species of
           Philopotamidae (Insecta: Trichoptera)
    • Authors: Stanislav I. Melnitsky; Vladimir D. Ivanov; Mikhail Yu Valuyskiy; Lydia V. Zueva; Marianna I. Zhukovskaya
      Abstract: Publication date: Available online 28 December 2017
      Source:Arthropod Structure & Development
      Author(s): Stanislav I. Melnitsky, Vladimir D. Ivanov, Mikhail Yu Valuyskiy, Lydia V. Zueva, Marianna I. Zhukovskaya
      Structure and distribution of sensilla were studied in sixteen species of the caddisfly family Philopotamidae. Their antennae bear numerous curved trichoid and pseudoplacoid sensilla and fewer coronal, styloconic and chaetoid sensilla on the flagellar segments. The most numerous pseudoplacoid sensilla have non-specific localization. The curved trichoid sensilla form clusters ventrally on each antennal segment. Sensilla belonging to coronal, styloconic and chaetoid types have specific positions. Long grooved trichoid sensilla are located nonspecifically in all the studied species. The average number of sensilla per segment decreases from the proximal to distal part of the flagellum. Scapus and pedicellum are devoid of most types of sensilla, however, they bear the Böhm bristles and long trichoid sensilla. A positive correlation between antenna dimensions and its cuticular structures is found.

      PubDate: 2018-01-05T07:18:52Z
      DOI: 10.1016/j.asd.2017.12.003
  • The eversible tentacle organs of Polyommatus caterpillars (Lepidoptera,
           Lycaenidae): Morphology, fine structure, sensory supply and functional
    • Authors: W. Gnatzy; M. Jatho; T. Kleinteich; S.N. Gorb; R. Hustert
      Pages: 788 - 804
      Abstract: Publication date: November 2017
      Source:Arthropod Structure & Development, Volume 46, Issue 6
      Author(s): W. Gnatzy, M. Jatho, T. Kleinteich, S.N. Gorb, R. Hustert
      In their late (3rd and 4th) larval stages, caterpillars of the myrmecophilous lycaenid (Lepidoptera) species Polyommatus coridon and Polyommatus icarus, possess on their 8th abdominal segment two eversible so called tentacle organs (TOs). Previous histological and behavioural results have proposed that the TOs may release a volatile substance that elicits “excited runs” in attendant ants. In our study we investigated for the first time the temporal in- and eversion pattern of TOs. Using nerve tracing, Micro-CT, light- and electron microscopy techniques we studied (i) the histology of the 8th abdominal segment, (ii) the fine structure of the cuticular and cellular apparatus of the TOs, (iii) the attachment sites of the retractor muscle of each TO and (iv) the fine structure of the long slender tentacle hairs which are exposed to the outside, when the TOs are everted and fold back into the TO-sac during inversion. Our data show that the tentacle hairs are typical insect mechanoreceptors, each innervated by a small bipolar sensory cell with a tubular body in the tip of the outer dendritic segment. The latter is enclosed by a cuticular sheath previously called the “internal cuticular duct” and misinterpreted in earlier studies as the space, where the tentacle hairs actively secrete fluids. However, we found no glandular structures nearby or in the wall of the TO-sac. Also we did not reveal any conspicuous signs of secretory activity in one of the enveloping cells belonging to a tentacle hair. Although highly unusual features for an insect mechanoreceptor are: (a) the hair-shaft lumen of tentacle hairs contains flocculent material as well small vesicles and (b) the thin cuticular wall of the hair-shaft and its spines possess few tiny pores. Our data do not support the assumption of previous studies that volatile substances are released via the tentacle organs during their interactions with ants which in turn are supposed to cause excited runs in ants.

      PubDate: 2017-12-01T11:12:23Z
      DOI: 10.1016/j.asd.2017.10.003
  • Egg-laying behavior and morphological and chemical characterization of egg
           surface and egg attachment glue of the digger wasp Ampulex compressa
           (Hymenoptera, Ampulicidae)
    • Authors: Werner Gnatzy; Walter Volknandt; Anja Dzwoneck
      Abstract: Publication date: Available online 21 December 2017
      Source:Arthropod Structure & Development
      Author(s): Werner Gnatzy, Walter Volknandt, Anja Dzwoneck
      For providing their offspring females of the digger wasp species Ampulex compressa hunt cockroaches, paralyze them and attach as a rule one egg to the coxa of one of the mid legs of their prey. We observed the egg-laying behavior and examined with light- and scanning microscopy (i) nearly mature eggs from ovaries of freshly dissected females and (ii) eggs immediately after their deposition on the coxae of their prey. The length of the white bean-shaped eggs varied between 2.2 and 3.0 mm, their diameter between 0.66 and 0.72 mm, and their weight between 345 and 832 μg. The surface of fresh, untreated eggs shows even at higher magnifications (>20.000×) a smooth appearance. However, after conventional fixation, dehydration with ethyl-alcohol and critical-point drying the egg-surface exhibited a little bit texture. The eggs are at two-third of their underside glued to the coxa of the prey. With the naked eye the glue appears as a compact mass. The eggs may be mechanically removed from the substrate (their attachment site); however, in doing so the viscous attachment glue appears in a more fibrous consistence. The polypeptide composition washed off the egg surface and the glue revealed no similarities, whereas the molecular mass of two polypeptides were similar between glue and the Dufour's gland contents.

      PubDate: 2017-12-24T05:17:56Z
      DOI: 10.1016/j.asd.2017.11.010
  • Paradorippe granulata – A crab with external fertilization and a novel
           type of sperm storage organ challenges prevalent ideas on the evolution of
           reproduction in Eubrachyura (Crustacea: Brachyura: Dorippidae)
    • Authors: Juliane Vehof; Gerhard Scholtz; Carola Becker
      Abstract: Publication date: Available online 19 December 2017
      Source:Arthropod Structure & Development
      Author(s): Juliane Vehof, Gerhard Scholtz, Carola Becker
      Two fundamentally different sperm storage organs occur in Brachyura. The probably paraphyletic podotremes show intersegmental spermathecae, which are distant from oviducts and coxal gonopores. Hence, fertilization is external. In contrast to this, the seminal receptacles of Eubrachyura are directly connected with the ovaries. Thus, at least initial fertilization is internal. This pattern has been interpreted as an apomorphy of Eubrachyura. To test this hypothesis, we studied the morphology of the reproductive organs of Paradorippe granulata, a representative of the putatively early diverging eubrachyuran lineage Dorippoidea. Applying histology, 3D-reconstructions and micro-computed-tomography we revealed a novel type of sperm storage organ. Female P . granulata lack the characteristic eubrachyuran seminal receptacle. Instead sperm is stored in four cuticle-lined bursae, two on each side of the paired oviducts. The elaborate bulbous male gonopod with several terminal processes is adapted to transferring sperm into the female twin bursae. Since oviducts and twin bursae are not directly connected, spermatozoa and oocytes mix when gametes pass through the sternal vulva. Thus, fertilization in P . granulata is external. Our finding of a eubrachyuran crab that lacks seminal receptacles and exhibits external fertilization calls prevailing concepts on the evolution of sperm storage in Eubrachyura into question.
      Graphical abstract image

      PubDate: 2017-12-24T05:17:56Z
      DOI: 10.1016/j.asd.2017.12.002
  • The morphology of mouthparts, wings and genitalia of Paleozoic insect
           families Protohymenidae and Scytohymenidae reveals new details and
           supposed function
    • Authors: Martina Pecharová; Jakub Prokop
      Abstract: Publication date: Available online 18 December 2017
      Source:Arthropod Structure & Development
      Author(s): Martina Pecharová, Jakub Prokop
      Megasecoptera is an extinct group of insects with specialized rostrum-like mouthparts, which is a synapomorphy shared with all members of the Late Paleozoic Palaeodictyopterida, and markedly slender wings that are unable to flex backwards. Here we describe the close up morphology of Protohymenidae and Scytohymenidae and uncover new aspects of the endoskeleton (tentorium) of the head, structure of the mouthparts with discernible proximal part of stylets controlled by muscles, surface of compound eyes that consist of a hexagonal pattern of large facets, structure and microstructures on the wings and reconstruct male and female external genitalia using ESEM and light stereomicroscopy. Furthermore, we describe Protohymen novokshonovi sp. n. based on an exceptionally well preserved fossil from the early Permian at Tshekarda in Russia, which shows crucial details, and the earliest species of Protohymenidae, Carbohymen testai gen. et sp. n. from a late Carboniferous siderite nodule at Mazon Creek in Illinois, USA. Our comparative study confirmed a set of structural and microstructural details on their wings, such as the composite anterior wing margin, development of an apical cell and the previously unknown external genitalia. Based on the results and comparison of homologous structures known primarily for extant relatives, such as mayflies and dragonflies, we outline for the first time the function of the mouthparts, in particular, the stylets, structure of the tentorium, vision provided by large hexagonal ommatidia and male copulatory structures bearing curved claspers for holding a female during copulation and penial lobes with seminal grooves.

      PubDate: 2017-12-24T05:17:56Z
      DOI: 10.1016/j.asd.2017.11.006
  • “Open access” growth histories in millipedes (Diplopoda)
    • Authors: Henrik Enghoff; Laura Mark Jensen; Elena V. Mikhaljova
      Abstract: Publication date: Available online 16 December 2017
      Source:Arthropod Structure & Development
      Author(s): Henrik Enghoff, Laura Mark Jensen, Elena V. Mikhaljova
      A unique pattern of missing defence glands on certain body rings is described for two species of the millipede family Mongoliulidae, order Julida: Ussuriiulus pilifer Golovatch, 1980, and Koiulus interruptus Enghoff et al., 2017. Based on the patterns of missing glands observed in recently collected samples of the two species, numbers of podous and apodous body rings in successive stadia of the postembryonic development can be inferred for each individual millipede, which in turn allows the reconstruction of pathways of anamorphosis in these species. The inferred numbers of body rings in developmental stadia are compared with actual numbers observed on additional samples, including the type series, of U. pilifer. The pattern of missing glands in the two mongoliulid species is compared with the pattern of missing glands typical of the entire millipede order Polydesmida.
      Graphical abstract image

      PubDate: 2017-12-24T05:17:56Z
      DOI: 10.1016/j.asd.2017.11.009
  • The gnathobasic spine microstructure of recent and Silurian chelicerates
           and the Cambrian artiopodan Sidneyia: Functional and evolutionary
    • Authors: Russell D.C. Bicknell; John R. Paterson; Jean-Bernard Caron; Christian B. Skovsted
      Abstract: Publication date: Available online 15 December 2017
      Source:Arthropod Structure & Development
      Author(s): Russell D.C. Bicknell, John R. Paterson, Jean-Bernard Caron, Christian B. Skovsted
      Gnathobasic spines are located on the protopodal segments of the appendages of various euarthropod taxa, notably chelicerates. Although they are used to crush shells and masticate soft food items, the microstructure of these spines are relatively poorly known in both extant and extinct forms. Here we compare the gnathobasic spine microstructures of the Silurian eurypterid Eurypterus tetragonophthalmus from Estonia and the Cambrian artiopodan Sidneyia inexpectans from Canada with those of the Recent xiphosuran chelicerate Limulus polyphemus to infer potential variations in functional morphology through time. The thickened fibrous exocuticle in L. polyphemus spine tips enables effective prey mastication and shell crushing, while also reducing pressure on nerve endings that fill the spine cavities. The spine cuticle of E. tetragonophthalmus has a laminate structure and lacks the fibrous layers seen in L. polyphemus spines, suggesting that E. tetragonophthalmus may not have been capable of crushing thick shells, but a durophagous habit cannot be precluded. Conversely, the cuticle of S. inexpectans spines has a similar fibrous microstructure to L. polyphemus, suggesting that S. inexpectans was a competent shell crusher. This conclusion is consistent with specimens showing preserved gut contents containing various shelly fragments. The shape and arrangement of the gnathobasic spines is similar for both L. polyphemus and S. inexpectans, with stouter spines in the posterior cephalothoracic or trunk appendages, respectively. This differentiation indicates that crushing occurs posteriorly, while the gnathobases on anterior appendages continue mastication and push food towards and into the mouth. The results of recent phylogenetic analyses that considered both modern and fossil euarthropod clades show that xiphosurans and eurypterids are united as crown-group euchelicerates, with S. inexpectans placed within more basal artiopodan clades. These relationships suggest that gnathobases with thickened fibrous exocuticle, if not homoplasious, may be plesiomorphic for chelicerates and deeper relatives within Arachnomorpha. This study shows that the gnathobasic spine microstructure best adapted for durophagy has remained remarkably constant since the Cambrian.

      PubDate: 2017-12-24T05:17:56Z
      DOI: 10.1016/j.asd.2017.12.001
  • The antennae of damselfly larvae
    • Authors: Silvana Piersanti; Manuela Rebora
      Abstract: Publication date: Available online 12 December 2017
      Source:Arthropod Structure & Development
      Author(s): Silvana Piersanti, Manuela Rebora
      The larval antennal sensilla of two Zygoptera species, Calopteryx haemorroidalis (Calopterygidae) and Ischnura elegans (Coenagrionidae) are investigated with SEM and TEM. These two species have different antennae (geniculate, setaceous) and live in different environments (lotic, lentic waters). Notwithstanding this, similarities in the kind and distribution of sensilla are outlined: in both species the majority of sensilla types is located on the apical portion of the antenna, namely a composed coeloconic sensillum (possible chemoreceptor), two other coeloconic sensilla (possible thermo-hygroreceptors) and an apical seta (direct contact mechanoreceptor). Other mechanoreceptors, such as filiform hairs sensitive to movements of the surrounding medium or bristles positioned to sense the movements of the flagellar segments, are present on the antenna. Similarities in the antennal sensilla types and distribution are observed also with other dragonfly species, such as Onychogomphus forcipatus and Libellula depressa. A peculiar structure with an internal organization similar to that of a gland is observed in the apical antenna of C. haemorroidalis and I. elegans and it is present also in O. forcipatus and L. depressa. The possible function of this structure is at the moment unknown but deserves further investigations owing to its widespread presence in Odonata larvae.
      Graphical abstract image

      PubDate: 2017-12-13T03:17:54Z
      DOI: 10.1016/j.asd.2017.11.008
  • A century and a half of research on the evolution of insect flight
    • Authors: David E. Alexander
      Abstract: Publication date: Available online 6 December 2017
      Source:Arthropod Structure & Development
      Author(s): David E. Alexander
      The gill and paranotal lobe theories of insect wing evolution were both proposed in the 1870s. For most of the 20th century, the paranotal lobe theory was more widely accepted, probably due to the fundamentally terrestrial tracheal respiratory system; in the 1970s, some researchers advocated for an elaborated gill (“pleural appendage”) theory. Lacking transition fossils, neither theory could be definitively rejected. Winged insects are abundant in the fossil record from the mid-Carboniferous, but insect fossils are vanishingly rare earlier, and all earlier fossils are from primitively wingless insects. The enigmatic, isolated mandibles of Rhyniognatha (early Devonian) hint that pterygotes may have been present much earlier, but the question remains open. In the late 20th century, researchers used models to study the interaction of body and protowing size on solar warming and gliding abilities, and stability and glide effectiveness of many tiny adjustable winglets versus a single, large pair of immobile winglets. Living stoneflies inspired the surface-skimming theory, which provides a mechanism to bridge between aquatic gills and flapping wings. The serendipitously discovered phenomenon of directed aerial descent suggests a likely route to the early origin of insect flight. It provides a biomechanically feasible sequence from guided falls to fully-powered flight.
      Graphical abstract image

      PubDate: 2017-12-12T03:12:02Z
      DOI: 10.1016/j.asd.2017.11.007
  • Head shape variation in cerambycid saproxylic beetles as a function of
           host plant selection
    • Authors: Sandra M. Ospina-Garcés; José Alfredo Hernández-Cardenas; Víctor H. Toledo-Hernández; Angélica M. Corona-López; Alejandro Flores-Palacios
      Abstract: Publication date: Available online 1 December 2017
      Source:Arthropod Structure & Development
      Author(s): Sandra M. Ospina-Garcés, José Alfredo Hernández-Cardenas, Víctor H. Toledo-Hernández, Angélica M. Corona-López, Alejandro Flores-Palacios
      Saproxylic insects depend on deadwood for larval development, and a certain degree of specialization may be involved in their choice of host plants and/or wood in a particular stage of degradation. The plant species chosen for oviposition in turn act as an environmental pressure on the head morphology of larvae and it is expected that head shape plasticity varies directly with the number of woody plant species used for larval development in each insect species. We analyzed head shape variation in saproxylic beetles with respect to host plant species, maximum time of larval emergence and season of the year when insects colonized branches. Generalist species in the use of host plants showed significant variation in head shape and size. Time of emergence and season did not appear to affect head shape, although season was a determinant factor of abundance and possibly head size variation.

      PubDate: 2017-12-12T03:12:02Z
      DOI: 10.1016/j.asd.2017.11.005
  • Corrigendum to “Timing of autophagy and apoptosis during posterior silk
           gland degeneration in Bombyx mori” [Arthropod Struct. Dev. 46 (4) (2017)
    • Authors: Aurora Montali; Davide Romanelli; Silvia Cappellozza; Annalisa Grimaldi; Magda de Eguileor; Gianluca Tettamanti
      Abstract: Publication date: Available online 28 November 2017
      Source:Arthropod Structure & Development
      Author(s): Aurora Montali, Davide Romanelli, Silvia Cappellozza, Annalisa Grimaldi, Magda de Eguileor, Gianluca Tettamanti

      PubDate: 2017-12-01T11:12:23Z
      DOI: 10.1016/j.asd.2017.11.004
  • Egg structure and outline of embryonic development of the basal mantodean,
           Metallyticus splendidus Westwood, 1835 (Insecta, Mantodea, Metallyticidae)
    • Authors: Makiko Fukui; Mari Fujita; Shigekazu Tomizuka; Yuta Mashimo; Shota Shimizu; Chow-Yang Lee; Yasunori Murakami; Ryuichiro Machida
      Abstract: Publication date: Available online 26 November 2017
      Source:Arthropod Structure & Development
      Author(s): Makiko Fukui, Mari Fujita, Shigekazu Tomizuka, Yuta Mashimo, Shota Shimizu, Chow-Yang Lee, Yasunori Murakami, Ryuichiro Machida
      The egg structure and outline of the embryonic development of Metallyticus splendidus of one of the basal Mantodea representatives, Metallyticidae, were described in the present study. The results obtained were compared with those from the previous studies, to reconstruct and discuss the groundplan of Mantodea and Dictyoptera. In M. splendidus, the egg is spheroidal, it has a convex ventral side at the center in which numerous micropyles are grouped, and it possesses a conspicuous hatching line in its anterior half. These are the groundplan features of mantodean eggs and the “grouped micropyles in the ventral side of the egg” are regarded as an apomorphic groundplan feature of Dictyoptera. A small circular embryo is formed by a simple concentration of blastoderm cells, which then undergoes embryogenesis of the typical short germ band type. Blastokinesis is of the “non-reversion type” and the embryo keeps its original superficial position and original orientation throughout embryonic development. During the middle stages of development, the embryo undergoes rotation around the egg's anteroposterior axis. These features are a part of the groundplan of Mantodea. It is uncertain whether sharing of the “non-reversion type” of blastokinesis by Mantodea and blaberoidean Blattodea can be regarded as homology or homoplasy.

      PubDate: 2017-12-01T11:12:23Z
      DOI: 10.1016/j.asd.2017.11.001
  • Larval development of the symbiotic pea crab Pinnaxodes chilensis
           (H. Milne Edwards, 1837) (Decapoda, Brachyura, Pinnotheridae) reared in
    • Authors: M.E. Gonzalez-Canales; E. Marco-Herrero; M. Andreu-Cazenave; J.I. González-Gordillo
      Abstract: Publication date: Available online 20 November 2017
      Source:Arthropod Structure & Development
      Author(s): M.E. Gonzalez-Canales, E. Marco-Herrero, M. Andreu-Cazenave, J.I. González-Gordillo
      The complete larval development of Pinnaxodes chilensis (including four zoeal stages and a megalopa stage) is described and illustrated in detail for the first time. The descriptions are based on laboratory-reared larvae obtained from ovigerous females found inside specimens of the sea urchin Loxechinus albus collected in the coast of Valparaíso, Chile. In order to allow the correct differentiation of specimens from plankton samples, the larval stages of P. chilensis are compared with those from other Pinnotheridae species, whose larval development is known for the Chilean continental waters (Calyptraeotheres politus). The morphological characters described for P. chilensis larvae, as well as the comparison with the remaining larval development descriptions available for the genus Pinnaxodes, are used to discuss the heterogeneity within this genus.

      PubDate: 2017-12-01T11:12:23Z
      DOI: 10.1016/j.asd.2017.11.003
  • Advisory board/short GFA
    • Abstract: Publication date: November 2017
      Source:Arthropod Structure & Development, Volume 46, Issue 6

      PubDate: 2017-12-01T11:12:23Z
  • Yeast-like microorganisms in the scale insect Kermes quercus (Insecta,
           Hemiptera, Coccomorpha: Kermesidae). Newly acquired symbionts'
    • Authors: Elżbieta Podsiadło; Katarzyna Michalik; Anna Michalik; Teresa Szklarzewicz
      Abstract: Publication date: Available online 14 November 2017
      Source:Arthropod Structure & Development
      Author(s): Elżbieta Podsiadło, Katarzyna Michalik, Anna Michalik, Teresa Szklarzewicz
      Scale insects, like other plant sap-consumers, are host to symbiotic microorganisms which provide them with the substances missing from their diet. In contrast to most scale insects, Kermes quercus (Linnaeus) was regarded as asymbiotic. Our histological and ultrastructural observations show that in the body of the feeding stages of K. quercus collected in two locations (Warsaw and Cracow), numerous yeast-like microorganisms occur. These microorganisms were localized in the cytoplasm of fat body cells. The yeast-like microorganisms were observed neither in other organs of the host insect nor in the eggs. These microorganisms did not cause any damage to the structure of the ovaries and the course of oogenesis of the host insect. The females infected by them produced about 1300 larvae. The lack of these microorganisms in the cytoplasm of eggs indicates that they are not transmitted transovarially from mother to offspring. Molecular analyses indicated that the microorganisms which reside in the body of K. quercus are closely related to the entomopathogenic fungi Cordyceps and Ophiocordyceps, which belong to the Sordariomycetes class within the Ascomycota. The role of yeast-like microorganisms to their host insects remains unknown; however, it has been suggested that they may represent newly acquired symbionts.
      Graphical abstract image

      PubDate: 2017-11-18T12:51:52Z
      DOI: 10.1016/j.asd.2017.11.002
  • Evidence of a procentriole during spermiogenesis in the coccinellid insect
           Adalia decempunctata (L): An ultrastructural study
    • Authors: Romano Dallai; David Mercati; José Lino-Neto; Glenda Dias; Pietro Lupetti
      Abstract: Publication date: Available online 6 November 2017
      Source:Arthropod Structure & Development
      Author(s): Romano Dallai, David Mercati, José Lino-Neto, Glenda Dias, Pietro Lupetti
      We studied spermatogenesis and spermiogenesis in A dalia decempunctata (L), a beetle of the Coccinellidae family. The spermatocyte exhibits two centrioles which elongate to form a pair of primary cilia. A novel structure, appearing in cross sections as a dense droplet, is observed near the long centriole during spermiogenesis, and is soon accompanied by a procentriole (PCL). PCL structure consists of singlet microtubules, a central tubule and an incomplete cartwheel. The PCL persists until the end of spermiogenesis, when it vanishes together with the dense droplet. The sperm has an exceptionally long basal body and the nucleus is disposed parallel to the flagellar components, a peculiar trait shared by other species of the coccinellid group. The presence of a procentriole suggested by the use of antibodies is discussed.

      PubDate: 2017-11-11T12:05:56Z
      DOI: 10.1016/j.asd.2017.10.004
  • Scorpions pectines – Idiosyncratic chemo- and mechanosensory organs
    • Authors: Harald Wolf
      Abstract: Publication date: Available online 27 October 2017
      Source:Arthropod Structure & Development
      Author(s): Harald Wolf
      Scorpions possess specialised chemosensory appendages, the pectines. These comb-shaped limbs are located ventrally behind the walking legs. Like the antennae of mandibulate arthropods, they also serve a mechanosensory function. However, more than 90% of the sometimes well above 100,000 sensory neurons projecting from a pectine to the central nervous system are chemosensory. There are two primary projection neuropils. The posterior one, immediately adjacent to the pectine nerve entrance, has an intriguing substructure reminiscent of the olfactory glomeruli observed in the primary chemosensory neuropils of many arthropods and indeed of most bilaterian animals. There are further similarities, particularly to the antennal lobes of mandibulate arthropods, including dense innervation by a relatively small number of putative serotonergic interneurons and the presence of GABA immunoreactivity, indicative of inhibitory interactions. Scorpion idiosyncrasies include the flattened shape and broad size range of the glomerulus-like neuropil compartments. Further, these compartments are often not clearly delimited and form layers in the neuropil that are arranged like onion peels. In summary, the pectine appendages of scorpions and their central nervous projections appear as promising study subjects, particularly regarding comparative examination of chemosensory representation and processing strategies. The possibility of combined, rather than discrete, representations of chemo- and mechanosensory inputs should merit further study.

      PubDate: 2017-11-05T11:07:05Z
      DOI: 10.1016/j.asd.2017.10.002
  • Morpho-functional variety of the coxal glands in cheyletoid mites
           (Prostigmata). II. Cheyletidae
    • Authors: S.A. Filimonova
      Abstract: Publication date: Available online 23 October 2017
      Source:Arthropod Structure & Development
      Author(s): S.A. Filimonova
      Trombidiform mites are characterized by the presence of several paired glands in the anterior body portion united by a common conducting duct (podocephalic canal). Apart from the acinous (salivary) glands the podocephalic system includes a pair of tubular coxal glands (CGs) responsible for osmoregulation. The aim of the present study was to figure out how functional changes of acinous glands reflect on the corresponding CG. For this purpose, the anatomy and fine structure of the CG were analyzed in two mite species, Bakericheyla chanayi and Ornithocheyletia sp. (Cheyletidae), which have a different composition of their single acinous gland. The results showed that in both species the CG lacks a filtering saccule. It is composed of the proximal and distal tubes and leads into a cuticle-lined excretory duct. Both tubes demonstrate a similar species-specific fine structure. They are characterized by an extensive system of apical membrane invaginations (internal canals) associated with numerous large mitochondria. Local areas of modified internal canals were regularly observed in both species. They contain structures resembling those constituting filtering slit diaphragms of other animals. In O. sp., CG cells in addition demonstrate features characteristic of protein-like secretion. Apparently this correlates with the loss of true salivary glands in this species, as its acinous gland was previously assumed as silk producing. Contrary to this, the CG of B. chanayi shows no kind of granulation, which coincides with the presence of a salivary portion in its complex acinous gland. The microtubule-rich intercalary cells at the base of the excretory duct were associated with special muscles presumably regulating the dilation of the duct lumen. These cells might represent a basic feature common to different types of podocephalic glands.

      PubDate: 2017-11-05T11:07:05Z
      DOI: 10.1016/j.asd.2017.10.001
  • The pregenital abdomen of Enicocephalomorpha and morphological evidence
           for different modes of communication at the dawn of heteropteran evolution
    • Authors: Leonidas-Romanos Davranoglou; Petr Baňař; Christian M. Schlepütz; Beth Mortimer; Graham K. Taylor
      Abstract: Publication date: Available online 21 September 2017
      Source:Arthropod Structure & Development
      Author(s): Leonidas-Romanos Davranoglou, Petr Baňař, Christian M. Schlepütz, Beth Mortimer, Graham K. Taylor
      The internal and external anatomy of the posterior metathoracic region, pregenital abdomen, and associated nervous system of the heteropteran infraorder Enicocephalomorpha are thoroughly described, using an array of state-of-the art techniques. Based on morphology, it is hypothesised which modes of communication these insects use. This study is based primarily on an undescribed species of Cocles Bergroth, 1905 (Enicocephalidae) and another undescribed species of Lomagostus Villiers, 1958 (Aenictopecheidae), but additional representatives of the infraorder are also examined. Our results are compared with the literature on other Heteroptera. The metathoracic scent gland system of Enicocephalomorpha uses the same muscles as that of more derived Heteroptera, although the efferent system is different. The presence of a tergal plate and well-developed longitudinal musculature in the families Enicocephalidae and Aenictopecheidae, as well as a sexually dimorphic set of sclerites and membranes that allow an as yet undetermined type of motion, may indicate the presence of vibrational signaling in the infraorder, although experimental confirmation is required. Our findings raise new research questions regarding heteropteran functional morphology and communication.

      PubDate: 2017-09-23T10:28:26Z
      DOI: 10.1016/j.asd.2017.08.006
  • The scolopidial accessory organs and Nebenorgans in orthopteroid insects:
           Comparative neuroanatomy, mechanosensory function, and evolutionary origin
    • Authors: Johannes
      Abstract: Publication date: Available online 19 September 2017
      Source:Arthropod Structure & Development
      Author(s): Johannes Strauß
      Scolopidial sensilla in insects often form large sensory organs involved in proprioception or exteroception. Here the knowledge on Nebenorgans and accessory organs, two organs consisting of scolopidial sensory cells, is summarised. These organs are present in some insects which are model organisms for the physiology of mechanosensory systems (cockroaches and tettigoniids). Recent comparative studies documented the accessory organ in several taxa of Orthoptera (including tettigoniids, cave crickets, Jerusalem crickets) and the Nebenorgan in related insects (Mantophasmatodea). The accessory organ or Nebenorgan is usually a small organ of 8–15 sensilla located in the posterior leg tibia of all leg pairs. The physiological properties of the accessory organs and Nebenorgans are so far largely unknown. Taking together neuroanatomical and electrophysiological data from disparate taxa, there is considerable evidence that the accessory organ and Nebenorgan are vibrosensitive. They thus complement the larger vibrosensitive subgenual organ in the tibia. This review summarises the comparative studies of these sensory organs, in particular the arguments and criteria for the homology of the accessory organ and Nebenorgan among orthopteroid insects. Different scenarios of repeated evolutionary origins or losses of these sensory organs are discussed. Neuroanatomy allows to distinguish individual sensory organs for analysis of sensory physiology, and to infer scenarios of sensory evolution.

      PubDate: 2017-09-23T10:28:26Z
  • Advisory board/short GFA
    • Abstract: Publication date: September 2017
      Source:Arthropod Structure & Development, Volume 46, Issue 5

      PubDate: 2017-09-23T10:28:26Z
  • The allometry of the central nervous system during the postembryonic
           development of the spider Eratigena atrica
    • Authors: Teresa Napiórkowska; Jarosław Kobak
      Abstract: Publication date: Available online 9 September 2017
      Source:Arthropod Structure & Development
      Author(s): Teresa Napiórkowska, Jarosław Kobak
      During ontogenesis, the size of a spider body, tissues and organs increases dramatically. The aim of the study was to estimate changes in the central nervous system of postembryonic stages of Eratigena atrica and compare them with the literature data on species differing in behavioural traits. Allometric analysis involved evaluation of histological slides embedded in paraffin and stained with hematoxylin and eosin. The reduced major axis regression (RMA) was applied to find allometric relationships between the volumes of the particular parts of the body. All the measured parts of the central nervous system (CNS) were negatively allometrically related to the volume of the prosoma, showing that the increment of the CNS was lower than that of the entire body. The growth of the brain was negatively allometrically related to the growth of the CNS but the increment of the subesophageal ganglion was greater than that of the CNS, exhibiting a positive allometry. Within both these structures, the increase in neuropil volume was greater than the growth of the cortex (cell body rind). Thus, in postembryonic development, the share of the subesophageal ganglion and neuropil in the total volume of the CNS increased, whereas that of the brain and cortex decreased. The mode of the CNS development in E. atrica is similar to that observed in other arthropods, including Argiope aurantia, a spider of different ecology and behaviour.

      PubDate: 2017-09-11T19:43:44Z
      DOI: 10.1016/j.asd.2017.08.005
  • Asymmetric larval head and mandibles of Hydrophilus acuminatus (Insecta:
           Coleoptera, Hydrophilidae): Fine structure and embryonic development
    • Authors: Shun'ichi Sato; Toshio Inoda; Shuhei Niitsu; Souichirou Kubota; Yuji Goto; Yukimasa Kobayashi
      Abstract: Publication date: Available online 9 September 2017
      Source:Arthropod Structure & Development
      Author(s): Shun'ichi Sato, Toshio Inoda, Shuhei Niitsu, Souichirou Kubota, Yuji Goto, Yukimasa Kobayashi
      The larvae of a water scavenger beetle, Hydrophilus acuminatus, have strongly asymmetric mandibles; the right one is long and slender, whereas the left one is short and stout. The fine structure and embryonic development of the head capsule and mandibles of this species were examined using light and scanning electron microscopy, and asymmetries in shape were detected in these structures applying an elliptic Fourier analysis. The larval mandibles are asymmetric in the following aspects: whole length, the number, structure and arrangement of retinacula (inner teeth), and size and shape of both the molar and incisor regions. The larval head is also asymmetric; the left half of the head capsule is larger than the right, and the left adductor muscle of the mandible is much thicker than the right. The origin and developmental process of asymmetric mandibles were traced in developing embryos whose developmental period is about 270 h and divided into 10 stages. Mandibular asymmetries are produced by the cumulative effects of six stepwise modifications that occur from about 36% of the total developmental time onward. The significance of these modifications was discussed with respect to the functional advantages of asymmetries and the phylogeny of members of the Hydrophilidae.

      PubDate: 2017-09-11T19:43:44Z
      DOI: 10.1016/j.asd.2017.08.003
  • From insects to robots
    • Authors: Barbara Webb
      Abstract: Publication date: Available online 1 September 2017
      Source:Arthropod Structure & Development
      Author(s): Barbara Webb

      PubDate: 2017-09-05T19:06:55Z
      DOI: 10.1016/j.asd.2017.08.002
  • A lightweight, inexpensive robotic system for insect vision
    • Authors: Chelsea Sabo; Robert Chisholm; Adam Petterson; Alex Cope
      Abstract: Publication date: Available online 1 September 2017
      Source:Arthropod Structure & Development
      Author(s): Chelsea Sabo, Robert Chisholm, Adam Petterson, Alex Cope
      Designing hardware for miniaturized robotics which mimics the capabilities of flying insects is of interest, because they share similar constraints (i.e. small size, low weight, and low energy consumption). Research in this area aims to enable robots with similarly efficient flight and cognitive abilities. Visual processing is important to flying insects' impressive flight capabilities, but currently, embodiment of insect-like visual systems is limited by the hardware systems available. Suitable hardware is either prohibitively expensive, difficult to reproduce, cannot accurately simulate insect vision characteristics, and/or is too heavy for small robotic platforms. These limitations hamper the development of platforms for embodiment which in turn hampers the progress on understanding of how biological systems fundamentally work. To address this gap, this paper proposes an inexpensive, lightweight robotic system for modelling insect vision. The system is mounted and tested on a robotic platform for mobile applications, and then the camera and insect vision models are evaluated. We analyse the potential of the system for use in embodiment of higher-level visual processes (i.e. motion detection) and also for development of navigation based on vision for robotics in general. Optic flow from sample camera data is calculated and compared to a perfect, simulated bee world showing an excellent resemblance.

      PubDate: 2017-09-05T19:06:55Z
      DOI: 10.1016/j.asd.2017.08.001
  • Vision for navigation: What can we learn from ants'
    • Authors: Paul Graham; Andrew Philippides
      Abstract: Publication date: Available online 2 August 2017
      Source:Arthropod Structure & Development
      Author(s): Paul Graham, Andrew Philippides
      The visual systems of all animals are used to provide information that can guide behaviour. In some cases insects demonstrate particularly impressive visually-guided behaviour and then we might reasonably ask how the low-resolution vision and limited neural resources of insects are tuned to particular behavioural strategies. Such questions are of interest to both biologists and to engineers seeking to emulate insect-level performance with lightweight hardware. One behaviour that insects share with many animals is the use of learnt visual information for navigation. Desert ants, in particular, are expert visual navigators. Across their foraging life, ants can learn long idiosyncratic foraging routes. What's more, these routes are learnt quickly and the visual cues that define them can be implemented for guidance independently of other social or personal information. Here we review the style of visual navigation in solitary foraging ants and consider the physiological mechanisms that underpin it. Our perspective is to consider that robust navigation comes from the optimal interaction between behavioural strategy, visual mechanisms and neural hardware. We consider each of these in turn, highlighting the value of ant-like mechanisms in biomimetic endeavours.

      PubDate: 2017-08-06T05:58:00Z
      DOI: 10.1016/j.asd.2017.07.001
  • Jumping and the aerial behavior of aquatic mayfly larvae (Myobaetis
           ellenae, Baetidae)
    • Authors: Stephen P. Yanoviak; Robert Dudley
      Abstract: Publication date: Available online 13 July 2017
      Source:Arthropod Structure & Development
      Author(s): Stephen P. Yanoviak, Robert Dudley
      Mayfly larvae generally are aquatic, but some madicolous taxa (i.e., living in thin water films) crawl over rocks within streams and waterfalls. When startled, these larvae can break the water film, jump, and enter an aerial phase of locomotion. Because mayfly larvae have been suggested as potential exemplars for the origin of insect wings as tracheal gills, and furthermore represent the most basal extant lineage of pterygotes, we analyzed jumping behavior and free-fall trajectories for one such species of mayfly (Myobaetis ellenae, Baetidae) in Costa Rica. Jumping was commonplace in this taxon, but was undirected and was characterized by body spinning at high angular velocities. No aerodynamic role for the tracheal gills was evident. By contrast, jumping by a sympatric species of bristletail (Meinertellus sp., Archaeognatha) consistently resulted in head-first and stable body postures during aerial translation. Although capable of intermittently jumping into the air, the mayfly larvae could neither control nor target their aerial behavior. By contrast, a stable body posture during jumps in adult bristletails, together with the demonstrated capacity for directed aerial descent in arboreal representatives of this order, support ancestrally terrestrial origins for insect flight within the behavioral context of either jumping or falling from heights.

      PubDate: 2017-07-22T04:01:09Z
      DOI: 10.1016/j.asd.2017.06.005
  • Optic flow-based collision-free strategies: From insects to robots
    • Authors: Julien R. Serres; Franck Ruffier
      Abstract: Publication date: Available online 11 July 2017
      Source:Arthropod Structure & Development
      Author(s): Julien R. Serres, Franck Ruffier
      Flying insects are able to fly smartly in an unpredictable environment. It has been found that flying insects have smart neurons inside their tiny brains that are sensitive to visual motion also called optic flow. Consequently, flying insects rely mainly on visual motion during their flight maneuvers such as: takeoff or landing, terrain following, tunnel crossing, lateral and frontal obstacle avoidance, and adjusting flight speed in a cluttered environment. Optic flow can be defined as the vector field of the apparent motion of objects, surfaces, and edges in a visual scene generated by the relative motion between an observer (an eye or a camera) and the scene. Translational optic flow is particularly interesting for short-range navigation because it depends on the ratio between (i) the relative linear speed of the visual scene with respect to the observer and (ii) the distance of the observer from obstacles in the surrounding environment without any direct measurement of either speed or distance. In flying insects, roll stabilization reflex and yaw saccades attenuate any rotation at the eye level in roll and yaw respectively (i.e. to cancel any rotational optic flow) in order to ensure pure translational optic flow between two successive saccades. Our survey focuses on feedback-loops which use the translational optic flow that insects employ for collision-free navigation. Optic flow is likely, over the next decade to be one of the most important visual cues that can explain flying insects' behaviors for short-range navigation maneuvers in complex tunnels. Conversely, the biorobotic approach can therefore help to develop innovative flight control systems for flying robots with the aim of mimicking flying insects’ abilities and better understanding their flight.

      PubDate: 2017-07-22T04:01:09Z
      DOI: 10.1016/j.asd.2017.06.003
  • Functional morphology of comminuting feeding structures of Trichodactylus
           borellianus (Brachyura, Decapoda, Trichodactylidae), an omnivorous
           freshwater crab
    • Authors: Débora de Azevedo Carvalho; Maria Florencia Viozzi; Pablo Agustín Collins; Verónica Williner
      Abstract: Publication date: Available online 28 June 2017
      Source:Arthropod Structure & Development
      Author(s): Débora de Azevedo Carvalho, Maria Florencia Viozzi, Pablo Agustín Collins, Verónica Williner
      Crustaceans exhibit great diversity of feeding structures with morphological traits that are useful to infer the general trophic habits of species. In this study, we analyzed the functional morphology of comminuting feeding structures (mandibles, chelipeds, gastric mill) of the freshwater crab Trichodactylus borellianus directly related with the food fragmentation. The heterochely and mechanical advantage (MA) of the chelae were also studied. In both analyses, we considered the relationship between morphology and the natural diet. We expected to find a consistent relation between feeding habits and morphological traits. In general, we found simple structures armed with uniform setal systems and feeding appendages without pronounced teeth or spines. Mandibles have primarily cutting functions, helping with the food anchoring and fragmentation with mandibular palps armed with pappose setae. Chelipeds were covered with spines and simple setae. Adult males exhibited right-handedness with high MA of the major chelae. The ingested, relatively large pieces of food are finally chewed by a gastric mill equipped with sharp cusps characteristic of decapods with low ingestion of crude fiber material. The morphology of the feeding apparatus revealed that it is well adapted to an omnivorous diet, being able to cope with dietary changes.

      PubDate: 2017-07-01T20:42:33Z
      DOI: 10.1016/j.asd.2017.05.001
  • The thoracic morphology of the wingless dune cricket Comicus calcaris
           (Orthoptera: Schizodactylidae): Novel apomorphic characters for the group
           and adaptations to sand desert environments
    • Authors: Fanny Leubner; Sven Bradler; Benjamin Wipfler
      Abstract: Publication date: Available online 21 April 2017
      Source:Arthropod Structure & Development
      Author(s): Fanny Leubner, Sven Bradler, Benjamin Wipfler
      Schizodactylidae, splay-footed or dune crickets, represents a distinct lineage among the highly diverse orthopteran subgroup Ensifera (crickets, katydids and allies). Only two extant genera belong to the Schizodactylidae: the winged Eurasian genus Schizodactylus, whose ecology and morphology is well documented, and the wingless South African Comicus, for which hardly any studies providing morphological descriptions have been conducted since its taxonomic description in 1888. Based on the first in-depth study of the skeletomuscular system of the thorax of Comicus calcaris Irish 1986, we provide information on some unique characteristics of this character complex in Schizodactylidae. They include a rigid connection of prospinasternite and mesosternum, a T-shaped mesospina, and a fused meso- and metasternum. Although Schizodactylidae is mainly characterized by group-specific anatomical traits of the thorax, its bifurcated profuca supports a closer relationship to the tettigonioid ensiferans, like katydids, wetas, and hump-winged crickets. Some specific features of the thoracic musculature of Comicus seem to be correlated to the skeletal morphology, e.g., due to the rigid connection of the tergites and pleurites in the pterothorax not a single direct flight muscle is developed. We show that many of the thoracic adaptations in these insects are directly related to their psammophilous way of life. These include a characteristic setation of thoracic sclerites that prevent sand grains from intrusion into vulnerable membranous areas, the striking decrease in size of the thoracic spiracles that reduces the respirational water loss, and a general trend towards a fusion of sclerites in the thorax.
      Graphical abstract image

      PubDate: 2017-04-26T15:28:16Z
      DOI: 10.1016/j.asd.2017.03.006
  • Comparative morphology of the prothoracic leg in heliconian butterflies:
           Tracing size allometry, podite fusions and losses in ontogeny and
    • Authors: Gilson R.P. Moreira; Denis S. Silva; Gislene L. Gonçalves
      Abstract: Publication date: Available online 20 April 2017
      Source:Arthropod Structure & Development
      Author(s): Gilson R.P. Moreira, Denis S. Silva, Gislene L. Gonçalves
      Prothoracic legs of heliconian butterflies (Nymphalidae, Heliconiinae, Heliconiini) are reduced in size compared to mesothoracic and metathoracic legs. They have no apparent function in males, but are used by females for drumming on host plants, a behavior related to oviposition site selection. Here, taking into account all recognized lineages of heliconian butterflies, we described their tarsi using optical and scanning electron microscopy and searched for podite fusions and losses, and analyzed allometry at the static, ontogenetic and phylogenetic levels. Female tarsi were similar, club-shaped, showing from four to five tarsomeres, each bearing sensilla chaetica and trichodea. Male tarsi were cylindrical, formed from five (early diverging lineages) to one (descendant lineages) either partially or totally fused tarsomeres, all deprived of sensilla. Pretarsi were reduced in both sexes, in some species being either vestigial or absent. Tarsal lengths were smaller for males in almost all species. An abrupt decrease in size was detected for the prothoracic legs during molting to the last larval instar at both histological and morphometric levels. In both sexes, most allometric coefficients found at the population level for the prothoracic legs were negative compared to the mesothoracic leg and also to wings. Prothoracic tarsi decreased proportionally in size over evolutionary time; the largest and smallest values being found for nodes of the oldest and youngest lineages, respectively. Our results demonstrate that evolution of the prothoracic leg in heliconian butterflies has been based on losses and fusions of podites, in association with negative size allometry at static, ontogenetic and phylogenetic levels. These processes have been more pronounced in males. Our study provided further support to the hypothesis that evolution of these leg structures is driven by females, by changing their use from walking to drumming during oviposition site selection. In males the leg would have been selected against due to absence of function and thus progressively reduced in size, in association with podites fusions and lost.

      PubDate: 2017-04-26T15:28:16Z
      DOI: 10.1016/j.asd.2017.03.008
  • Mantisbot is a robotic model of visually guided motion in the praying
    • Authors: Nicholas S. Szczecinski; Andrew P. Getsy; Joshua P. Martin; Roy E. Ritzmann; Roger D. Quinn
      Abstract: Publication date: Available online 28 March 2017
      Source:Arthropod Structure & Development
      Author(s): Nicholas S. Szczecinski, Andrew P. Getsy, Joshua P. Martin, Roy E. Ritzmann, Roger D. Quinn
      Insects use highly distributed nervous systems to process exteroception from head sensors, compare that information with state-based goals, and direct posture or locomotion toward those goals. To study how descending commands from brain centers produce coordinated, goal-directed motion in distributed nervous systems, we have constructed a conductance-based neural system for our robot MantisBot, a 29 degree-of-freedom, 13.3:1 scale praying mantis robot. Using the literature on mantis prey tracking and insect locomotion, we designed a hierarchical, distributed neural controller that establishes the goal, coordinates different joints, and executes prey-tracking motion. In our controller, brain networks perceive the location of prey and predict its future location, store this location in memory, and formulate descending commands for ballistic saccades like those seen in the animal. The descending commands are simple, indicating only 1) whether the robot should walk or stand still, and 2) the intended direction of motion. Each joint's controller uses the descending commands differently to alter sensory-motor interactions, changing the sensory pathways that coordinate the joints' central pattern generators into one cohesive motion. Experiments with one leg of MantisBot show that visual input produces simple descending commands that alter walking kinematics, change the walking direction in a predictable manner, enact reflex reversals when necessary, and can control both static posture and locomotion with the same network.

      PubDate: 2017-03-28T13:51:22Z
      DOI: 10.1016/j.asd.2017.03.001
  • Using insects to drive mobile robots — hybrid robots bridge the gap
           between biological and artificial systems
    • Authors: Noriyasu Ando; Ryohei Kanzaki
      Abstract: Publication date: Available online 18 March 2017
      Source:Arthropod Structure & Development
      Author(s): Noriyasu Ando, Ryohei Kanzaki
      The use of mobile robots is an effective method of validating sensory–motor models of animals in a real environment. The well-identified insect sensory–motor systems have been the major targets for modeling. Furthermore, mobile robots implemented with such insect models attract engineers who aim to avail advantages from organisms. However, directly comparing the robots with real insects is still difficult, even if we successfully model the biological systems, because of the physical differences between them. We developed a hybrid robot to bridge the gap. This hybrid robot is an insect-controlled robot, in which a tethered male silkmoth (Bombyx mori) drives the robot in order to localize an odor source. This robot has the following three advantages: 1) from a biomimetic perspective, the robot enables us to evaluate the potential performance of future insect-mimetic robots; 2) from a biological perspective, the robot enables us to manipulate the closed-loop of an onboard insect for further understanding of its sensory–motor system; and 3) the robot enables comparison with insect models as a reference biological system. In this paper, we review the recent works regarding insect-controlled robots and discuss the significance for both engineering and biology.
      Graphical abstract image

      PubDate: 2017-03-21T13:14:18Z
      DOI: 10.1016/j.asd.2017.02.003
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