Sableta (Anatheta) planulicollis Casey, 1910:112

Ashe, James S. & Gusarov, Vladimir I., 2003, Review of Anatheta Casey (Staphylinidae: Aleocharinae: Athetini), with Notes on Synonymy of Canastota Casey and Silusida Casey, The Coleopterists Bulletin 57 (1), pp. 27-36 : 32-33

Sableta (Anatheta) planulicollis Casey, 1910:112

Metaxya erudita Casey 1911:135 , syn. nov.

Description. Length 2.9–3.5 mm. Head dark brown, contrasting markedly with lighter pronotum and elytra in most specimens; pronotum and elytra light brown in most, medium brown in a few; abdomen light brown to medium brown, with various of terga III–VI darker, most with terga V–VII medium brown medially and light brown on distal margins, the posterior half of tergum VII and tergum VIII light brown.

Surface of disk of head mat, microsculpture dense, obscuring fine and shallow puncturation, distance between punctures about equal to their diameter. Antennal article 2 longer than article 3, article 4 subquadrate, articles 5–10 increasingly transverse (penultimate article 1.5 times wider than long), last article about as long as articles 9 and 10 combined.

Pronotum transverse, width to length ratio 0.59 mm: 0.47 mm (average for 11 males), wider than head (pronotum width to head width ratio 0.59 mm: 0.49 mm); surface mat, with finer and denser puncturation than on head, distance between punctures about ½ their diameter. Elytra measured from humeral angle shorter than wide (0.60 mm: 0.72 mm), mat, microsculpture and puncturation as on pronotum.

Abdominal terga with weak transverse microsculpture, and fine puncturation, distance between punctures equals 1–2 times their diameter on terga III–VI, 2–3 times their diameter on tergum VII. In both sexes sternum VIII protruding (more so in males), rounded apically, longer than tergum VIII, tergum VIII slightly convex apically.

Aedeagus: As in Figures 15, 16 .

Spermatheca: As in Figure 17 .

Diagnosis. Anatheta planulicollis is very close to A. surrufa and can only be reliably distinguished by aedeagus shape and the larger spermatheca of A. planulicollis . On average A. planulicollis is larger (body length 2.9–3.5 mm in comparison to 2.5–3.0 mm for A. surrufa ) and slightly darker. Because in dry specimens of staphylinids the abdomen is expanded or contracted to a variable extent, the measurements of single body parts are usually more useful for distinguishing close species. Indeed, pronotum width and length range from 0.56 to 0.65 and from 0.45 to 0.49 mm, respectively, in A. planulicollis (11 males measured), whereas in A. surrufa (5 males) the comparable ranges are 0.52–0.56 and 0.42–0.45 mm. Specimens that fall in overlapping zone of these distributions can be reliably distinguished only by comparing their genitalia.

Distribution. Known from U.S.A. (Kansas) and Canada (Manitoba).

Natural History. Casey (1910, 1911) did not provide habitat information. However, new data show that the species is fairly abundant in mammal (gopher and kangaroo rat) burrows in Kansas where it is frequently found in association with specimens of A. surrufa . One specimen was collected in deer dung.

Holotype of Sableta (Anatheta) planulicollis Casey 1910 , $, with labels as follows: ‘‘Meade Ks 5/14/01’’, ‘‘ Anatheta planulicollis Csy. ’’, ‘‘Casey bequest 1925’’, ‘‘TYPE USNM 39142’’ (red label). Casey (1910) specifically stated that he had only a single specimen available to him (in referring to his 2 new species of Anatheta , he mentioned ‘‘...two unique types...’’, p. 112). Therefore, the specimen labeled ‘‘ Anatheta planulicollis ’’ in the Casey collection is, by definition, the holotype. We have added the following label: ‘‘ HOLOTYPE, Sableta planulicollis Casey 1910 ’’.

Lectotype of Metaxya erudita Casey 1911 (here designated), #, with labels as follows: ‘‘Aweme Manitoba N. Criddle’’, ‘‘ erudita Csy. ’’, ‘‘Casey bequest 1925’’, ‘‘TYPE USNM 39070’’ (red label), ‘‘ LECTOTYPE, Metaxya erudita Casey 1911 , Designated: J.S. Ashe and V. I. Gusarov, 2001’’. There is a second specimen in the M. erudita unit tray in Casey collection. It is a female labeled as follows: ‘‘Aweme Manitoba N. Criddle’’, ‘‘Placed exactly midway between erudita 1 surrufa , perhaps as an intergrading link between these 2 species’’, ‘‘Casey bequest 1925’’, ‘‘Casey determ.? erudita -2’’. While describing M. erudita, Casey (1911) did not specifically state how many specimens were available. Since Casey was clearly not certain about the identity of the second specimen, it cannot be considered a syntype. The first specimen is here designated as the lectotype to assure correct and consistent application of the name in the future.

Additional material (28 specimens, KSEM), with labels as follows: U.S.A.: Kansas: Kiowa Co., 8 km N Greenburg, 19 March 1997, G. Salsbury, kangaroo rat burrow, KAN2 S99 034 (#, $); same locality and collector, 19 April 1996, emu dung trap in kangaroo rat burrow, KAN2S99 074 (6#, 7$) ; same locality and collector, 23 March 1997, kangaroo rat burrow, KAN2 S99 59 (2#, 4$) ; same locality and collector, 15 March 1997, gopher burrow, KAN2S99 099 (2#, 3$) ; same locality and collector, 25 February 1998, gopher burrow dung trap, KAN2 S99 049 ($) ; Bourbon Co., 14.5 km SW Ft. Scott , 20 March 1997, G. Salsbury, deer dung, KAN2S99 079 ($) .

Figures

Figs. 9–17. Anatheta planulicollis (Casey). 9) Meso-metasternum; 10) left anterior tibia and tarsus; 11) left middle tibia and tarsus; 12) left hind tibia and tarsus; 13) male tergum VIII; 14) male sternum VIII; 15) aedaegus, lateral aspect; 16) aedeagus, dorsal aspect; 17) spermatheca.