Gnypeta Thomson

Klimaszewski, Jan, Savard, Karine, Pelletier, Georges & Webster, Reginald, 2008, Species review of the genus Gnypeta Thomson from Canada, Alaska and Greenland (Coleoptera, Staphylinidae, Aleocharinae): systematics, bionomics and distribution, ZooKeys 2 (2), pp. 11-84 : 15-22

Genus Gnypeta Thomson

urn:lsid:zoobank.org:act:8297AF32-F721-495A-9B8B-97726265E3DE

Gnypeta Thomson 1858: 33 ; Moore and Legner 1975: 421; Seevers 1978: 83; Blackwelder 1952: 173; Ashe 2001: 363; Smetana 2004: 489. Type species: Homalota labilis Erichson 1839 (= Bolitochara carbonaria Mannerheim 1830 ).

Euliusa Casey 1906: 215 ; Moore and Legner 1975: 421; Seevers 1978: 83; Ashe 2001: 363; Smetana 2004: 489. Synonymized by Blackwelder 1952: 173. Type species: Gnypeta lucens Bernhauer 1905 .

Gnypetoma Casey 1906: 196 ; Moore and Legner 1975: 421; Seevers 1978: 83; Ashe 2001: 363; Smetana 2004: 489. Synonymized by Blackwelder 1952: 173. Type species: Tachyusa baltifera LeConte 1863 .

Diagnosis

Members of this genus may be distinguished by the following combination of characters: tarsi 4, 5, 5-articulated ( Figs 1 , 2 ); body medium sized, length 2.3-3.6 mm, moderately to strongly glossy, integument finely punctate and pubescent, pubescence moderately long and often silky in appearance; head and pronotum distinctly narrower than elytra ( Figs 1-20 ); abdomen as broad as elytra at base or moderately narrower ( Figs 1-20 ), subparallel ( Figs 3-7 ), or broadening apically ( Figs 9 , 18 20 ), first three visible tergites with deep basal impressions bearing coarse punctures but without pronounced longitudinal ridges ( Fig. 1 ); postgenal carinae incomplete or absent ( Seevers 1978); pronotum broadest in apical third or in the middle of the disc, and converging apically and basally ( Fig. 1 ), pubescence distributed postero-laterad from the midline of the disc ( Figs 1-20 ); elytra much broader than both head or pronotum, and often with wavy pubescence pattern on both sides ( Figs 1-20 ); mesoventral process moderately broad, attaining middle of mesocoxae, its apex truncate ( Fig. 2 ); metaventral process broadly rounded ( Fig. 2 ); first visible three tergites with deep basal impressions bearing coarse punctures; legs long and slender; basal article of metatarsus moderately elongate and usually shorter than the two following articles combined ( Fig. 1 ). GENITAL STRUCTURES: median lobe of aedeagus consists of an enlarged, swollen bulbus and short, triangularly produced tubus ( Figs 40, 41 , 49 , 58 , 67, 68 , 76 , 84 , 92 , 100 , 109 , 110 , 118 , 131 , 132 , 140 , 141 , 149 , 157 , 165 , 173 , 182 ), crista apicalis of bulbus large and subtriangular in shape laterally ( Figs 39 , 48 , 57 , 56 ); paramere broad with short apical lobe bearing three long subapical and one short apical macrosetae ( Figs 60 , 77 , 85 , 119 , 142 , 150 ); male tergite 8 truncate, or rarely emarginated apically, its apical

margin smooth or with small 2-4 dents ( Figs 43 , 52 , 61 , 78 , 103 , 112 , 167 ); spermatheca of four types: S-shaped ( Figs 105 , 114 , 153 , 161 ), C-shaped ( Figs 122 , 127-129 , 136 ), hatchet-shaped ( Figs 45 , 54 , 63 , 72 , 80 , 88 , 96 ), or club-shaped ( Figs 169 , 178 , 186, 187 ); capsule tubular with apical part approximately spherical ( Figs 145 , 169 , 178 , 186, 187 ), tubular ( Figs 122 , 127 , 153 , 161 ), or funnel-shaped ( Figs 45 , 54 , 63 , 72 ); stem tubular, elongate, more or less sinuate and moderately swollen basally.

Sternite 8 of male and female with broad space between basal margin and antecostal suture ( Figs 44, 47 , 53, 56 , 62, 65 ). Gnypeta is readily distinguished from most genera of Oxypodini by having 4, 5, 5-articulated tarsi and from closely related Tachyusa by robust body (slender in Tachyusa ), abdomen at base as broad as elytra or only slightly narrower (much narrower in Tachyusa ), lack of distinctive ridges in abdominal tergal impressions, and by less elongate basal article of metatarsus (usually shorter than the

two following articles combined). Ischnopoda Stephens is another related genus to Gnypeta , which differs externally by parallel-sided body, and extremely elongate metatarsus, exceeding 4/5 length of metatibia, and with basal article at least as long as the two following articles combined ( Fig. 1 ). According to Paśnik (2007) the genus Gnypeta is closely related to Tachyusa , Ischnopoderona (Scheerpeltz) and Ischnopoda . The key for these four genera is provided by Paśnik (2007).

Collection and habitat data

Adults are associated with riparian habitats and debris along the margins of marshes, ponds, lakes, and streams ( Ashe 2001). Some Canadian species were found in cold wet moss alongside streams. They may also occur in vegetation and litter along edges of streams, river, and lakes, in grass tussocks on mud flats, in gravel, wooded bogs, beaver lodges, and decaying fungi.

Phylogenetic affiliations

Seevers (1978) classified the genus Gnypeta in the tribe Oxypodini and the subtribe Tachyusae (=Tachyusina Thomson), together with the genera Tachyusa Erichson , Trachyota Casey , Teliusa Casey , Gnypetella Casey , Meronera Sharp , and Brachyusa Mulsant and Rey. He was tempted to consider Tachyusae as a distinct tribe on the grounds of 4, 5, 5-articulated tarsi and the genital features but he was afraid that this arrangement would obscure the relationship of Gnypeta to some related oxypodine genera. Bernhauer and Scheerpeltz (1926) did not separate genera of Tachyusina from Falagriini and grouped them together in the subtribe Falagriae of the tribe Myrmedoniini Ganglbauer. Lohse (1974) placed Gnypeta together with Falagria Leach , Cordalia Jacobs , Myrmecopora Saulcy and allied genera of the Falagriini. We agree with Seevers (1978) that grouping Tachyusae and Falagriae together, mainly on the grounds of 4, 5, 5-articulated tarsi and some superficial external similarities, was artificial and unwarranted. According to Seevers (1978) and confirmed here by us, the Tachyusae lack the following specialized features of the Falagriini: paramere with codylite velum separated from the paramerite velum; pronotum much narrower at base than apex and with distinct (at least one) median sulcus (sometimes two lateral sulci present); peritremes enlarged, and contiguous with or fused to elongate prosternum; procoxal cavities closed by peritremes, prosternum and inflexed hypomera. In addition the Falagriini have a basal abdominal impression bearing a median ridge, a very distinct shape of the median lobe of the aedeagus (ovoid bulbus and tubular broad tubus), small and narrowly elongate crista apicalis of bulbus, extremely long and coiled flagellum of the internal sac of the median lobe, and the spermatheca is of a different type with a small spherical capsule connected to a thin stem ( Figs 165, 166, 169 in Klimaszewski and Winchester 2002). For diagnostic features of Tachyusina, see Seevers (1978). In his worldwide treatment of Ischnopoda Stephens, Paśnik (2006b) considered this genus to be closely related to Tachyusa and Gnypeta . Based on a comparative study of mouthparts and the body chaetotaxy, Yosii and Sawada (1976) suggested a restricted concept of Tachyusa -related genera and placed Tachyusa together with Gnypeta , and Dacrila Mulsant and Rey in the Tachyusa series of the Athetae. Their tribal affiliation of the Tachyusa -related genera with athetines is strongly questionable because of the differences in the genital features of the two groups e.g., lack of the “athetine bridge” in the median lobe of the aedeagus in genera of Tachyusini . Lohse (1989) excluded Tachyusa , Gnypeta , and Dasygnypeta Lohse from Falagriini and transferred them together with Brachyusa and Dacrila to the separate tribe Tachyusini . Paśnik (2006b), in his revision of the world species of Tachyusa , did not provide his view on the higher classification of Tachyusa -related genera but did not contradict the classification proposed by Lohse (1989). Paśnik (2007) published a revision of the African genus Ischnopoderona (Scheerpeltz) , with cladistic analysis of the species. He included there the outgroup taxa of the genera Gnypeta , Ischnopoda , and Tachyusa . On his single most parsimonious cladogram the Ischnopoderona branched off as a sisiter taxon of Tachyusa and both of them combined formed a sister taxon of Gnypeta . The Ischnopoderona was the most basal branch of this tree.We believe that more research is needed before tribal classification of this group becomes clear and stable.

Figures

Fig. 1. Gnypeta nigrella (LeConte), in dorsal view. Scale = 1 mm.

Fig. 2. Gnypeta nigrella (LeConte), in ventral view. Scale = 1 mm.

Figs 3-8. Gnypeta species: 3, G. ashei; 4, G. brincki; 5, G. atrolucens; 6, G. sellmani: 7, G. dentata; and 8, G. groenlandica. Scale = 1 mm

Figs 9-14. Gnypeta species: 9, G. brevicornis; 10, G. caerulea; 11, G. lohsei; 12, G. crebrepunctata; 13, G. manitobae [apical part of abdomen removed]; 14, G. uteana. Scale = 1 mm

Figs 15-20. Gnypeta species: 15, G. carbonaria; 16, G. helenae; 17, G. canadensis; 18, G. nigrella; 19, G. saccharina; and 20, G. minuta [18-20, apical part of abdomen removed]. Scale = 1 mm

Figs 39-47. Genital structures of Gnypeta ashei: 39, median lobe of the aedeagus in lateral view, 40, dorsal view, 41, ventral view; 42, paramere; 43, male tergite 8; 44, male sternite 8; 45, spermatheca; 46, female tergite 8; 47, female sternite 8.

Figs 48-56. Genital structures of Gnypeta brincki: 48, median lobe of the aedeagus in lateral view, 49, dorsal view, 50, apical part of median lobe in ventral view; 51, paramere; 52, male tergite 8; 53, male sternite 8; 54, spermatheca; 55, female tergite 8; 56, female sternite 8.

Figs 57-65. Genital structures of Gnypeta atrolucens: 57, median lobe of the aedeagus in lateral view, 58, dorsal view, 59, apical part of median lobe in ventral view; 60, paramere; 61, male tergite 8; 62, male sternite 8; 63, spermatheca; 64, female tergite 8; 65, female sternite 8.

Figs 66-74. Genital structures of Gnypeta sellmani: 66, median lobe of the aedeagus in lateral view, 67, dorsal view, 68, apical part of median lobe in ventral view; 69, paramere; 70, male tergite 8; 71, male sternite 8; 72, spermatheca; 73, female tergite 8; 74, female sternite 8.

Figs 75-82. Genital structures of Gnypeta dentata: 75, median lobe of the aedeagus in lateral view, 76, dorsal view; 77, paramere; 78, male tergite 8; 79, male sternite 8; 80, spermatheca; 81, female tergite 8; 82, female sternite 8.

Figs 83-90. Genital structures of Gnypeta groenlandica: 83, median lobe of the aedeagus in lateral view, 84, dorsal view; 85, paramere; 86, male tergite 8; 87, male sternite 8; 88, spermatheca; 89, female tergite 8; 90, female sternite 8.

Figs 91-98. Genital structures of Gnypeta brevicornis: 91, median lobe of the aedeagus in lateral view, 92, ventral view; 93, paramere; 94, male tergite 8; 95, male sternite 8; 96, spermatheca; 97, female tergite 8; 98, female sternite 8.

Fig. 192. Collection localities in Canada of G. atrolucens and G. nigrella.

Fig. 194. Collection localities in Canada of G. crebrepunctata, G. dentata, and G. helenae.

Fig. 195. Collection localities in Canada and Alaska of G. groenlandica.

Fig. 196. Collection localities in Canada of G. brevicornis and G. uteana.

Fig. 197. Collection localities in Canada and Alaska of G. caerulea.

Fig. 198. Collection localities in Canada and Alaska of G. lohsei and G. canadiensis.

Fig. 199. Collection localities in Canada and Alaska of G. carbonaria and G. saccharina.

Figs 99-107. Genital structures of Gnypeta brincki: 99, median lobe of the aedeagus in lateral view, 100, dorsal view, 101, apical part of median lobe in ventral view; 102, paramere; 103, male tergite 8; 104, male sternite 8; 105, spermatheca; 106, female tergite 8; 107, female sternite 8.

Figs 108-116. Genital structures of Gnypeta lohsei: 108, median lobe of the aedeagus in lateral view, 109, dorsal view, 110, apical part of median lobe in ventral view; 111, paramere; 112, male tergite 8; 113, male sternite 8; 114, spermatheca; 115, female tergite 8; 116, female sternite 8.

Figs 117-124. Genital structures of Gnypeta crebrepunctata: 117, median lobe of the aedeagus in lateral view, 118, dorsal view; 119, paramere; 120, male tergite 8; 121, male sternite 8; 122, spermatheca; 123, female tergite 8; 124, female sternite 8.

Figs 130-138. Genital structures of Gnypeta uteana: 130, median lobe of the aedeagus in lateral view, 131, dorsal view, 132, ventral view; 133, paramere; 134, male tergite 8; 135, male sternite 8; 136, spermatheca; 137, female tergite 8; 138, female sternite 8.

Figs 139-147. Genital structures of Gnypeta brincki: 139, median lobe of the aedeagus in lateral view, 140, dorsal view, 141, apical part of median lobe in ventral view; 142, paramere; 143, male tergite 8; 144, male sternite 8; 145, spermatheca; 146, female tergite 8; 147, female sternite 8.

Figs 148-155. Genital structures of Gnypeta helenae: 148, median lobe of the aedeagus in lateral view, 149, dorsal view; 150, paramere; 151, male tergite 8; 152, male sternite 8; 153, spermatheca; 154, female tergite 8; 155, female sternite 8.

Figs 156-163. Genital structures of Gnypeta canadensis: 156, median lobe of the aedeagus in lateral view, 157, ventral view; 158, paramere; 159, male tergite 8; 160, male sternite 8; 161, spermatheca; 162, female tergite 8; 163, female sternite 8.

Figs 164-171. Genital structures of Gnypeta nigrella: 164, median lobe of the aedeagus in lateral view, 165, dorsal view; 166, paramere; 167, male tergite 8; 168, male sternite 8; 169, spermatheca; 170, female tergite 8; 171, female sternite 8.

Figs 172-180. Genital structures of Gnypeta saccharina: 172, median lobe of the aedeagus in lateral view, 173, dorsal view, 174, apical part of median lobe in ventral view; 175, paramere; 176, male tergite 8; 177, male sternite 8; 178, spermatheca; 179, female tergite 8; 180, female sternite 8.

Figs 181-189. Genital structures of Gnypeta minuta: 181, median lobe of the aedeagus in lateral view, 182, dorsal view; 183, paramere; 184, male tergite 8; 185, male sternite 8; 186, 187, spermatheca; 188, female tergite 8; 189, female sternite 8.

Figs 125-129. Genital structures of Gnypeta manitobae (lectotype): 125, female tergite 8; 126, female sternite 8; 127-129, spermatheca.