Geostiba (Sibiota) alticola Lohse & Smetana, 1988

Gusarov, Vladimir I., 2002, A revision of Nearctic species of the genus Geostiba Thomson, 1858 (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 81, pp. 1-88 : 60-64

11. Geostiba (Sibiota) alticola Lohse & Smetana, 1988 ( Figs. 262­283 )

Geostiba alticola Lohse & Smetana, 1988: 271 .

Geostiba bicarinata: Lohse & Smetana, 1988: 273 , ex parte (misidentification). Geostiba (Lioglutosipalia) carteriensis: Pace, 1997: 106 , ex parte (misidentification).

Type material. Holotype ,, UNITED STATES: North Carolina: Buncombe Co.: Blue Ridge Parkway, Grey Beard Mountain View [35°42'37"N 82°21'51"W], 1700 m (A.Smetana), 4.vi.1986 ( CNCI); allotype,, North Carolina: Yancey Co.: Mt. Mitchell, 2000­2036m (A.Smetana), 4.vi.1986; paratypes: 3, 3, the same data as the holotype; 4,, the same data as the allotype (all – CNCI).

Additional material. UNITED STATES: North Carolina: McDowell Co.[?]: 27 specimens, Mt. Mitchell, Blue Ridge Parkway, 1700 m [this label is not precise; Mt. Mitchell is in Yancey County at least 5 kilometers from Blue Ridge Parkway; it is not possible to find coordinates for this sample] (J.S. & A.K.Ashe), sifted conifer litter, 2.viii.1991 ( KSEM); 2, ditto but 1676­1920 m ( KSEM); Buncombe Co:, 2, Craggy Dome, [35°42'20"N 82°22'00"W] (T.C.Barr, M.C.Bowling), 22.vii.1960 ( AMNH);, Blue Ridge Parkway, 16 km E Weaverville, Bearpen Knob, 35°41.91’N 82°23.05’W, 1740 m, mountain meadows, in dead grass under Rhododendron and Sorbus (V.I.Gusarov) , 25.vi.2001 ( SPSU); 12 specimens, ditto but 35°41.91’­42.02’N 82°23.05­ 22.83’W, 1700 m, in forest litter, Acer , Betula , Rhododendron ; 18 specimens, 15 km E Weaverville, Pisgah National Forest, Bearpen Gap, 35°41.98’N 82°23.52’W, 1600 m, in forest litter, Picea , Fagus , Betula (V.I.Gusarov) , 25.vi.2001; 8 specimens, Blue Ridge Parkway, 18 km E Weaverville, 35º42.78’N 82º21.89’W, 1720 m, in forest litter, Picea , Betula (V.I.Gusarov) , 25.vi.2001 (all – KSEM and SPSU); Yancey Co.:, Black Mountains, vii; 2, 4, Mt. Mitchell, 1400­1800 m (E.D.Quirsfeld), 17­24.vi.1939 (all – AMNH); 141 specimens, Mt.Mitchell (W.Suter), 12.vi.1973; 73 specimens, Mt.Mitchell near Blue Ridge Parkway, 1500 m (W.Suter), 17.vi.1973; 118 specimens, Mt.Mitchell, 1700 m (S.Peck), 9.iv.1967;, Mt.Mitchell, balsam fir litter above spring near summit (W.Suter), 31.v1973 (all – FMNH); 20 specimens, 16 km S Burnsville, Mt.Mitchell State Park, N slope of Mt. Mitchell, 35°46.19’N 82°15.97’W, 1920 m, in forest litter, Abies (V.I.Gusarov) , 25.vi.2001; 15 specimens, 21 km S Burnsville, Road 128, 35°43.42’N 82°16.97’W, 1600 m, in forest litter, Picea , Abies , Betula , Acer (V.I.Gusarov) , 25.vi.2001 ,, ditto but 35°43.32’N 82°17.29’W, 3.vi.2001; 15 specimens, Road 128, 19 km S Burnsville, Mt.Mitchell State Park, 35°44.71’N 82°16.83’W, 1800 m, in forest litter, Picea , Betula (V.I.Gusarov) , 25.vi.2001; 6 specimens, Road 128, 17 km S Burnsville, Mt.Mitchell, 35°45.92’N 82°16.26’W, 1920 m, in forest litter, Abies (V.I.Gusarov) , 25.vi.2001;, 17 km S Burnsville, Mt.Mitchell, near summit, 35°45.58’N 82°15.51’W, 2050 m, in forest litter, Picea rubens , Abies fraseri (V.I.Gusarov) , 3.vi.2001; Yancey Co. / Buncombe Co.: 19 specimens, 19 km S Burnsville, Blue Ridge Parkway, Balsam Gap overlook, 35°44.86’N 82°19.94’W, 1650 m, in forest litter, Picea , Abies , Betula , Acer (V.I.Gusarov) , 25.vi.2001 (all – KSEM and SPSU).

One of the paratypes of G. bicarinata listed by Lohse and Smetana (1988: 275) (not found in CNCI) must also belong to G. alticola (1 specimen, Buncombe Co.: base of Mt. Mitchell at Blue Ridge Parkway, about 1650 m (A.Smetana), 3.vi.1986). Two of the paratypes of G. carteriensis listed by Pace (1997: 106) (not examined) must also belong to G. alticola (2, Yancey Co.: Mt. Mitchell, 1800 m (P.Debs), 17.iv.1974). These assertions are based on the results of my extensive collecting efforts which demonstrated that G. bicarinata is restricted to the Great Balsam Mountains – Pisgah Ridge massif, G. carteriensis is restricted to the Bald Mountains and the Roan Mountain massif while G. alticola is the only species of Geostiba which occurs in the Great Craggy Mountains ­ Black Mountains massif.

Mislabeled material., United States: Alabama: Blount Co.: 1 mi. SE Blount Springs (S.Peck), 5.iv.1967 ( FMNH). This male is identical with the types of G. alticola and other specimens from the Black Mountains massif in all external characters and in genitalia. Geostiba alticola is a wingless species restricted to the Great Craggy Mountains ­ Black Mountains massif in the Southern Appalachians and occurs only above 1500 m. The altitude of the locality in Alabama is about 200 m. I consider the Alabama specimen to have been mislabeled. It is worth noting that four days later, on April 9, 1967, Stewart Peck collected a long series of G. alticola on the Mount Mitchell. Apparently one specimen was misplaced and mixed up with a sample from Alabama. Geostiba alticola does not occur in Alabama.

Diagnosis. Geostiba alticola can be distinguished from other Nearctic species of Geostiba by having small eyes (temple length to eye length ratio 3.8­5.0), pronotal pubescence of type V or VI, directed posteriorly in a wide medial zone (wider in males), not just along the midline, reduced wings, short elytra (pronotum length to elytron length ratio 1.3), the absence of carinae on abdominal tergum 7, the shape of the aedeagus ( Figs. 267­275, 277­ 283 ) and the shape of the spermatheca ( Fig. 276 ).

Geostiba alticola differs from closely related G. carteriensis in having longer and more narrow (in lateral view) apex of the median lobe of aedeagus ( Figs. 269­270 , 292­ 293 ) and the lateral sides of the apex less convex (in ventral view) ( Figs. 267­268 , 289­ 291 ).

Description. Length 1.9­2.4 mm. Body uniformly light brown, in some specimens abdominal segments 3­6 darker. Body parallel­sided.

Head as wide as long, surface on disk with fine isodiametric microsculpture, puncturation very fine, distance between punctures equal to 2­4 times their diameter. Temple length to eye length ratio 3.8­5.0. Antennal article 2 longer than article 3, article 4 subquadrate, 5­10 transverse, last article as long as 9 and 10 combined.

Pronotum as wide as long, width 0.39­0.44 mm, wider than head (pronotal width to head width ratio 1.1); microsculpture and puncturation as on head; pronotal pubescence of type V or VI (directed posteriorly in wide medial zone (wider in males), not just along midline). 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 very slightly raised. 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 2­5 times their diameter. Tergum 7 without white edge.

Males with stronger impression on disc of head and along midline of pronotum than females. Male tergum 7 without carinae. Posterior margin of male tergum 8 slightly convex ( Fig. 262 ). Posterior margin of male sternum 8 convex ( Fig. 263 ).

Posterior margin of female tergum 8 convex ( Fig. 264 ). Posterior margin of female sternum 8 concave medially ( Figs. 265­266 ).

Aedeagus as in Figs. 267­275, 277­283 . Apex of median lobe in lateral view strait ( Figs. 269­270 ), in ventral view apex outline emarginate basally ( Figs. 267­268 ). Distal diverticula of internal sac narrow ( Figs. 274­275, 281­282 ).

Spermatheca as in Fig. 276 .

Distribution. Known only from the Great Craggy Mountains – Black Mountains massif ( Figs. 338­339 ).

Natural History. Geostiba alticola was collected in forest litter at altitudes above 1500 m in leaf litter mostly in pure conifer or mixed forest with red spruce ( Picea rubens ) and/or Fraser’s fir ( Abies fraseri ).

Figures

FIGURE 338. Geographical distribution of twelve species of Geostiba in the Southern Appalachians. Isohypses 1200 m and 1500 m are shown. Areas above 1500 m are solid black.

FIGURE 339. Detailed geographical distribution of Geostiba alticola Lohse & Smetana (11) and G. carteriensis Pace (12) in the Southern Appalachians. Isohypses 1200 m and 1500 m are shown. Areas above 1500 m are solid black.

FIGURES 262 ­ 266. Abdominal segment 8 of Geostiba alticola Lohse & Smetana (N slope of Mt. Mitchell (262 ­ 263) and 21 km S Burnsville (264 ­ 266), North Carolina). 262 – male tergum 8; 263 – male sternum 8; 264 – female tergum 8; 265 – female sternum 8, 266 – apex of female sternum 8. Scale bar 0.2 mm (262 ­ 265), 0.1 mm (266).

FIGURES 267 ­ 270. Aedeagus of Geostiba alticola Lohse & Smetana (N slope of Mt. Mitchell, North Carolina). 267 – median lobe, ventral view; 268 – apex of median lobe, ventral view; 269 – median lobe, lateral view; 270 – apex of median lobe, lateral view. Scale bar 0.2 mm (267, 269), 0.1 mm (268, 270).

FIGURES 271 ­ 283. Genitalia of Geostiba alticola Lohse & Smetana (Mt. Mitchell (272 ­ 275, 278 ­ 282), N slope of Mt. Mitchell (271, 277, 283) and 21 km S Burnsville (276), North Carolina). 271 – details of internal sac retracted into median lobe, ventral view; 272 – copulatory piece of internal sac, dorsal view; 273 – medial lamellae of internal sac, ventral view; 274 – distal diverticula of everted internal sac, ventral view; 275 – everted internal sac, ventral view; 276 – spermatheca; 277 ­ 278 – details of internal sac retracted into median lobe, lateral view; 279 – copulatory piece of internal sac, lateral view; 280 – medial lamella of internal sac, lateral view; 281 – everted internal sac, lateral view; 282 – right distal diverticulum of everted internal sac, lateral view; 283 – apex of left paramere, side facing median lobe. Scale bar 0.2 mm (271, 275, 277 ­ 278, 281), 0.1 mm (272 ­ 274, 276, 279 ­ 280, 282 ­ 283).

FIGURES 289 ­ 293. Aedeagus of Geostiba carteriensis Pace (Big Bald (289) and Roan Road Pass (290 ­ 293), Tennessee / North Carolina). 289 ­ 290 – median lobe, ventral view; 291 – apex of median lobe, ventral view; 292 – median lobe, lateral view; 293 – apex of median lobe, lateral view. Scale bar 0.2 mm (289 ­ 290, 292), 0.1 mm (291, 293).