Open Access
Translator Disclaimer
1 January 2020 Hypogastrura arnei (Collembola, Hypogastruridae), a remarkable new species from the Appalachians (USA)
Dariusz Skarżyński
Author Affiliations +
Abstract

Hypogastrura arnei sp. nov. is described from the USA. This species has a unique combination of morphological characters: an oval and slightly flattened body, a coarse tegumental granulation, a plurichaetotic dorsal chaetotaxy, antennal segment IV with 4-6 lateral sensilla and 1 dorsal cylindrical sensillum, a moderately modified furca and minute anal spines without papilla. The new species is closely related to H. iwamuraiYosii, 1960, H. reticulataBörner, 1909 and several members of the nivicola (= socialis), packardi (= sahlbergi) and crassaegranulata groups sensu Christiansen & Bellinger (1980), Babenko et al. (1994) and Skarżyński (2009).

INTRODUCTION

Hypogastrura Bourlet, 1839, comprising 170 species (Bellinger et al., 2019), is the largest collembolan genus within the family Hypogastruridae. Although the genus is considered cosmopolitan, the vast majority of species lives in the temperate climatic zone of the northern hemisphere. At present, about one hundred species are known in the Palaearctic (Babenko et al., 1994; Thibaud et al., 2004; Babenko & Fjellberg, 2006; Skarżyński, 2006a, b, 2009, 2010, 2011; Fanciulli & Dallai, 2008; Jiang & Chen, 2008; Skarżyński & Kaprus, 2009; Jiang & Yin, 2010, 2012; Skarżyński & Babenko, 2009; Jia et al., 2011; Jiang et al., 2011; Dányi, 2013, Kahrarian et al., 2013; Skarżyński et al., 2017), and only about forty in the Nearctic (Christiansen & Bellinger, 1998; Babenko & Fjellberg, 2006; Skarżyński, 2007; Bernard, 2015). Undoubtedly our knowledge of Nearctic Hypogastrura is insufficient and the number of recorded species is underestimated. In the Hypogastrura material from the Appalachians (USA), which I obtained from Dr Arne Fjellberg, I found a species new to science. Its description is given below.

MATERIAL AND METHODS

Specimens stored in alcohol were cleared in Nesbitt's fluid (chloral hydrate, concentrated hydrochloric acid, distilled water), slide-mounted in a mixed medium of distilled water, arabic gum, glycerol and chloral hydrate, and studied using a Nikon Eclipse E600 phase contrast microscope. Figures were drawn using a camera lucida. Terminology in the description follows that given in Fjellberg (1984, 1999) and Thibaud et al. (2004).

TAXONOMIC PART

Hypogastrura arnei sp. nov.
Figs 1-8

  • Type material: Male holotype, previously in alcohol, now mounted on permanent slide; USA, Tennessee, Sevier County, Great Smoky Mountains National Park, Clingman's Dome (WGS84 35.56212, -83.50425; 1980 m a.s.l.), moss, fir litter, sample number 07.197; 07.06.2007; leg. A. Fjellberg. – Paratypes: 10 females, 10 males, same data as for holotype. Holotype and 13 paratypes deposited in the National Museum of Natural History, Smithsonian Institution, Washington D.C., USA; 5 paratypes in the University of Tennessee Entomology Museum, Knoxville, Tennessee, USA; 2 paratypes in the Muséum d'histoire naturelle de Genève, Switzerland.

  • Other material: Male on slide; USA, North Carolina, Yancey County, Blue Ridge Parkway, Balsam Gap Overlook (WGS84 35.74837, -82.33337; 1650 m a.s.l.), red spruce litter, sample number 07.167; 04.06.2007; leg. A. Fjellberg (deposited in the University of Tennessee Entomology Museum, Knoxville, Tennessee).

  • Comparative material examined: Hypogastrura iwamurai Yosii, 1960: female, previously in alcohol, now mounted on permanent slide, 16 specimens in alcohol; Japan, Hyonosen; 28.08.1938; leg. Yosii. – Hypogastrura reticulata Börner, 1909: female, previously in alcohol, now mounted on permanent slide, about 50 specimens in alcohol; Japan, Daimonji, Kyoto; 20.12.1953; leg. R. Yosii. All specimens deposited in the Muséum d'histoire naturelle de Genève, Switzerland.

  • Etymology: This species is dedicated to Dr Arne Fjellberg, an excellent specialist in Collembola.

  • Diagnosis: Body oval and slightly flattened. Tegumental granulation coarse. Chaetotaxy plurichaetotic. Antennal segment IV with 4-6 lateral sensilla and 1 dorsal cylindrical sensillum. Postantennal organ equal to or slightly smaller than neighboring ocelli. Labrum with distinct apical papillae. Tibiotarsi with one clavate tenent hair. Empodial lamellae broad. Ventral tube with 4 + 4 setae. Retinaculum with 4 + 4 teeth. Dens with 7 setae and fine, uniform granulation including some slightly larger granules in distal part. Mucro with low lamellae and small subapical tooth. Anal spines minute, papilla absent.

  • Description: Body length 1.1-1.6 mm. Body oval (Fig. 1) and slightly flattened, abdominal segment VI short and rounded at tip. Color in alcohol uniformly dark blue-grey, eye-patches black. Tegumental granulation coarse and uniform, 3-5 granules between setae p1 on abdominal tergum V (Fig. 3).

  • Chaetotaxy of head typical of the genus, with complete set of v-setae. Setae slightly different in lengths (especially on last abdominal segments) and curved. Body sensilla (s) about two times longer than microsetae, fine and smooth. Thoracic tergum I with 3 + 3 setae. Dorsal chaetotaxy of thoracic terga II-III and abdominal terga III-VI as in Figs 2-3: setae m2, m3 m4, m6 and m6, present. Between thoracic tergum II and end of body (especially on abdominal terga IV and V) additional setae present (plurichaetosis). Subcoxae I, II, III with 1, 4, 4 setae, respectively. Microsensillum on thoracic tergum II present.

  • Antennal segment IV with simple apical vesicle (av), subapical organite (or), microsensillum (ms), 4-6 lateral sensilla and 1 dorsal cylindrical curved, blunt sensillum (Fig. 6) and 5-7 short pointed setae in ventral field. Antennal segment III organ with two long (outer) and two short (inner) sensilla (Fig. 6). Microsensillum on antennal segment III present. Antennal segment I with 8 setae (seta p' present).

  • Ocelli: 8 + 8. Postantennal organ equal to or slightly smaller than neighboring ocelli, with four lobes, the anterior pair slightly larger than posterior one. Large accessory boss present (Fig. 7). Labrum with six apical papillae (four large and two small marginal ones). Labral setae 5, 5, 4, prelabrals 4. Maxillary head of H. tullbergi type (Fjellberg, 1984: fig. 6). Labial palp as shown in Fjellberg (1999: fig. 6). Outer maxillary lobe with two sublobal hairs.

  • Tibiotarsi I, II, III with 19, 19, 18 setae, respectively. Apical seta A1 clavate and slightly longer than inner edge of claw. Claws with inner tooth. Empodial appendage with broad basal lamella and apical filament reaching slightly beyond inner tooth of unguis (Fig. 5).

  • Ventral tube with four setae on each side. Retinaculum with 4 + 4 teeth.

  • Furca well developed (ratio dens + mucro/inner edge of claw III = 2.7-2.9). Dorsal side of dens with 7 setae and with fine, uniform granulation and some slightly larger but not tooth-like granules in distal part. Apical swelling absent. Mucro with low lateral lamellae (outer one higher than inner one) fusing below apex and forming small subapical tooth. Ratio dens/mucro = 2.2-2.4 (Fig. 8).

  • Anal spines narrowly conical, minute (equal to or slightly longer than neighboring granuli, ratio anal spine/inner edge of claw III = 0.1-0.15), papilla absent (Fig. 4).

  • Remarks: Hypogastrura arnei sp. nov. is remarkable for its oval and slightly flattened body, coarse tegumental granulation, plurichaetotic chaetotaxy, antennal segment IV with 4-6 lateral sensilla and 1 dorsal cylindrical, blunt sensillum, moderately modified furca and minute anal spines without papilla. The unusual body shape of the new species deserves special attention. Among known species only H. iwamurai Yosii, 1960 seems to be similar in this respect. According to Yosii (1960) the body of that species is „somewhat dorsoventrally flattened as in Ceratrimeria”. The examination of some specimens of H. iwamurai showed that the body of this species is oval and slightly flattened, but its abdominal segment VI is long and tapering posteriorly, while it is short and rounded at the tip in H. arnei sp. nov. Moreover, these two species differ considerably in body size (1.1-1.6 mm in H. arnei sp. nov. versus “up to 2.5 mm” in H. iwamurai), in tegumental granulation (3-5 granules between setae p1 on abdominal tergum V in H. arnei sp. nov. versus 12 in H. iwamurai) and in size and shape of the anal spines (narrow-conical, minute, without papilla in H. arnei sp. nov. versus short, thick, slightly curved, raised on high papillae in H. iwamurai).

  • Hypogastrura arnei sp. nov. differs also from all the remaining representatives of the genus in the arrangement of cylindrical sensilla on antennal segment IV. Although the new species shares a tendency towards a greater number of lateral sensilla with members of the nivicola (= socialis), packardi (= sahlbergi) and crassaegranulata groups sensu Christiansen & Bellinger (1980), Babenko et al. (1994) and Skarżyński (2009), the presence of a single dorsal sensillum (versus usually 3) places this species at an isolated position. Nevertheless, H. arnei sp. nov. is similar to some species of all these groups. Coarse body granulation and an only moderately modified furca (tooth-like granules, apical swelling on dens and large subapical tooth on mucro absent) make H. arnei sp. nov. similar to several Nearctic and Palearctic species/forms. Hypogastrura macrotuberculata Hammer, 1953 from Alaska and Canada (Babenko et al., 2019) also has a coarse tegumental granulation, but mainly on the last abdominal terga. Moreover, that species is characterized by the lack of plurichaetosis, by the presence of 1+1 v-setae (rarely 1+2 or 2+2) on the head and by small but not minute anal spines on clear papillae. Hypogastrura reticulata sensu Hammer (1953) nec Börner, 1909, an incompletely described species (chaetotaxy unknown) from the Arctic part of Canada, has a special feature that makes it easily distinguishable, i.e. the presence of reticular structures all over the body segments. In addition, it has a hook-like mucro and small but not minute anal spines on clear papillae, and according to Yosii (1960) 1 + 1 v-setae on the head. Among the Palearctic species similar to H. arnei sp. nov. are the following members of the crassaegranulata group: H. chouardi Cassagnau, 1959 (Pyrenees) and H. hohi Babenko in Babenko et al. (1994) (Caucasus) and H. reticulata Börner, 1909 (Japan). The first two, having more than 4 + 4 setae on the ventral tube and a typical dorsal chaetotaxy (plurichaetosis absent), are easy to distinguish. The third, of which I examined some specimens, is unique due to combination of large body size (2.5 mm) and the presence of reticular structures all over the body segments.

  • Coarse body granulation and a moderately modified furca are also present in summer forms of cyclomorphic species of the nivicola (= socialis) group: H. kelmendica Peja, 1985 (Albania, Croatia, Poland), H. lapponica (Axelson, 1902) (Palaearctic) and H. simsi Hart & Waltz, 1995 (USA). Their summer and winter forms clearly differ from H. arnei sp. nov. in small but not minute anal spines on distinct papillae, and by the abdominal tergum IV without setae m1 (present in H. kelmendica), by a short mucro, ratio dens/mucro about 4 (in H. lapponica) and by the dens projecting beyond the apex of the mucro (in H. simsi) (Axelson, 1902; Peja, 1985; Babenko et al., 1994; Hart & Waltz, 1995; Christiansen & Bellinger, 1998; Skarżyński & Smolis, 2003).

  • Finally, plurichaetotic chaetotaxy relates the new species to some members of the packardi (= sahlbergi) group: H. austriaca Babenko & Thibaud, 1990 (Austria, Burgenland), H. pomorskii Skarżyński, 2010 (Tien Shan), H. tatrica (Stach, 1949) (N Carpathians) and H. tchabensis Babenko in Babenko et al. (1994) (foreland of the Caucasus) and the nivicola (= socialis) group: H. bokusi Yosii, 1961. Nevertheless, the first four species are distinct, having a fine tegumental granulation and numerous setae (at least 7 + 7) on the ventral tube (Stach, 1949; Babenko & Thibaud, 1990; Babenko et al., 1994; Skarżyński, 2010). Hypogastrura bokusi has tooth-like granules on dens and a large subapical tooth on the mucro (Yosii, 1961).

  • Figs 1-8.

    Hypogastrura arnei sp. nov. (1) Habitus, dorsal view. (2) Chaetotaxy of thoracic terga II-III. (3) Chaetotaxy of abdominal terga III-VI. (4) Anal spine. (5) Claw III with empodial appendage. (6) Chaetotaxy of antennal segments III-IV, dorsal view. (7) Postantennal organ and adjacent ocelli. (8) Dens and mucro of furca. Scale lines: 1; 2-3; 4; 5-8 to same scale. Abbreviations: av - apical vesicle; or - subapical organite; ms - microsensillum; a1 - setae of a-row; m1-6 - setae of m-row; p1 - setae of p-row; s - body sensilla.

    img-z3-3_269.jpg

    ACKNOWLEDGEMENTS

    I wish to express my sincere thanks to Dr Arne Fjellberg (Tjøme, Norway) for providing material of H. arnei sp. nov. I am also grateful to Dr Peter Schwendinger (Muséum d'histoire naturelle de Genève, Switzerland) for the loan of H. iwamurai and H. reticulata material. Dr Anatoly Babenko (The Severtsov Institute of Ecology & Evolution, Russian Academy of Sciences, Moscow, Russia) kindly reviewed the manuscript.

    REFERENCES

    1.

    Axelson W.M. 1902. Diagnosen neuer Collembolen aus Finnland und angrenzenden Teilen des nordwestlichen Russlands. Meddelanden af Societas pro Fauna et Flora Fennica 28: 101–111. Google Scholar

    2.

    Babenko A., Fjellberg A. 2006. Collembola septentrionale. A catalogue of springtails of the Arctic regions. KMK Scientific Press Ltd ., Moscow , 190 pp. Google Scholar

    3.

    Babenko A., Thibaud J.-M. 1990. Eine neue Hypogastruride (Insecta: Collembola) aus Österreich. Zeitschrift der Arbeitsgemeinschaft Österreichischer Entomologen 42: 95–96. Google Scholar

    4.

    Babenko A.B., Chernova N.M., Potapov M.B., Stebaeva S.K. 1994. Collembola of Russia and adjacent countries. Family Hypogastruridae. Nauka , Moscow , 336 pp. Google Scholar

    5.

    Babenko A., Stebaeva S., Turnbull M.S. 2019. An updated checklist of Canadian and Alaskan Collembola. Zootaxa 4592(1): 1–125. Google Scholar

    6.

    Bellinger P.F., Christiansen K.A., Janssens F. 2019. Checklist of the Collembola of the World. Available at  http://www.collembola.org (accessed 15 April 2019). Google Scholar

    7.

    Bernard E.C. 2015. Redescriptions of Hypogastruridae and Onychiuridae (Collembola) described by David L. Wray. Zootaxa 3918: 301–338. Google Scholar

    8.

    Bourlet A. 1839. Mémoires sur les Podures. Mémoires de la Société des sciences de l'agriculture et des arts de Lille 1: 377–417. Google Scholar

    9.

    Börner C. 1909. Die Collembolenfauna Japans. (Vorläufige Mitteilung). Sitzungsberichte der Gesellschaft Naturforschender Freunde zu Berlin 2: 99–135. Google Scholar

    10.

    Cassagnau P. 1959. Faune française des Collemboles (IX). Les Hypogastrura s.l. du massif du Néouvielle (Hautes-Pyrénées). Remarques sur la chétotaxie des espèces. Vie et Milieu 9: 476–503. Google Scholar

    11.

    Christiansen K., Bellinger P. 1980. The Collembola of North America north of the Rio Grande. Grinnell College , Grinnell , 1321 pp. Google Scholar

    12.

    Christiansen K., Bellinger P. 1998. The Collembola of North America north of the Rio Grande. A taxonomic analysis. Grinnell College , Grinnell , 1520 pp. Google Scholar

    13.

    Dányi L. 2013. An undescribed Collembola species swarming on the Peloponnese (Greece). Opuscula Zoologica, Budapest 44 (suppl. 1): 157–166. Google Scholar

    14.

    Fanciulli P.P., Dallai R. 2008. Three new species of Collembola from north-east Italy. Zootaxa 1701: 15–28. Google Scholar

    15.

    Fjellberg A. 1984. Maxillary structures in Hypogastruridae (Collembola). Annales de la Société Royale Zoologique de Belgique 114: 89–99. Google Scholar

    16.

    Fjellberg A. 1999. The labial palp in Collembola. Zoologischer Anzeiger 237: 309–330. Google Scholar

    17.

    Hammer M. 1953. Investigations on the microfauna of northern Canada, part II. Collembola. Acta Antarctica 6: 5–107. Google Scholar

    18.

    Hart J.W., Waltz R.D. 1995. A new species and new synonym in the Hypogastrura (s. str.) nivicola group (Collembola: Hypogastruridae). Entomological News 106(2): 77–80. Google Scholar

    19.

    Jia J., Skarżyński D., Konikiewicz M. 2011. A taxonomic study on Hypogastrura Bourlet, 1839 (Collembola, Hypogastruridae) from China. Zootaxa 2981: 56–62. Google Scholar

    20.

    Jiang J., Chen J.X. 2008. A new species and a new species record of Hypogastrura (Collembola: Hypogastruridae) from China. Zootaxa 1846: 47–54. Google Scholar

    21.

    Jiang J., Yin W. 2010. Two new Hypogastrura species (Hypogastruridae, Collembola) from China. Zootaxa 2542: 48–60. Google Scholar

    22.

    Jiang J., Yin W. 2012. New Hypogastrura species and new distributional data for Hypogastrura distincta (Axelson 1902) from China (Collembola: Poduromorpha: Hypogastruridae). Annales de la Société entomologique de France 48: 115–122. Google Scholar

    23.

    Jiang J., Yin W., Chen J., Bernard E.C. 2011. Redescription of Hypogastrura gracilis, synonymy of Ceratophysella quinidentis with C. duplicispinosa, and additional information on C. adexilis (Collembola: Hypogastruridae). Zootaxa 2822: 41–51. Google Scholar

    24.

    Kahrarian M., Vafei-Shooshtari R., Skarżyński D., Konikiewicz M., Soleymannezhadyan E., Shayan Mehr M., Shams B. 2013. A new species and new records of the genus Hypogastrura Bourlet, 1839 (Collembola, Hypogastruridae) from Iran. Zootaxa 3709: 89–94. Google Scholar

    25.

    Peja N. 1985. Diagnoses préliminaires de quelques nouvelles espèces de Collemboles. Biologia Gallo-hellenica 10: 213–220. Google Scholar

    26.

    Skarżyński D. 2006a. A taxonomic revision of Hypogastrura crassaegranulata (Stach, 1949) (Collembola, Hypogastruridae). Zootaxa 1109: 27–37. Google Scholar

    27.

    Skarżyński, D. 2006b. A new species and a new record of the genus Hypogastrura Bourlet, 1839 (Collembola, Hypogastruridae) from Poland. Acta zoologica cracoviensia 49B(1–2): 83–87. Google Scholar

    28.

    Skarżyński D. 2007. Hypogastrura hargrovei sp. n., a new species of the family Hypogastruridae (Collembola) with highly modified mouthparts. Insect Systematics and Evolution 38: 201–204. Google Scholar

    29.

    Skarżyński D. 2009. Reassessment of the taxonomic position of Hypogastrura monticola Stach, 1946 (Collembola, Hypogastruridae). Soil Organisms 81: 77–83 Google Scholar

    30.

    Skarżyński D. 2010. Hypogastrura pomorskii n. sp. from Kyrgyzstan and notes on the related species H. tatrica (Stach, 1949) (Collembola: Hypogastruridae). Acta Zoologica Academiae Scientiarum Hungaricae 56(3): 257–263. Google Scholar

    31.

    Skarżyński D. 2011. A taxonomic study on some Alpine Hypogastrura Bourlet, 1839 (Collembola, Hypogastruridae). Zootaxa 2786: 62–68. Google Scholar

    32.

    Skarżyński D., Babenko A. 2009. Description of two new species of the crassaegranulata group of the genus Hypogastrura Bourlet, 1839 (Collembola, Hypogastruridae) from the Caucasus, with notes on some related species. Entomologica Fennica 20(4): 275–280. Google Scholar

    33.

    Skarżyński D., Kaprus I.J. 2009. A new species and a new interesting record of the genus Hypogastrura Bourlet, 1839 (Collembola, Hypogastruridae) from Ukraine. Acta Zoologica Academiae Scientiarum Hungaricae 55(1): 23–30. Google Scholar

    34.

    Skarżyński D., Smolis A. 2003. Notes on Hypogastrura kelmendica Peja, 1985 (Collembola, Hypogastruridae), a springtail species new for the Polish fauna. Polskie Pismo Entomologiczne 72(2): 105–109. Google Scholar

    35.

    Skarżyński D., Kahrarian M., Piwnik A., Zawisza M. 2017. Description of Hypogastrura ellisi sp. n. (Collembola, Hypogastruridae), with notes on H. tethyca Ellis and the trybomi group. ZooKeys 719: 45–57. Google Scholar

    36.

    Stach J. 1949. The apterygotan fauna of Poland in relation to the world fauna of this group of insects. Families Neogastruridae and Brachystomellidae. Acta Monographica Musei Historiae Naturalis, Kraków 2: 1–341. Google Scholar

    37.

    Thibaud J.-M., Schulz H.-J., Gama Assalino M.M. da 2004. Synopses on Palaearctic Collembola, Volume 4, Hypogastruridae. Staatliches Museum für Naturkunde , Görlitz, 287 pp. Google Scholar

    38.

    Yosii R. 1960. Studies on the Collembolan genus Hypogastrura. American Middland Naturalist 64: 257–281. Google Scholar

    39.

    Yosii R. 1961. Studies on Japanese Collembola VII. Cryophilous species of the Niigata Prefecture. Bulletin of the Nagaoka Municipal Science Museum 2: 14–19. Google Scholar
    Dariusz Skarżyński "Hypogastrura arnei (Collembola, Hypogastruridae), a remarkable new species from the Appalachians (USA)," Revue suisse de Zoologie 126(2), 269-273, (1 January 2020). https://doi.org/10.5281/zenodo.3463465
    Accepted: 24 July 2019; Published: 1 January 2020
    JOURNAL ARTICLE
    5 PAGES


    Share
    SHARE
    KEYWORDS
    Nearctic
    North America
    springtails
    taxonomy
    RIGHTS & PERMISSIONS
    Get copyright permission
    Back to Top