Geostiba

Gusarov, Vladimir I., 2002, A revision of Nearctic species of the genus Geostiba Thomson, 1858 (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 81, pp. 1-88: 15-17

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-FF90-3932-4D2D-FE42FAC3FE5F

treatment provided by

Plazi

scientific name

Geostiba
status

 

Key for Identification of Nearctic Species of Geostiba 

1 In males pronotum with one medial tubercle at posterior margin; each elytron with a tubercle near scutellum but not at the elytral suture; abdominal tergum 7 with one short medial carina in front of posterior margin. Posterior margin of female sternum 8 distinctly convex, without medial emargination. Aedeagus: Figs. 1­3View FIGURES 1 ­ 7 in Assing (2001). Spermatheca: Fig. 4View FIGURES 1 ­ 7 in Assing (2001). Body length 2.3­2.8 mm, pronotal width 0.43­0.53 mm. Introduced from Europe to Newfoundland ( Fig. 336View FIGURE 336) ................ ......................................................................... 15. G. (s. str.) circellaris (Gravenhorst)  .

– In males pronotum without a medial tubercle at posterior margin; elytral suture is raised behind scutellum (flat in G. impressula  ); abdominal tergum 7 with two short and parallel medial carinae in front of posterior margin or without carinae. Posterior margin of female sternum 8 medially slightly concave or with emargination ( Figs. 32 ­ 33View FIGURES 29 ­ 33, 54­ 55View FIGURES 51 ­ 56). Native Nearctic species ........................................................................... 2

2 Species occurring in eastern North America, east of the Rocky Mountains................. 3

– Species occurring in western North America, west of the Rocky Mountains ............ 15

3 Temples 2.3­2.7 times as long as eyes. Elytra (measured from humeral level) longer than pronotum. Wings fully developed. In males abdominal tergum 7 with two short and parallel medial carinae in front of posterior margin, abdominal tergum 8 with four short and weak carinae in front of posterior margin. Apex of median lobe in lateral view bent ventrally and widened apically ( Figs. 36­37View FIGURES 34 ­ 37). Body length 1.9­2.4 mm, pronotal width 0.40­0.47 mm. Widely distributed in eastern North America from Mount Rogers, Virginia in the south to Maine, Québec and Wisconsin in the north ( Fig. 337View FIGURE 337)................................................ 1. G. (Sibiota) appalachigena Gusarov  , sp. n.

– Temples 2.7 ­6.0 times as long as eyes. Elytra shorter than pronotum. Wings reduced to short vestiges, shorter than elytra. Apex of median lobe of aedeagus has different shape. Distributed in the Southern Appalachians (North Carolina and Tennessee) ( Figs. 337­338View FIGURE 337View FIGURE 338) ............................................................................................................ 4

4 Males (In males posterior margin of abdominal sternum 8 convex and without a fringe of wide setae ( Fig. 30View FIGURES 29 ­ 33) and some species with two medial carinae on tergum 7) ....... 5

– Females (In females posterior margin of abdominal sternum 8 medially emarginate or concave, with a fringe of wide setae ( Figs. 32 ­33View FIGURES 29 ­ 33, 54­ 55View FIGURES 51 ­ 56). Females never have carinae on abdominal terga 7­8). Females can be reliably identified only by association with males or by comparing locality data with known geographical distribution of different species of Geostiba  .

5 Abdominal tergum 7 with two short and parallel medial carinae in front of posterior margin, tergum 8 with four short and weak carinae in front of posterior margin ....... 6

– Abdominal terga 7 and 8 without carina or tubercles ................................................ 12

6 Body length 1.9­2.3 mm, pronotal width 0.40­0.46 mm. Antennal segment 4 slightly transverse (width to length ratio about 1.2; Fig. 16View FIGURES 8 ­ 17). Apex of median lobe in ventral view broad ( Figs. 57 ­58View FIGURES 57 ­ 60, 77­ 78View FIGURES 77 ­ 80) .................................................................................. 7

– Body length 1.6­2.3 mm, pronotal width 0.34­0.43 mm. Antennal segment 4 strongly transverse (width to length ratio about 1.6; Fig. 17View FIGURES 8 ­ 17). Apex of median lobe in ventral view narrow ( Figs. 100­101View FIGURES 100 ­ 107, 126­ 127View FIGURES 126 ­ 133, 152­ 153View FIGURES 152 ­ 156) or broad (in G. balsamensis  only, Figs. 193­194View FIGURES 193 ­ 196) ............................................................................................................. 8

7 Apex of median lobe of aedeagus in lateral view not bent ventrally ( Figs. 59­60View FIGURES 57 ­ 60). Body length 2.0­ 2.3 mm, pronotal width 0.40­0.46 mm. Known from the Great Balsam Mountains and Little Pisgah Mountain in the Southern Appalachians( Figs. 338View FIGURE 338, 340View FIGURE 340) ................................................................... 2. G. (Sibiota) bicarinata Lohse & Smetana 

– Median lobe of aedeagus in lateral view bent ventrally ( Figs. 79­80View FIGURES 77 ­ 80). Body length 1.9­ 2.3 mm, pronotal width 0.41­0.44 mm. Known from Graveyard Ridge and Black Balsam Knob in the Great Balsam Mountains – Pisgah Ridge massif in the Southern Appalachians ( Figs. 338View FIGURE 338, 340View FIGURE 340) .............................. 3. G. (Sibiota) graveyardensis Pace 

8 Apex of median lobe in ventral view broad ( Figs. 193­194View FIGURES 193 ­ 196). Medial carinae on male tergum 7 weak. Body length 1.8­2.2 mm, pronotal width 0.36­0.39 mm. Known from the Plott Balsams – Cataloochee Divide massif in the Southern Appalachians ( Figs. 338View FIGURE 338, 340View FIGURE 340) ................................................................... 8. G. (Sibiota) balsamensis Pace 

– Apex of median lobe in ventral view narrow ( Figs. 100­101View FIGURES 100 ­ 107, 126­ 127View FIGURES 126 ­ 133, 152­ 153View FIGURES 152 ­ 156). Medial carinae on male tergum 7 strong ..................................................................... 9

9 Apex of median lobe in lateral view with obtuse ventral projection ( Figs. 176­177View FIGURES 174 ­ 177). Body length 1.8­2.3 mm, pronotal width 0.34­0.40 mm. Known from Snake Den Mountain in the Great Smoky Mountains massif ( Figs. 338View FIGURE 338, 340View FIGURE 340) ................................................................................................ 7. G. (Sibiota) crepusculigena Gusarov  , sp. n.

– Apex of median lobe in lateral view without obtuse ventral projection ( Figs. 102­103View FIGURES 100 ­ 107, 128­ 129View FIGURES 126 ­ 133, 155­ 156View FIGURES 152 ­ 156) ..................................................................................................... 10

10 Apex of median lobe longer ( Figs. 100­107View FIGURES 100 ­ 107), in ventral view the apex outline convex apically ( Figs. 101, 105View FIGURES 100 ­ 107), in lateral view without denticle ( Figs. 103, 107View FIGURES 100 ­ 107). Body length 1.6 ­2.0 mm, pronotal width 0.37­0.40 mm. Known from many localities in the Great Smoky Mountains massif ( Figs. 338View FIGURE 338, 340View FIGURE 340) .............................................................................................................................. 4. G. (Sibiota) nimbicola Lohse & Smetana 

– Apex of median lobe shorter ( Figs. 126­133View FIGURES 126 ­ 133, 152­ 156View FIGURES 152 ­ 156), in ventral view the apex outline often doubly emarginate ( Figs. 131View FIGURES 126 ­ 133, 153­ 154View FIGURES 152 ­ 156), in lateral view with a denticle ( Figs. 128­129View FIGURES 126 ­ 133, 155­ 156View FIGURES 152 ­ 156) ........................................................................................... 11

11 Apex of median lobe in lateral view with a strong ventral denticle ( Figs. 155­156View FIGURES 152 ­ 156), in ventral view the apex outline strongly doubly emarginate ( Figs. 152­154View FIGURES 152 ­ 156). Body

length 1.6­1.9 mm, pronotal width 0.37­0.40 mm. Known from many localities in the Great Smoky Mountains massif ( Figs. 338View FIGURE 338, 340View FIGURE 340) .......................................................... ...................................................................... 6. G. (Sibiota) nebuligena Gusarov  , sp. n. – Apex of median lobe in lateral view with a weak ventral denticle ( Figs. 128­129View FIGURES 126 ­ 133), in ventral view the apex outline weakly doubly emarginate ( Figs. 130­131View FIGURES 126 ­ 133) or convex ( Figs. 126­127, 132 ­ 133View FIGURES 126 ­ 133). Body length 1.9­2.2 mm, pronotal width 0.36­0.43 mm. Known from the Plott Balsams – Cataloochee Divide massif in the Southern Appalachians ( Figs. 338View FIGURE 338, 340View FIGURE 340) .................................. 5. G. (Sibiota) pluvigena Gusarov  , sp. n.

12 Body length 1.8­2.2 mm, pronotal width 0.34­0.39 mm. Lateral sides of the apex of median lobe with shallow emargination (in ventral view) ( Figs. 219­220, 223 ­ 229View FIGURES 219 ­ 229, 249­ 250View FIGURES 247 ­ 252) ..................................................................................................................... 13

– Body length 1.9­2.6 mm, pronotal width 0.39­0.44 mm. Lateral sides of the apex of median lobe with deep emargination (in ventral view) ( Figs. 267­268View FIGURES 267 ­ 270, 289­ 291View FIGURES 289 ­ 293) ..... 14

13 Median lobe of aedeagus in ventral view more narrow ( Figs. 219­220, 223 ­ 229View FIGURES 219 ­ 229). Distal diverticula of internal sac long ( Figs. 233­234View FIGURES 230 ­ 246), proximal diverticula small ( Fig. 234View FIGURES 230 ­ 246). Body length 1.8­2.2 mm, pronotal width 0.34­0.39 mm. Known from the Great Balsam Mountains – Pisgah Ridge massif and from Standing Indian in the Blue Ridge in the Southern Appalachians ( Figs. 338View FIGURE 338, 340View FIGURE 340) .............................................................. .................................................................... 9. G. (Sibiota) nubigena Lohse & Smetana 

– Median lobe of aedeagus in ventral view wider ( Figs. 249­250View FIGURES 247 ­ 252). Distal diverticula of internal sac short and small ( Figs. 253, 256View FIGURES 253 ­ 261), proximal diverticula very large ( Figs. 253, 257 ­ 258View FIGURES 253 ­ 261). Body length 1.8­1.9 mm, pronotal width 0.34 mm. Known only from the Great Smoky Mountains west of Clingmans Dome ( Figs. 338View FIGURE 338, 340View FIGURE 340) ...................... ..................................................................... 10. G. (Sibiota) coeligena Gusarov  , sp. n.

14 Median lobe of aedeagus longer ( Fig. 269View FIGURES 267 ­ 270), in lateral view more narrow ( Figs. 269­ 270View FIGURES 267 ­ 270), in ventral view the lateral sides of the apex less convex ( Figs. 267­268View FIGURES 267 ­ 270). Body length 1.9­2.4 mm, pronotal width 0.39­0.44 mm. Known only from the Great Craggy Mountains and the Black Mountains in the Southern Appalachians ( Figs. 338­339View FIGURE 338View FIGURE 339) .... ..................................................................... 11. G. (Sibiota) alticola Lohse & Smetana 

– Median lobe of aedeagus shorter ( Fig. 292View FIGURES 289 ­ 293), in lateral view broader ( Figs. 292­293View FIGURES 289 ­ 293), in ventral view the lateral sides of the apex more convex ( Figs. 289­291View FIGURES 289 ­ 293). Body length 2.2­2.6 mm, pronotal width 0.40­0.44 mm. Known only from Roan Mountain and the Big Bald (Bald Mountains) in the Southern Appalachians ( Figs. 338­339View FIGURE 338View FIGURE 339) .................. ................................................................................... 12. G. (Sibiota) carteriensis Pace 

15 Elytra (measured from humeral level) shorter than pronotum. Wings reduced, shorter than elytra. In males pronotum with strong, wide and deep impression along midline. Median lobe of aedeagus with wider apex (in ventral view) ( Figs. 310­312, 315View FIGURES 310 ­ 315). Body length 2.2­2.7 mm, pronotal width 0.37­0.50 mm. Known from Oregon ( Fig. 336View FIGURE 336) ................................................................................ 13. G. (Sibiota) impressula (Casey) 

– Elytra as long as pronotum. Wings fully developed. In males pronotum without deep impression along midline. Median lobe of aedeagus with more narrow apex (in ventral view ( Figs. 323­324View FIGURES 321 ­ 326). Body length 2.4 mm, pronotal width 0.41 mm. Known from California ( Fig. 336View FIGURE 336)............................ 14. G. (Sibiota) silvigena Gusarov  , sp. n.