Geostiba (Sibiota) nebuligena Gusarov

Gusarov, Vladimir I., 2002, A revision of Nearctic species of the genus Geostiba Thomson, 1858 (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 81, pp. 1-88 : 40-44

publication ID

https://doi.org/ 10.5281/zenodo.155701

DOI

https://doi.org/10.5281/zenodo.6277571

persistent identifier

https://treatment.plazi.org/id/5B50E916-FFB9-3908-4D2D-FEA7FE0CFC04

treatment provided by

Plazi

scientific name

Geostiba (Sibiota) nebuligena Gusarov
status

 

6. Geostiba (Sibiota) nebuligena Gusarov View in CoL , sp. n. ( Figs. 146­168 View FIGURES 146 ­ 151 View FIGURES 152 ­ 156 View FIGURES 157 ­ 168 )

Type material. Holotype ,, UNITED STATES: Tennessee / North Carolina: Sevier Co. / Swain Co.: Appalachian Scenic Trail W of Clingmans Dome, 16 km S Gatlinburg, 35°33.93'N 83°31.76'W, 1800 m, in forest litter, Picea , Abies , Acer , Fraxinus , Oxalis (V.I.Gusarov) , 22.vi.2001 ( KSEM).

Paratypes: UNITED STATES: Tennessee / North Carolina: Sevier Co. / Swain Co.: 49 specimens, same data as the holotype ( KSEM, AMNH, CNCI, SPSU, FMNH); 27 specimens, Clingmans Dome [35°33'46"N 83°29'55"W] (J.S. & A.K.Ashe), 31.vii.1991 ( KSEM); 2, ditto but 2000 m, Fraser Fir – Red Spruce forest (J.Bengston), 7.vii.1974 ( FMNH); 83 specimens, Clingmans Dome Road, 14 km SSE Gatlinburg, 35°35.46'N 83°28.28'W, 1800 m, in forest litter, Picea rubens , Abies fraseri , Oxalis , Rubus (V.I.Gusarov) , 1.vi.2001 ( KSEM, SPSU); 19 specimens, Appalachian National Scenic Trail, W of Clingmans Dome, 16 km S Gatlinburg, 35°33.88'N 83°31.41'W, 1930 m, in forest litter, Picea , Abies , Betula , Oxalis (V.I.Gusarov) , 22.vi.2001 ( KSEM, SPSU); 2,, trail to Mt. Le Conte from Newfound Gap (W.S.Suter), 29.v.1982 ( KSEM); 24 specimens, 0.5 km E Newfound Gap, 13 km SE Gatlinburg, 35°36.44'N 83°25.37'W, 1650 m, in forest litter, Picea rubens , Oxalis , Vaccinium (V.I.Gusarov) , 1.vi.2001 ( KSEM, SPSU); Tennessee: Sevier Co.: 13 specimens, Highway 441 & 71, 13 km SE Gatlinburg, 35°37.3'N 83°26.3'W, 1300 m, in forest litter, Rhododendron , Tsuga , Betula (V.I.Gusarov) , 22.vi.2001 ( SPSU);,, descending the Chimney Tops, 9­10 km SSE Gatlinburg, 35°37.6­38.2'N 83°28.2'W, 1040­1200 m, in forest litter, Tsuga , Acer , Rhododendron (V.I.Gusarov) , 22.vi.2001 ( SPSU);, Great Smokey Mts. National Park (W.Shear & F.Coyle), 24.x.1969 ( FMNH); 18 specimens, Mt. Le Conte, half way up [35°38.5'N 83°26.8'W], deciduous forest, dry leaf litter near log (Lackey), 5.viii.1956 ( FMNH, SPSU); North Carolina: Swain Co.:,, S slope of Clingmans Dome, 19 km NW Cherokee, 35°33.66'N 83°29.9'W, 2000 m, in forest litter, under young Abies trees (V.I.Gusarov), 1.vi.2001 ( SPSU);

Mislabeled material. 14 specimens, UNITED STATES: Michigan, Gogebic Co., Ottawa National Forest, Sylvania Tract, litter & mycelium (J.Wagner), 13.viii.1977 ( KSEM). These specimens are identical with the types of G. nebuligena in all external characters and in genitalia. G. nebuligena is a wingless species restricted to the Great Smoky Mountains massif in the Southern Appalachians, and it is impossible for this species to occur also in Michigan, the area which was covered by ice sheet in Pleistocene. I consider these 14 specimens as mislabeled and exclude them from the types series, because their origin is unknown. Geostiba nebuligena does not occur in Michigan.

Diagnosis. Geostiba nebuligena can be distinguished from other Nearctic species of Geostiba by having small eyes (temple length to eye length ratio 2.9­4.0), pronotal pubescence of type V, reduced wings, short elytra (pronotum length to elytron length ratio 1.3), the presence of two short parallel carinae in the middle of abdominal tergum 7 in front of posterior margin and the shape of the aedeagus ( Figs. 152­161, 163­168 View FIGURES 152 ­ 156 View FIGURES 157 ­ 168 ) and the shape of the spermatheca ( Fig. 162 View FIGURES 157 ­ 168 ).

Geostiba nebuligena differs from closely related G. nimbicola , G. pluvigena and G. crepusculigena in having apex of median lobe with strong apical denticle (in lateral view) ( Figs. 155­156 View FIGURES 152 ­ 156 , 102­103 View FIGURES 100 ­ 107 , 128­129 View FIGURES 126 ­ 133 , 176­177 View FIGURES 174 ­ 177 ).

Description. Length 1.6­1.9 mm. Light brown to brown, antennae light brown, legs and mouthparts brownish yellow. Body parallel­sided.

Head as wide as long, surface on disk with fine isodiametric microsculpture, puncturation very fine, distance between punctures equal to 3­4 times their diameter. Temple length to eye length ratio 2.9­4.0. Antennal article 2 longer than article 3, article 4 transverse (width to length ratio 1.6), articles 5­10 strongly transverse, last article as long as 9 and 10 combined (as in Fig. 17 View FIGURES 8 ­ 17 ).

Pronotum as wide as long, width 0.37­0.40 mm, wider than head (pronotal width to head width ratio 1.2); microsculpture and puncturation as on head. Pronotal pubescence of type V. Elytra measured from humeral angle shorter than pronotum (pronotal length to elytral length ratio 1.3), wider than long (1.5), with fine isodiametric microsculpture and fine asperate puncturation, distance between punctures equals 2­3 times their diameter.

Elytral suture behind scutellum slightly raised in both sexes. Wings reduced to short vestiges, shorter than elytra.

Abdominal terga with fine microsculpture of transverse meshes, with fine and sparse puncturation, puncturation becoming finer towards abdomen apex, on terga 3­5 distance between punctures equals 3­6 times their diameter. Tergum 7 without white edge.

Male tergum 7 with two medial carinae in front of posterior margin. Male tergum 8 with two weak and short carinae in front of posterior margin, posterior margin convex ( Fig. 146 View FIGURES 146 ­ 151 ). Male sternum 8 with convex posterior margin ( Fig. 147 View FIGURES 146 ­ 151 ).

Female tergum 8 with convex posterior margin ( Fig. 148 View FIGURES 146 ­ 151 ), sternum 8 with weakly emarginate posterior margin ( Figs. 149­150 View FIGURES 146 ­ 151 ).

Aedeagus as in Figs. 152­161, 163­168 View FIGURES 152 ­ 156 View FIGURES 157 ­ 168 . Apex of median lobe in ventral view narrow, its outline doubly emarginate apically ( Figs. 152­154 View FIGURES 152 ­ 156 ), in lateral view strait, with strong apical denticle ventrally ( Figs. 155­156 View FIGURES 152 ­ 156 ), distal diverticula of internal sac in ventral view broad ( Figs. 160­161 View FIGURES 157 ­ 168 ).

Spermatheca as in Fig. 162 View FIGURES 157 ­ 168 .

Distribution. Known from the Great Smoky Mountains massif (Tennessee and North Carolina) ( Figs. 338 View FIGURE 338 , 340 View FIGURE 340 ).

Natural History. Geostiba nebuligena was collected at altitudes above 1000 m in leaf litter in pure conifer or mixed forest with red spruce ( Picea rubens ), Fraser’s fir ( Abies fraseri ) or hemlock.

Etymology. The specific name is derived from the Latin noun nebula (mist, fog) and the verb gigno (to be born, to arise). It refers to fogs in the Great Smoky Mountains where the species occurs.

AMNH

American Museum of Natural History

CNCI

Canadian National Collection Insects

FMNH

Field Museum of Natural History

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Staphylinidae

Genus

Geostiba

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