Geostiba (Sibiota) appalachigena Gusarov

Gusarov, Vladimir I., 2002, A revision of Nearctic species of the genus Geostiba Thomson, 1858 (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 81, pp. 1-88 : 19-24

1. Geostiba (Sibiota) appalachigena Gusarov , sp. n. ( Figs. 29­50 )

Type material. Holotype ,, UNITED STATES: West Virginia: Pocahontas Co., 19 km NEE Durbin, Hwy. 28, 38°36.65'N 79°37.78'W, 1250 m, forest litter, Picea , Fagus (V.I.Gusarov) , 29.viii.2001 ( KSEM).

Paratypes: UNITED STATES: West Virginia: Pocahontas Co.: 79 specimens, same data as the holotype ( KSEM, AMNH, CNCI, SPSU, FMNH); 5, 2, 9 km SW Durbin, Forest Road 235, Back Allegheny Mt., 38°29.46'N 79°53.85'W, 1430 m, forest litter, Picea , Betula , Fagus (V.I.Gusarov) , 30.viii.2001; 38 specimens, 11 km SW Durbin, Forest Road 235, Back Allegheny Mt., 38°28.46'N 79°54.70'W, 1350 m, forest litter, Betula , Fagus , Picea , Tsuga (V.I.Gusarov) , 30.viii.2001; 4 specimens, 22 km SWW Cass, Hwy. 150, N slope of Red Spruce Knob, 38°20.34'N 80°09.23'W, 1370 m, forest litter, Fagus , Betula (V.I.Gusarov) , 30.viii.2001; 30 specimens, 22 km SWW Cass, Hwy. 150, Black Mountain, 38°16.4'N 80°14.6'W, 1420 m, in forest litter, Picea (V.I.Gusarov) , 30.viii.2001; Pendleton Co.: 11, 10, 9 km SE Sugar Grove, Forest Road 85, 38°28.1'N 79°14.1'W, 1250 m, forest litter, Quercus , Acer , Tsuga , Betula (V.I.Gusarov) , 29.viii.2001; 2, 9 km SE Sugar Grove, County Road 25, 38°28.7'N 79°13.4'W, 1170 m, forest litter, Quercus , Acer , Tsuga , Betula (V.I.Gusarov) , 29.viii.2001; 30 specimens, 18 km NWW Franklin, N slope of Spruce Knob, 38°42.17'N 79°31.73'W, 1500 m, forest litter, Picea , Rhododendron , Acer (V.I.Gusarov) , 29.viii.2001;, 3, 19 km NWW Franklin, Forest Road 104, W slope of Spruce Knob, 38°41.76'N 79°32.36'W, 1450 m, forest litter, Betula , Picea , Tsuga , Sorbus (V.I.Gusarov) , 29.viii.2001 (all in KSEM and SPSU); 2,, Spruce Knob (Peck & Barr), 26.viii.1964 ( FMNH); Tucker Co.: 2, Davis near Blackwater River [39°07.7'N 79°27.8'W], 900 m (L. & N.Herman), 26.vii.1977 ( AMNH);

, “Greenbrier Co., 21 km NE Richwood” [This label is not precise. The point 21 km NE of Richwood is actually at the border between Webster and Pocahontas Counties, at least 11 kilometers from the border of Greenbrier County. It is impossible to give precise coordinates for this point] [38°17'±05'N 80°25'±05'W] (A.Smetana), 13.v.1986 [This specimen bears Lohse’s handwritten label “n. spec. undescribed”] ( CNCI); Virginia: Page Co. / Madison Co.: 10 specimens, 11 km SE Luray, Blue Ridge, below Old Man Mt. summit, 38°35.75'N 78°22.29'W, 1200 m, forest litter, Picea , Quercus, Corylus , Abies (V.I.Gusarov) , 31.viii.2001; Smyth Co. / Grayson Co.: 3, 2, 20 km S Marion, W slope of Mt. Rogers, 36°39.20'N 81°32.99'W, 1500 m, forest litter, Picea , Abies (V.I.Gusarov) , 1.ix.2001 (all in KSEM and SPSU); Maryland: Garett Co.: 5, 5, 2.1 mi. E Keysers Ridge [39°41.6'N 79°12.6'W], 800 m (S.Peck), 18.vi.1968 ( FMNH, KSEM, SPSU); Pennsylvania: Centre Co.: 67 specimens, 6 mi. SE Phillipsburg [40°50.5'N 78°08.0'W], 600 m (S.Peck), 17.vi.1968 ( FMNH, KSEM, SPSU); Clinton Co.: 2, 26 km SEE Lock Haven, 41°03.23'N 77°09.65'W, 350 m, forest litter, Quercus , Tsuga , Pinus (V.I.Gusarov) , 5.iv.1999 ( SPSU); Tioga Co.:,, nr. Arnot [77°07.5'W 41°39.7'N] (W.Muchmore), 18.ix.1969; New Jersey: Morris Co.:, Green Pond, Copperos Mt. [41°01'N 74°28'W], subcortical oak stump (W.Suter), 23.viii.1979;, ditto but 16.viii.1979;, 2, ditto but Green Pond, Pt. Comfort, 23.viii.1979 (all – FMNH); New York: Orange Co.: 6 specimens, 8 km S New Windsor, Black Rock Forest [41°24'N 74°01'W], (V.I.Gusarov), 9.v.1998; 17 specimens, ditto but 23­25.v.1998 (all – SPSU); Ulster Co.: 55 specimens, 5 Mi. SSE Kerhonkson [41°42.5'N 74°15.0'W] (L.Herman), 30.iv.1977 ( AMNH); Chataugua Co.: 3, 2 mi. S Westfield [42°17.4'N 79°34.3'W], leaf litter (L.E.Watrous), 16.vi.1979; Steuben Co.:,, Arkport [42°24'N 77°41'W] (C.Sullivan), 30.iii.1946; Albany Co.: 6, 6, Rensselaerville, Huyck Pres., Ravine near Lincoln Pd. [42°31.7'N 74°09.6'W], birch stump (W.Suter), 18.viii.1974; Tompkins Co.:, McLean [42°33'N 76°18'W], 17.iv.1925; Fulton Co.: 4, 2, 2 mi. N Mayfield, shore of Sacandaga Reservoir [43°08'N 74°14'W] (W.Suter), 25.viii.1974; Hamilton Co.: 2, 7, N Hope, Hopefalls Rd. [43°18'N 74°14'W], along rocky stream (W.Suter), 25.viii.1974; Massachusetts: Middlesex Co.:, 2, Bedford Sta. [42°29'26”N 71°16'36”W] (W.Suter), 11.iv.1977; Rhode Island: ,, Washington Co.: Burlingame St. Park [41°22'N 71°42'W] (L.E.Watrous), 30.xii.1975; New Hampshire: Grafton Co.: 2, Zealand R., 6 mi. SE Twin Mt. [44°13'N 71°29'W], 700 m, fir – spruce – birch forest, berlesing litter (A.Newton & M.Thayer), 5.ix.1975; Carroll Co.:, 4, Ossipee Alspine Cpgd., Rt. 16 [43°48'N 71°10'W] (J.Bengston), 12.viii.1973 (all – FMNH); Maine: Penobscot Co.:, 4, Peaked Mt. near Clifton [44°50'N 68°28'W], 200 m (S.Peck & J.Speel), 18.ix.1967 ( FMNH, SPSU); Wisconsin: Jackson Co.:, 2 mi. S Black River Falls [44°16.0'N 90°50.5'W] (W.Suter), 6.v.1976; CANADA: Québec:, Hull Co., Gatineau Park [45.5°N 76.0°W], (W.S.Suter), 23.v.1979 (all – FMNH);, 5, ditto but King Mt., 24.v.1979 ( FMNH, KSEM, SPSU).

Diagnosis. Geostiba appalachigena can be distinguished from other Nearctic species of Geostiba by having large eyes (temple length to eye length ratio 2.3­2.7), pronotal pubescence of type V, well developed wings, long elytra (pronotum length to elytron length ratio 0.96), the presence of two short parallel carinae in the middle of male abdominal tergum 7 in front of posterior margin, the shape of the aedeagus ( Figs. 34­42, 44­50 ) and the shape of the spermatheca ( Fig. 43 ).

Description. Length 1.9­2.4 mm. Brown or dark brown, elytra and abdominal apex often lighter, antennae brown or yellowish 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 2.3­2.7. Antennal article 2 longer than article 3, article 4 slightly transverse (width to length ratio 1.2), articles 5­10 transverse (ratio 1.5­1.6), last article as long as 9 and 10 combined ( Fig. 16 ); in smaller specimens articles 4­10 more transverse.

Pronotum slightly transverse, width 0.4­0.47 mm, width to length ratio 1.1, wider than head (pronotal width to head width ratio 1.1); microsculpture and puncturation as on head. Pronotal pubescence of type V. Elytra measured from humeral angle longer than pronotum (pronotal length to elytral length ratio 0.96), wider than long (1.2), with fine isodiametric microsculpture and fine, somewhat asperate puncturation, distance between punctures equals 2­3 times their diameter. Elytral suture behind scutellum raised in both sexes. Wings fully developed.

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 3­7 times their diameter. Tergum 7 with white edge.

Male tergum 7 with two medial carinae in front of posterior margin. Male tergum 8 with four small carinae in front of posterior margin, posterior margin slightly convex ( Fig. 29 ), in some specimens with two or four denticles behind the carinae. Male sternum 8 with convex posterior margin ( Fig. 30 ).

Female tergum 8 with slightly convex posterior margin ( Fig. 31 ), sternum 8 with shallow emargination ( Figs. 32­33 ).

Aedeagus as in Figs. 34­42, 44­50 . Apex of median lobe in lateral view bent ventrally and widened apically ( Figs. 36­37 ), distal diverticula of internal sac in ventral view wide ( Figs. 41­42 ).

Spermatheca as in Fig. 43 .

Distribution. Widespread in eastern North America (West Virginia, Virginia, Maryland, Pennsylvania, New Jersey, New York, Massachusetts, Rhode Island, New Hampshire, Maine, Wisconsin, Québec). In the southern extreme of its range (Virginia and West Virginia) it occurs only at higher altitudes (mostly above 1200 m), in the north it occurs at low altitudes (down to 300 m in New York and Pennsylvania) ( Figs. 336­338 ).

Natural History. Geostiba appalachigena lives in forest litter and in the southern portion of its range (in Virginia and West Virginia) it occurs almost exclusively in pure conifer or mixed forest with red spruce ( Picea rubens ) and/or fir ( Abies ).

Etymology: The specific name is derived from the word Appalachian and the Latin verb gigno (to be born, to arise). It refers to the geographical distribution of this species.

Figures

FIGURE 336. Geographical distribution of Nearctic species of Geostiba. The ellipse indicates the area where eleven Southern Appalachian species are distributed.

FIGURE 337. Geographical distribution of Geostiba appalachigena Gusarov, sp. n. The ellipse indicates the area where eleven Southern Appalachian species are distributed.

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.

FIGURES 29 ­ 33. Abdominal segment 8 of Geostiba appalachigena Gusarov, sp. n. (paratypes from Black Mountain, West Virginia). 29 – male tergum 8; 30 – male sternum 8; 31 – female tergum 8; 32 – female sternum 8, 33 – apex of female sternum 8. Scale bar 0.2 mm (29 ­ 32), 0.1 mm (33).

FIGURES 34 ­ 37. Aedeagus of Geostiba appalachigena Gusarov, sp. n. (paratype from Black Mountain, West Virginia). 34 – median lobe, ventral view; 35 – apex of median lobe, ventral view; 36 – median lobe, lateral view; 37 – apex of median lobe, lateral view. Scale bar 0.2 mm (34, 36), 0.1 mm (35, 37).

FIGURES 38 ­ 50. Genitalia of Geostiba appalachigena Gusarov, sp. n. (paratypes from Black Mountain (38, 40 ­ 45, 47 ­ 50) and Back Allegheny Mountain (39, 46), West Virginia). 38 – details of internal sac retracted into median lobe, ventral view; 39 – copulatory piece of internal sac, dorsal view; 40 – medial lamellae of internal sac, ventral view; 41 distal diverticula of everted internal sac, ventral view; 42 – everted internal sac, ventral view; 43 – spermatheca; 44 ­ 45 – details of internal sac retracted into median lobe, lateral view; 46 – copulatory piece of internal sac, lateral view; 47 – medial lamella of internal sac, lateral view; 48 – everted internal sac, lateral view; 49 – right distal diverticulum of everted internal sac, lateral view; 50 – apex of left paramere, side facing median lobe. Scale bar 0.2 mm (38, 42, 44 ­ 45, 48), 0.1 mm (39 ­ 41, 43, 46 ­ 47, 49 ­ 50).

FIGURES 8 ­ 17. Mouthparts of Geostiba circellaris (Gravenhorst) (8, Moscow Region, Russia), G. infirma (Weise) (9, Ivano­Frankovsk Region, Ukraine), G. carteriensis Pace (10 ­ 15, Tennessee), G. appalachigena Gusarov, sp. n. (16, paratype from West Virginia) and G. pluvigena Gusarov, sp. n. (17, paratype from North Carolina). 8 ­ 10, – prementum; 11 – hypopharynx; 12 – left maxilla, ventral view; 13 – left galea, dorsal view; 14 – left lacinia, dorsal view; 15 – mentum; 16 ­ 17 – right antenna. Scale bar 0.1 mm (8 ­ 15), 0.2 mm (16 ­ 17). L – Length of antennal article.