Geostiba (Sibiota) pluvigena Gusarov

Gusarov, Vladimir I., 2002, A revision of Nearctic species of the genus Geostiba Thomson, 1858 (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 81, pp. 1-88: 36-39

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-FFBD-3905-4D2D-FEA7FDDBFDFC

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Plazi

scientific name

Geostiba (Sibiota) pluvigena Gusarov
status

 

5. Geostiba (Sibiota) pluvigena Gusarov  , sp. n. ( Figs. 120­145View FIGURES 120 ­ 125View FIGURES 126 ­ 133View FIGURES 134 ­ 145)

Geostiba bicarinata: Lohse & Smetana, 1988: 273  , ex parte (misidentification).

Type material. Holotype ,, UNITED STATES: North Carolina: Haywood Co. / Jackson Co.: junction of Blue Ridge Parkway and Balsam Mountain Road, 17 km W Waynesville, 35 ° 29.72 'N 83 ° 10.43 'W, 1600 m, in forest litter, Picea rubens  , Fagus grandifolia  , Betula  , Rhododendron  , Maianthemum canadense  , Oxalis (V.I.Gusarov)  , 2.vi. 2001 ( KSEM).

Paratypes: UNITED STATES: North Carolina: Haywood Co. / Jackson Co.: 99 specimens, same data as the holotype ( KSEM, AMNH, CNCI, SPSU, FMNH); 43 specimens, Waterrock Knob, N slope, 13 km W Waynesville, 35 °28.0'N 83 °08.2'W, 1900 m, in forest litter, Picea rubens  , Abies fraseri  , Rubus  , Oxalis (V.I.Gusarov)  , 2.vi. 2001 ( KSEM, SPSU); Haywood Co.:, Blue Ridge Parkway, Browning Knob Mt. [35 ° 27 ' 47 "N 83 °07' 55 "W], 1830­1890 m (A.Smetana), 28.v. 1986 ( Lohse and Smetana (1988) listed this specimen as a paratype in the type series of G. bicarinata  )( CNCI).

Diagnosis. Geostiba pluvigena  can be distinguished from other Nearctic species of Geostiba  by having small eyes (temple length to eye length ratio 2.7­3.8), 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. 126­138, 140 ­ 145View FIGURES 126 ­ 133View FIGURES 134 ­ 145) and the shape of the spermatheca ( Fig. 139View FIGURES 134 ­ 145).

Geostiba pluvigena  is closely related to G. nimbicola  , G. nebuligena  and G. crepusculigena  . Geostiba pluvigena  differs from G. nimbicola  in having shorter and broader (in ventral view) apex of median lobe with weak apical denticle (in lateral view) ( Figs. 126­ 133View FIGURES 126 ­ 133, 100­ 107View FIGURES 100 ­ 107); from G. nebuligena  in having weaker apical denticle of median lobe of aedeagus ( Figs. 128­129View FIGURES 126 ­ 133, 155­ 156View FIGURES 152 ­ 156); from G. crepusculigena  in lacking obtuse projection on the ventral side of the apex of median lobe ( Figs. 128­129View FIGURES 126 ­ 133, 176­ 177View FIGURES 174 ­ 177).

Description. Length 1.9­2.2 mm. Brown, pronotum, elytra and 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 2.7­3.8. Antennal article 2 longer than article 3, article 4 transverse (width to length ratio 1.6), articles 5­10 strongly transverse (ratio 1.7­1.9), last article as long as 9 and 10 combined ( Fig. 17View FIGURES 8 ­ 17).

Pronotum as wide as long, width 0.36­0.43 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 2­5 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. 120View FIGURES 120 ­ 125). Male sternum 8 with convex posterior margin ( Fig. 121View FIGURES 120 ­ 125).

Female tergum 8 with convex posterior margin ( Fig. 122View FIGURES 120 ­ 125), sternum 8 with emarginate posterior margin ( Figs. 123­124View FIGURES 120 ­ 125).

Aedeagus as in Figs. 126­138, 140 ­ 145View FIGURES 126 ­ 133View FIGURES 134 ­ 145. Apex of median lobe in ventral view narrow, its outline convex or doubly emarginate apically ( Figs. 126­127, 130 ­ 133View FIGURES 126 ­ 133), in lateral view strait, with weak apical denticle ventrally ( Figs. 128­129View FIGURES 126 ­ 133), distal diverticula of internal sac in ventral view broad ( Figs. 137­138View FIGURES 134 ­ 145).

Spermatheca as in Fig. 139View FIGURES 134 ­ 145.

Distribution. Known from the Plott Balsams – Cataloochee Divide massif (North Carolina) ( Figs. 338View FIGURE 338, 340View FIGURE 340).

Natural History. Geostiba nimbicola  was collected at altitudes above 1600 m in leaf litter in mixed forest with red spruce ( Picea rubens  ).

Etymology. The specific name is derived from the Latin adjective pluvius (rainy) and the verb gigno (to be born, to arise). It refers to the rains in the Southern Appalachians 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

Loc

Geostiba (Sibiota) pluvigena Gusarov

Gusarov, Vladimir I. 2002
2002
Loc

Geostiba bicarinata:

Lohse 1988: 273