Geostiba (Sibiota) graveyardensis Pace 1997
Creators: name: Gusarov, Vladimir I.
Publisher: name: Zenodo
Year: 2002
Subjects: Biodiversity
Taxonomy

description: 3. Geostiba (Sibiota) graveyardensis Pace, 1997 (Figs. 72­93)
Geostiba (Ditroposipalia) graveyardensis Pace, 1997: 102.
Material. UNITED STATES: North Carolina: Haywood Co.: 2 specimens, Graveyard Fields at Blue Ridge Parkway, 22 km SE Waynesville, right bank of the river, 35°19.2'N 82°50.7'W, 1550 m, in forest litter by the river, Picea, Betula, Rhododendron (V.I.Gusarov), 20.ix.2001; 48 specimens, Black Balsam Knob Road N of Blue Ridge Parkway, 21 km SSE Waynesville, 35°19.1'N 82°52.6'W, 1800 m, in forest litter, Picea (V.I.Gusarov), 20.ix.2001 (all KSEM and SPSU).
Type locality. UNITED STATES: North Carolina: Haywood Co.: Graveyard Fields at Blue Ridge Parkway (Pace 1997).
Diagnosis. Geostiba graveyardensis can be distinguished from other Nearctic species of Geostiba by having small eyes (temple length to eye length ratio 2.8­3.8), 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, the shape of the aedeagus (Figs. 77­85, 87­93) and the shape of the spermatheca (Fig. 86).
Geostiba graveyardensis is closely related to G. bicarinata but differs in the following: the apex of median lobe in lateral view bent ventrally (Figs. 79­80, 59­60), in ventral view with apical process (Figs. 77­78, 57­58).
Description. Length 1.9­2.3 mm. Brown or dark brown, elytra and apex of abdomen often lighter, 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 2.8­3.8. Antennal article 2 longer than article 3, article 4 slightly transverse, 5­10 transverse, last article longer than 9 and 10 combined (as in Fig. 16).
Pronotum slightly transverse, width 0.41­0.44 mm, width to length ratio 1.1, 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 3­7 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 or four weak and short carinae in front of posterior margin, posterior margin convex (Fig. 72). Male sternum 8 with convex posterior margin (Fig. 73).
Female tergum 8 with convex posterior margin (Fig. 74), posterior margin of sternum 8 concave medially (Figs. 75­76).
Aedeagus as in Figs. 77­85, 87­93. Apex of median lobe in ventral view with apical process (Figs. 77­78), in lateral view bent ventrally (Figs. 79­80), distal diverticula of internal sac with numerous denticles (Figs. 81, 84, 91­92), in ventral view narrow (Figs. 84­85), in lateral view broad (Figs. 91­92).
Spermatheca as in Fig. 86.
Distribution. Known from the Graveyard Ridge and Black Balsam Knob in the Great Balsam Mountains – Pisgah Ridge massif (North Carolina) (Figs. 338, 340).
Natural History. Geostiba graveyardensis was collected by sifting forest litter at altitudes from 1500 m to 1800 m in pure conifer or mixed forest with red spruce (Picea rubens).
description: Published as part of Gusarov, Vladimir I., 2002, A revision of Nearctic species of the genus Geostiba Thomson, 1858 (Coleoptera: Staphylinidae: Aleocharinae), pp. 1-88 in Zootaxa 81 on pages 28-31, DOI: 10.5281/zenodo.155701