Opusc. Zool. Budapest, 2013, 44(1): 23–46 Synopsis of the Oxyethira flavicornis species group with new Japanese Oxyethira species (Trichoptera, Hydroptilidae) J. OLÁH1 and T. ITO2 Prof. János Oláh, Tarján u. 28, H-4032 Debrecen, Hungary. E-mail: [email protected] Dr. Tomiko Ito, Hokkaido Aquatic Biology, Hakuyo-cho, 3-3-5, Eniwa, Hokkaido 061-1434, Japan. E-mail: [email protected] Abstract. A brief synopsis of the Oxyethira flavicornis species group is produced by the examination of type materials. Diagrammatic drawings with similar style were prepared for all the known and for the new species. Short description of genus Oxyethira, subgenus Oxyethira, species group of Oxyethira flavicornis are presented together with the description of five species clusters: O. datra new species cluster, O. ecornuta new species cluster, O. flavicornis new species cluster, O. hiroshima new species cluster, O. tiunovae new species cluster. Five new species are described from the O. flavicornis species group: O chitosea sp. n., O. hena sp. n., O. hiroshima sp. n., O. kakida sp. n., O. mekunna sp. n. One new species is described from the Oxyethira grisea species group: Oxyethira ozea sp. n. and two new species from the Oxyethira ramosa species group: Oxyethira miea sp. n., Oxyethira okinawa sp. n. Keywords. Caddisflies, Oxyethira, new species, Japan. INTRODUCTION 1997 from China and O. tiunovae Arefina & Armitage, 2003 from Russia (Far-East). Th e micro-caddisfly genus Oxyethira is among Malicky & Chantaramongol (2007) examined the largest genera in the family Hydroptilidae an Oxyethira specimen with flat and split para- and has a worldwide distribution. The Oxyethira mere from Hokkaido and compared it with the flavicornis species group has been erected by published drawings of O. datra and O. josifovi. Marshall (1979). She has established this group They have synonymised O. josifovi as a junior by broad genital morphological character range, synonym of O. datra and thus identified the based on the absence of a median ventral lobe on Hokkaido specimen as O. datra. Malicky sent his the fused gonopods and on the presence of broad, drawings of the Hokkaido specimen to the first widely separated paraproct. This broadly defined author (J.O.). Examination without special care on diagnosis covered several species from three paramere revealed no differences. Nozaki has species groups redefined later: O. falcata, O. collected specimens from Honshu and sent them flavicornis and O. ramosa. Kelley (1984, 1985) to the first author to compare with O. datra. The modified this broad concept and restricted the second author (T.I.) borrowed Malicky’s spe- group characters to flattened paramere that is split cimen and took several genitalia photos in 2008– into two strands. As a result two species remained 2009. Actually the lack of understanding on the in O. flavicornis species group defined narrowly: taxonomic position of this Hokkaido specimen O. ecornuta Morton, 1893 and O. flavicornis initiated this research. We have completed a brief (Pictet, 1834). Later, four new species have been revision of the entire species group. Reexamining discovered having flattened and split paramere the drawings and genitalia photos as well as and added to the species group: O. datra Oláh, comparing it with more specimens and with all 1989 from Vietnam, O. josifovi Kumanski, 1990 the related taxa, we have found it as a new species from Korea, O. sichuanensis Yang & Kelley, O. kakida sp. nov. _______________________________________________________________________________________________________ urn:lsid:zoobank.org:pub:C32D7E94-BD4D-4F9E-9B9C-78261A33E1D0 HU ISSN 2063-1588 (online), HU ISSN 0237-5419 (print) Oláh & Ito: Synopsis of the Oxyethira flavicornis species group with new Japanese Oxyethira species Recently emerging new perspectives open examined specimens. When sufficient material more sophisticated approaches to discover diverse was available the head and thorax (except wings) fine structures in searching stable traits to dis- were macerated together with the abdomen. The tinguish specific state of populations without duration of the treatment is adjusted individually molecular studies. Phylogenetic species concept to the effectiveness of clearing process which de- and the sexual selection theory were applied pends on the species or even on the nutritive state effectively in the taxonomy of the obscured Chae- of tissues or on the physiological condition of the topteryx rugulosa species group (Oláh et al. specimens. The digested animals were subse- 2012). The phallic organ and particularly one of quently transferred to distilled water and the ma- its formerly neglected substructure, the subapical cerated tissue was removed mechanically by fine lateral lobes of the aedeagus as well as the anal tipped forceps and needles. The cleared animal tube of the females proved to be very diverse and was transferred to 80% ethyl alcohol, and to stable traits to separate and distinguish among glycerine for examination under microscope. Dif- closely related species. In the present study on ferent sized pins modified to supporting ring bot- Oxyethira flavicornis species group we have tom were used to hold and stabilise the animal or found another phallic structure, the paramere as a the genitalia in lateral, dorsal and ventral position promising diverse and stable character to dis- for drawing. tinguish among closely related species. In this study we have re-examined all the known and the Improved visualization newly described species and demonstrate that parameres are differing sufficiently among spe- Examination of fine genital structures is not cies. Key question remained however how to easy in Hydroptilidae. On so small an object as examine, visualise in three dimensions and how to hydroptilids it may be very difficult to visualise draw these very complex and plane sensitive and understand genital substructures and func- structures. tions with absolute certainty. The phallic organ and its very complex parameres are not consistent, MATERIAL AND METHODS in most of the published figures showing incon- sistencies. Positive identification is most possible This paper is based upon the Oxyethira mate- only with teasing out of the entire phallic organ, rial collected by Japanese scientists from various not only the phallic tip. In practice teasing the localities from Hokkaido to Ryukyu Islands and entire phallic organ either anterad or posterad may set aside during the last 37 years. In order to injure or distort those parts of the parameres observe morphological details on the total body as which are directed in opposite of teasing. Espe- well as to prevent the loss of the dissected small cially when teasing the phallic organ anterad, the structures the entire animal was macerated in a complex arm of the paramere is usually detached small glass beaker of 25 cm3 with nearly boiling and hooked in its original position. Following the 10% KOH solution for 5–15 minutes. The setal natural movement of the phallic organ as it func- wart pattern of the head and thorax in all the tions by teasing out the aedeagus and paramere anatomical planes are rarely described and figured together posterad results free structure without in species descriptions, or are performed only on significant injuries. It is advisable to examine se- intact animals, without maceration of tissue. In veral specimens with properly withdrawn phallic many intact species the wart and groove patterns organ to understand in details the structure and are poorly visible and frequently indiscernible, function of an unknown paramere. The in situ especially if the warts have the same colour as the paramere position is highly dependent on the pre cranial sclerites, or if the setae on the warts are or postcopulatory state of the animals. Moreover not detached and the warts are densely covered by only a little plane change creates significant alte- intact setae. Clearing the entire body thus gave us ration how we see the very complex structure of useful information on the setal wart pattern for the paramere under microscope. 24 Oláh & Ito: Synopsis of the Oxyethira flavicornis species group with new Japanese Oxyethira species Intact genitalia of these tiny hairy creatures are the compound microscope may help to detect and usually concealed by dense pilosity. In our present understand difficult parts of the genitalia. The state of understanding genital appendages or peri- shape, connections, interactions and articulations phallic organs of the hydroptilids cannot be iden- of the small and frequently weakly pigmented tified with high degree of certainty. Without structures require experience. Permanent move- cleaning in KOH, and without denuding it pro- ment and maceration with fine tipped pins of the perly, that is mechanically removing setae at least properly cleared and denuded genitalia under the from pregenital segment VIII as well as removing stereomicroscope, as well as under inverted com- internal content properly it is rarely possible to pound microscope with large working depth, help identify correctly specimens to species level. The us to detect the otherwise indiscernible structures setae mask the otherwise visible free genital of various articulations. structures projecting out of the cover of segment IX. In the case of Oxyethira, Catoxyethira and Diagrammatic and habitus drawings several Leucotrichiini the enlarged and enforced segment VIII frequently produces a second layer For Trichoptera, illustrations of the genitalia covering the entire segment IX together with its are the most important component in species des- substructures projecting out free. The setal cover criptions. It is especially important to prepare usually hides essential parts of the basal articu- drawings that are clearly understood and complete lating sections of the genital structural elements, for visualization of the hydroptilids. These tiny especially those of the paraprocts, gonopods and animals dispose difficulties in visual detection and basal plate of the gonopods which are already understanding the function of their genitalia. This under cover of segment IX. After macerating the is reflected by a lack of standard and by the highly remaining setae should be removed. Perfectly varying quality of illustrations of genitalia in denuded genitalia without setae but with intact species descriptions. There are two basic types of alveoli, represents what is required for the obser- genital drawings in scientific illustration with vation of fine structures of the periphallic ele- several intermediate solutions: diagrammatic and ments, their articulations and interactions. Parti- habitus drawings. cularly taxonomically important is the articulation between paraprocts, gonopods and the basal plate Diagrammatic, structural line or contour line of the gonopods. drawings are symbols of ideas visualized by ima- gery instead of by linguistic or algebraic means. A high quality stereomicroscope under highest Diagrammatic drawings explain the genital resolution is required to be able to observe impor- structure by outlining its parts and their relati- tant three-dimensional structures, instead of using onships by using lines. A single line creating an the higher magnification of compound micros- outline of an object can show the length, height, cope. Stereomicroscope uses 2 separate optical width and even details of what is being studied. paths to provide different viewing angles to the The word contour refers to an outline of the geni- left and right eyes. It therefore produces a three- tal substructures. Traditionally, it presents only dimensional visualization of the genital structures their exterior edges. A plain contour is one line with great working distance and sufficient depth that is connected with no shading, emphasizing of field. However, higher resolution induces the shell of the object. Of course line drawing smaller depth of field and working distance. The does not capture all of the information of the stereomicroscope should not be confused with a genitalia, instead it usually only captures either compound microscope equipped with double the interior or the exterior contours. Diagramma- eyepieces. In a compound microscope, both eyes tic drawings are reasoning by means of simple see the same image, and the binocular eyepieces visual representations and are about the under- simply provide greater viewing comfort. standing of concepts and ideas: how the research- However, the higher magnification potential of er understands the structure and function of a 25 Oláh & Ito: Synopsis of the Oxyethira flavicornis species group with new Japanese Oxyethira species species. The idea or concept is visualized with the In our diagrammatic drawings we use different use of clear-cut drafting, plan, sketch, line-draw- linetypes with various thickness applying standard ing, or outline-drawing. Diagrammatic drawings metric lines of 0.18, 0.35 and 0.70 mm (Rotring, are designed to demonstrate or explain how geni- Isograph). Thickness of contour lines represents tal structure works or to clarify the relationship the visibility of structures depending highly on between the parts of the entire genitalia. The their sclerotization. To suggest that something is Occam’s razor of lex parsimoniae, the principle of less sclerotized, membranous or weakly visible parsimony is behind the diagrammatic type of we apply thinner lines as well as thicker lines for drawings. heavily sclerotized structures. Dotted lines are used to contour structure under cover of other Habitus drawings are similar to photos. They structures and to outline segments VII and VIII. could be more precise and exact. They are more The special structural modifications developed on descriptive, more detailed, more artistic. However segments VII and VIII, like dentate patches, they are less about simple visualization of func- special processes or spiny outgrowths are empha- tional ideas and concepts: how a researcher’s un- sized by drawing with continuous lines. Dotted derstanding helps in simple presentation. Simple segment VIII with continuous drawn lines of its structural and functional imagery is frequently special structures were frequently slightly or masked by detailed surface sculptures or by vari- entirely shifted in order not to overlap with seg- ous setal densities. Connections, interactions and ment IX and its periphallic organs. When straight, articulations between the periphallic organs is curved or crooked lines meet or intersect, they usually not indicated. Habitus drawings are usu- form corners and angles, in order to symbolise at ally preferred by scientists having more artistic least minimal signs of three-dimensional space we ability and practice to elaborate shading by apply microcarving for these meeting points, that stipple, parallel lines of various spacing. is usually not applied in diagrammatic drawings. Preparation of drawings Nomenclature applied The plane of view is never perfect and we The terminology applied to grooves, setal made no special procedures of grid, matrix or ref- warts and genital structures follows that of by lection to produce absolute mirror symmetry Oláh & Johanson (2007, 2008). The following when illustrating the hydroptilids. Instead, the terminologies were used to qualify the dimensions genital structures were drawn exactly as seen in and extensions of genital structural elements: (1) the microscope. On the drawings, setae were short or long for length dimension on the represented only by their alveoli, and their density longitudinal direction of coronal plane along the is only symbolic. If essential, the setae length or anteroposterior axis; (2) low or high (traditionally setae shape are presented by drawing single or shallow or deep especially for excisions) for few setae only. The genital structure was traced height dimension on the vertical direction of the by pencil on white paper using a drawing tube sagittal plane along the dorsoventral axis and (3) mounted on a WILD M3Z microscope at 260– narrow or wide (broad) on the lateral direction of 416x magnification. Drawings were usually pre- the transversal plane along the mediolateral or pared in lateral, dorsal and ventral view. The left-right axis. lateral view is the most complete, comprising the pregenital segments VII-VIII, genital segment IX, postgenital segment X, and the entire set of peri- In hydroptilids all the basic periphallic struc- phallic organs: cerci, paraprocts, gonopods and tures, together with genital segment IX and post- the basal palate of the gonopods. The final illust- genital segment X of the genital groundplan are rations were prepared by enlarging the original present. Cerci are seldom observed in Hydropti- pencil drawings and re-drawn on transparent lidae. Segment X frequently obscure and difficult paper by Black India Ink. to visualize. Usually located apicad of segment IX 26 Oláh & Ito: Synopsis of the Oxyethira flavicornis species group with new Japanese Oxyethira species and dorsad of phallic organ, frequently fused with Biology and Soil Science, Russian Academy of segment IX. Less sclerotized, sometimes membra- Sciences, Vladivostok, (IBSS RAS). Natural nous, especially on cleared specimens difficult to History Museum and Institute of CHIBA, Japan discern its exact shape and boundaries. At higher (CMB-ZI). Nanjing Agricultural University magnification its surface microsculpture seldom (NAU). Oláh Private Collection (OPC), under glabrous, frequently coriaceous covered with mic- national protection by the Hungarian Natural rotrichia or tomentose, sometimes granulate, fove- History Museum. Ito Private Collection (IPC) olate, punctulated often canaliculated, striated longitudinally or transversally, rugulose and nar- TAXONOMY row folded. The periphallic structures of para- proct, gonopods and basal plate of gonopods are Genus Oxyethira Eaton, 1873 frequently vestigial or strongly modified and were Diagnosis. Segment IX completely retracted commonly present under various names in lite- within segment VIII, venter IX pointed or round- rature. The terminology systems by various ed anteriorly, not truncate or excised mesally, authors are listed below. caudal end of venter IX indistinct, fused with gonopods. Based upon a selection of 15 plesio- Paraproct. Ventral part of segment X in Oxy- morphic and apomorphic character states (Oláh & ethira spp. (Ross 1944), according to Kelley Johanson 2011), the genus Oxyethira is defined in (1984) surprising for segment X to be present the tribe Hydroptilini as having (1) 3 ocelli pre- ventrad of phallus. Process above claspers at sent. (2) Tentorium vestigial. It means that anteri- Stactobiella palmata (Ross 1944). Apophyses or tentorial pits present with the basal third of anterior tentorial arms and the posterior two third supérieure (Vaillant 1951). Semiannular sclerite of this arms disappeared; tentorial bridge forming with two spine-like asymmetric processes (Niel- a closed loop together with the posterior tentorial sen 1957). Appendices supérieure (Schmid 1959, arms. (3) Length of first and second segments of 1983). Ventral plate of segment X when fused maxillary palp shorter than wide. (4) Number of (Marshall 1979). Parameres at Orthotrichia antennal segments 24–47. (5) Terminal antennal (Wells 1979). Aedeagal sheath at Paroxyethira segment with blunt apex. (6) Clothing antennal (Kelley 1989). Pair of spines arising basoventrally setae whorled fimbriate. (7) Scapus unmodified. on segment X at Hellyethira davidi (Wells 2005). (8) Mesoscutellum subtriangular with convex Subgenital appendages (Marshall 1979). Inter- anterior margin. (9) Mesoscutellum without trans- mediate appendages (Marshall 1979). Lateral versal suture. (10) Metascutellum convexly subtri- penis-sheets (Marshall 1979). Parameres when angular. (11) Spur count 034. (12) Abdominal paired (Marshall 1979). Subgenital plate (Mar- segments unmodified. (13) Dorsolateral lobes on shall 1979). Lower penis cover (Marshall 1979). segment IX present. (14) Segment IX semicy- lindrical. (15) Segment X indistinct. (16) Cerci Gonopods. Inferior appendages (McLachlan absent. (17) Paraproct highly modified. (18) Har- 1874–1880). Claspers (Ross 1938). Apophyses pagones absent. inférieure (Vaillant 1951). Appendices inférieure (Schmid 1959, 1983). Subgenus Oxyethira Eaton, 1873 Diagnosis. The subgenus Oxyethira is the larg- Basal plate of gonopods. Bracteole (Ross est subgenus within genus Oxyethira and is 1948). Subgenital plate at Orthotrichia cristata distributed in the Holarctic and Oriental regions. (Flint 1968). Bilobed process (Marshall 1979). Segment VIII with long ventral and short dorsal Dorsal process of the inferior appendages (Wells excision, pleuron often with blunt lateral pro- 1979, Malicky & Chantaramongkol 2007). cesses and spines. Dorsum IX often with antero- lateral lobes and/or posterolateral rounded pro- Depositories and abbreviations. Clemson Uni- cesses. Gonopods fused basad. Spiralling para- versity Arthropod Collection (CUAC). Institute of mere present. 27 Oláh & Ito: Synopsis of the Oxyethira flavicornis species group with new Japanese Oxyethira species Oxyethira flavicornis species group Kelley, 1984 sexual selection (Oláh et al. 2012). In this species group we have separated five new species clus- Diagnosis. The flavicornis group of the sub- ters: O. datra, O. ecornuta, O. flavicornis, O. hi- genus Oxyethira has evolved a paramere forming roshima, O. tiunovae. flattened band, that is split into two strands. One strand is usually filiform, the other strand is more Oxyethira datra new species cluster robust and complex. Dorsum IX without anterola- Diagnosis. This species cluster is distinguished teral and posterolateral processes. Aedeagus lack- by the following combination of characters: simp- ing distal processes. Distributed in the Palearctic le apical margin of segment VIII without pro- and Oriental regions, species mentioned, but not duced lobes or processes; simple pair of para- documented from Alaska and USA (Kelley 1985). procts straight in lateral view with capitate or malleolate apex; deep mesal excision on the fused The formation of the parameres is the most gonopod; very complex paramere with anterad reliable character to separate closely related spe- turning spine. Four species belong to this group: cies. The complex strand or arm of the split para- O. datra Oláh, 1989; O. josifovi Kumanski, 1990; mere is very diverse and species specific. This is a O. kakida sp. nov.; O. sichuanensis Yang & direct indication of the intense processes of the Kelley, 1997. Figures 1–4. Oxyethira datra Oláh, 1989, male holotype. 1 = genitalia in left lateral view, 2 = genitalia in dorsal view, 3 = genitalia in ventral view, 4 = phallic organ in left lateral view. 28 Oláh & Ito: Synopsis of the Oxyethira flavicornis species group with new Japanese Oxyethira species Oxyethira datra Oláh, 1989 Oxyethira josifovi Kumanski, 1990 (Figures 1–4) (Figures 5–8) Oxyethira datra Oláh, 1989: 287–288, male, Vietnam. Oxyethira josifovi Kumanski, 1990: 57–59, male, female, Korea. Material examined. Holotype. Vietnam, Cuc Phuong, 400 m, 17.X.1986, light, leg. J. Oláh (1 Material examined. Holotype. Korea, 25 km E male, OPC). Holotype is in a rather disintegrated of Vonsan, 1–3 km from the sea, near Casan condition. Right forewing and hindwing are village, stream and small torrents of the plain, mounted in dry preparation under glass cover; rest 6.X.1978, leg. K. kumanski. According to Y. is in alcohol: body without right wings and abdo- Vidinova and S. Beshkov (Zoological Institute, men is in separate glass vial; abdomen without Bulgarian Academy of Sciences, Sofia, Bulgaria) phallic organ is in separate glass vial. Dissected all the holotypes in the Kumanski’s collection in phallic organ was lost during redrawing proce- the Zoological Institute, Sofia is well preserved, dure! however the holotype of Oxyethira josifovi, the single specimen of this species is lost, probably Remarks. The Holotype was redrawn. The during a loaning procedure. slightly capitate, malleolate and truncate apex of paraproct is similar to Oxyethira josifovi, gonopod Remarks. Paraproct is similar to Oxyethira dat- less deeply excised in ventral view and the para- ra, gonopod more deeply excised and the para- mere is easily distinguishable by its triple coiling mere is easily distinguishable by its single coiling or spiralling and by the fine structure of the or spiralling and by the fine structure of the comp- complex strand. lex strand. Figures 5–8. Oxyethira josifovi Kumanski, 1990, male holotype (adapted from original illustration). 5= genitalia in left lateral view, 6 = genitalia in dorsal view, 7 = genitalia in ventral view, 8 = phallic organ in left lateral view. 29 Oláh & Ito: Synopsis of the Oxyethira flavicornis species group with new Japanese Oxyethira species Oxyethira kakida sp. nov. N 33o44’46”, E 139o18’39”, 3.VIII.2011, leg. T. Nozaki & T. Kagaya (1 male, 1 female; CMB-ZI (Figures 9–12) 146982-146983). Honshu, Yamagata, Kaneyama- machi, Kanayama-gawa, 11.X.1999, leg. A. Oxyethira josifovi Nozaki & Tanida, 2007: 246, Honshu Ohkawa (5 males, 5 females; OPC). Hokkaido, (Shizuoka). Misidentification. Oxyethira datra Malicky & Chantaramongkol, 2007: 1030, Ishikari, Chitose-shi, Bibi, Lake Chitose-ko, 8. Hokkaido (Chitose). Misidentification. VII.2001, light trap, leg. T. Ito & A. Ohkawa (1 male; OPC). Diagnosis. This new species belongs to O. Other specimens. Honshu, Yamagata, Kane- datra species cluster and has periphallic organs of yama-machi, Kanayama-gawa, Araya-bashi, 14. paraproct, gonopods and basal plate of gonopods X.1999, leg. A. Ohkawa (3 males, 5 females; similar to O. sichuanensis Yang & Kelley, 1997 IPC). Hokkaido, Ishikari, Chitose-shi, Bibi, described from China (Sichuan), but differs by Bibigawa River, Bibi-bashi, light trap, 24.IX. having antennal segment 41, not 47; excision on 1999, leg T. Ito (3 males; IPC). Hokkaido, gonopod rounded, not triangular; the complex Kushiro-shi, Akan-cho, Ibeshibetsu-gawa, middle strand of the paramere with blunt apex, not spine- area, 13.IX.1999, light trap, leg. T. Ito (2 males, 3 like; the anterad directed spine on this strand more females; IPC). Hokkaido, Kushiro-shi, Akan-cho, axial, not right-angled. Akan-kohan, Ibeshibetsu, 27.VII.2012, light trap, leg. T. Ito (1 male, 1 female; IPC). Hokkaido, Material examined. Holotype. Japan, Honshu, Shibetsu-cho, Ichani-gawa, Chishine-bashi, light, Shizuoka, Shimizu-cho, Kakida-gawa, N35o06’ 21.VII.1996, leg. T. Ito & A. Ohkawa (2 males, 1 11”, E138o54’10”, 13 m, 11–15.V.2002, Malaise female; IPC). Hokkaido, Obihiro-shi, Izumi-cho, trap, leg T. Nozaki (1 male, CMB-ZI 146972). Tobetsu-gawa, Izumi-bashi, 11.VI.1997, leg. A. Paratypes. Data same as of holotype (4 males, Ohkawa (1 male; IPC). Hokkaido, Shibecha-cho, 5 associated females; CMB-ZI 146973–146981). Kayanuma, Shirarutoroetoro-gawa, Tomi-bashi, Honshu, Tokyo, Fussa-shi, Fussa, Nagata-bashi, 4.IX.2008, leg. T. Ito (1 male; IPC). Figures 9–12. Oxyethira kakida sp. nov. male holotype. 9 = genitalia in left lateral view, 10 = genitalia in dorsal view, 11 = genitalia in ventral view,12 = phallic organ in left lateral view. 30 Oláh & Ito: Synopsis of the Oxyethira flavicornis species group with new Japanese Oxyethira species Description. Male (in alcohol). Light brown. Etymology. The name kakida is a noon in Forewing length 2.3 mm. 3 ocelli present. Anten- apposition, coined from the name of the holotype nal segments 37–42; terminal segment blunt; locality. clothing antennal setae whorled fimbriate. Spur count 034. Segment VII annular with short Oxyethira sichuanensis Yang & Kelley, 1997 ventromesal process. Segment VIII annular; less (Figures 13–16) excised dorsoapicad and more ventroapicad. Male genitalia. Segment IX completely en- Oxyethira sichuanensis Yang, Kelley & Morse, 1997: 92–95, closed within VIII; ventrum longer than dorsum, male, China (Sichuan). ovoid in ventral view with small triangle antero- mesad. Segment X reduced to short membranous Material examined. Paratype. China, Sichuan lobe. Pair of paraproct almost straight in lateral Province, Nanpingxian, Jiouzhaigou, Shuzheng- view with capiate malleolate apex. Gonopods qunhai, 2250 m, 26.VI.1990, leg. J. C. Morse (de- fused basad to the ventrum IX deeply and roundly posited in CUAC). excised and produced into lateral narrow lobes. Basal plate of gonopods forming long bilobed Remarks. In lateral view we have found the process and short setose lobes. Phallic organ with dorsal margin of the complex strand of the paramere encircling shaft once and split into a paramere serrated, not simple as it is indicated on filiform and into a more complex arm; the comp- the holotype drawings. Moreover there is a lex arm serrated and armed with an anterad direct- longitudinal ridge running along and ending in a ed, almost axial spine. tooth on the middle of the strand. Figures 13–16. Oxyethira sichuanensis Yang & Kelley, 1997, male. 13 = genitalia in left lateral view, 14 = genitalia in dorsal view, 15 = genitalia in ventral view, 16 = phallic organ in left lateral view. 31 Oláh & Ito: Synopsis of the Oxyethira flavicornis species group with new Japanese Oxyethira species Oxyethira ecornuta new species cluster (10 males, 5 females; OPC). Hokkaido, Iburi, Tomakamai-shi, Bibigawa River, Uenaebashi Diagnosis. This small species cluster is distin- Bridge, 5.VIII.2010, leg. T. Ito (5 males, 5 guished by the following combination of charac- females; IPC). Hokkaido, Kushiro, Kushiro-shi, ters: simple apical margin of segment VIII with- Akan-cho, Lake Akan-panke-to, 14.IX.1999, out produced lobes or processes; simple pair of sweep, leg. T. Ito (5 males, 5 females; IPC). robust and broad-based paraprocts; wide and Hokkaido, Kushiro, Shibecha-cho, Lake Shira- shallow mesal excision on the fused gonopod; rutoro-ko, 25.VII.2008, light, leg. T. Ito (3 males, simple trifid paramere. Two species belong to this 3 females; IPC). Hokkaido, Ishikari, Sapporo-shi, species cluster: O. acuta Kobayashi, 1977 and O. Nopporo-shinrin-koen Park, 14.VII.2004, light, ecornuta Morton, 1893. leg. Y. Nagayasu & T. Ito (10 males, 10 females; IPC). Oxyethira acuta Kobayashi, 1977 (Figures 17–20) Remarks. We have examined the holotype em- bedded in a permanent glass slide. The pre- Oxyethira acuta Kobayashi, 1977: 6–7, pls. 5–6, male, fe- paration is in good condition, permitting clear male, Hokkaido (Iburi); Ito & Kawamula 1984: 313–317, dorsoventral view of the gonopod and paraproct. pupa, larva, case, life cycle, Hokkaido (Iburi); Ito 2005: 442, 444, larva, case. The fused gonopod and paraprocts on the holo- type preparation is identical to the animals col- Material examined. Holotype. Japan, Lake lected from the locus typicus. These specimens Utonai-ko, Utonai, Tomakomai-shi, Hokkaido, were used for examination and for producing 17.VIII.1976, leg T. ITO (M.5120, deposited in detailed drawings with lateral view. The exa- the form of glass slide specimen CMB-ZI). mined genital structure clearly relates this species Other specimens. Hokkaido, Iburi, Tomaka- to the Oxyethira flavicornis species group and to mai-shi, Lake Utonai-ko, 22.VII.2004, leg. T. Ito the Oxyethira ecornuta species cluster. Figures 17–20. Oxyethira acuta Kobayashi, 1977, male. 17 = genitalia in left lateral view, 18 = genitalia in dorsal view, 19 = genitalia in ventral view, 20 = phallic organ in left lateral view. 32