Geostiba (Sibiota) nimbicola 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: 31-35

publication ID

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

publication LSID

lsid:zoobank.org:pub:B36587A1-248A-4194-8424-46C9BBA15606

persistent identifier

http://treatment.plazi.org/id/5B50E916-FF80-3901-4D2D-F97FFDFEFD4C

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scientific name

Geostiba (Sibiota) nimbicola Lohse & Smetana, 1988
status

 

4. Geostiba (Sibiota) nimbicola Lohse & Smetana, 1988  ( Figs. 94­119View FIGURES 94 ­ 99View FIGURES 100 ­ 107View FIGURES 108 ­ 119)

Geostiba nimbicola Lohse & Smetana, 1988: 275  .

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

Type material. Holotype ,, UNITED STATES: Tennessee / North Carolina: Sevier Co. / Swain Co.: Great Smoky Mountains National Park, Clingmans Dome [35 ° 33 ' 46 "N 83 ° 29 ' 55 "W], 1950­2020 m, (A.Smetana) 2.vi. 1986 ( CNCI); allotype,, same data as the holotype; paratypes: 3 ,, ditto (all – CNCI).

Additional material. UNITED STATES: Tennessee / North Carolina: Sevier Co. / Swain Co.: (with missing abdomen), same data as the holotype ( CNCI); 2, 3, ditto but (W.S.Suter) 29.v. 1982 ( KSEM); Tennessee: Sevier Co.:, 4, Great Smoky Mts. National Park, Ramsey Cascade, [35 ° 42 ' 30 "N 83 ° 18 '02"W], moss on rock (Lackey), 21.vii. 1956 ( FMNH, SPSU); North Carolina: Haywood Co.: 15 specimens, Mount Sterling Ridge, 26 km NNW Waynesville, 35 ° 41.9 'N 83 °07.5'W, 1700 m, in forest litter, Picea  , Abies  , Quercus  , Betula (V.I.Gusarov)  , 22.ix. 2001; 14 specimens, ditto but, 35 ° 42.1 'N 83 °06.8'W, 1550 m, Picea  , Rhododendron  , Betula  (all – KSEM and SPSU)

One of the paratypes of G. bicarinata  listed by Lohse & Smetana (1988: 275) (not found in CNCI) must also belong to G. nimbicola  (1 specimen, Great Smoky Mountains National Park, Clingmans Dome, 1950­2020 m, (A.Smetana) 2.vi. 1986). This assertion is based on the results of my extensive collecting efforts which demonstrated that G. bicarinata  is restricted to the Great Balsam Mountains – Pisgah Ridge massif.

Diagnosis. Geostiba nimbicola  can be distinguished from other Nearctic species of Geostiba  by having small eyes (temple length to eye length ratio 3.0­4.0), 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, the shape of the aedeagus ( Figs. 100­112, 114 ­ 119View FIGURES 100 ­ 107View FIGURES 108 ­ 119) and the shape of the spermatheca ( Fig. 113View FIGURES 108 ­ 119).

Geostiba nimbicola  is closely related to G. pluvigena  , G. nebuligena  , and G. crepusculigena  . Geostiba nimbicola  differs from G. pluvigena  in having longer and more narrow apex of median lobe without apical denticle (in lateral view) ( Figs. 100­107View FIGURES 100 ­ 107, 126­ 133View FIGURES 126 ­ 133); from G. nebuligena  in having deeper apical emargination in female sternum 8 ( Figs. 97­ 98View FIGURES 94 ­ 99, 149­ 150View FIGURES 146 ­ 151), longer and more narrow apex of median lobe without apical denticle (in lateral view) ( Figs. 100­107View FIGURES 100 ­ 107, 152­ 156View FIGURES 152 ­ 156); from G. crepusculigena  in lacking obtuse projection on the ventral side of the apex of median lobe ( Figs. 102­103View FIGURES 100 ­ 107, 176­ 177View FIGURES 174 ­ 177).

Description. Length 1.6 ­2.0 mm. Light brown or brown, apex of abdomen often lighter, antennae brownish yellow or 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 3.0­4.0. 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. 17View FIGURES 8 ­ 17).

Pronotum as wide as long, width 0.37­0.40 mm, 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 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 weak and short carinae in front of posterior margin, posterior margin convex ( Fig. 94View FIGURES 94 ­ 99). Male sternum 8 with convex posterior margin ( Fig. 95View FIGURES 94 ­ 99).

Female tergum 8 with convex posterior margin ( Fig. 96View FIGURES 94 ­ 99), sternum 8 with emarginate posterior margin ( Figs. 97­98View FIGURES 94 ­ 99).

Aedeagus as in Figs. 100­112, 114 ­ 119View FIGURES 100 ­ 107View FIGURES 108 ­ 119. Apex of median lobe in ventral view narrow, its outline convex apically ( Figs. 100­101, 104 ­ 105View FIGURES 100 ­ 107), in lateral view strait, without apical denticle or obtuse projection ventrally ( Figs. 102­103, 106 ­ 107View FIGURES 100 ­ 107), distal diverticula of internal sac in ventral view broad ( Figs. 111­112View FIGURES 108 ­ 119).

Spermatheca as in Fig. 113View FIGURES 108 ­ 119.

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

Natural History. Geostiba nimbicola  was collected at altitudes above 1500 m in moss or in leaf litter in mixed forest with red spruce ( Picea rubens  ), Fraser’s fir ( Abies fraseri  ), birch and oak.

CNCI

Canadian National Collection Insects

FMNH

Field Museum of Natural History

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Staphylinidae

Genus

Geostiba

Loc

Geostiba (Sibiota) nimbicola Lohse & Smetana, 1988

Gusarov, Vladimir I. 2002
2002
Loc

Geostiba nimbicola

Lohse 1988: 275
Loc

Geostiba bicarinata:

Pace 1997: 106
Lohse 1988: 273