Sableta Casey, 1910

Ashe, James S. & Gusarov, Vladimir I., 2004, Review of the genus Sableta Casey, 1910 (Coleoptera: Staphylinidae: Aleocharinae: Athetini), Zootaxa 745, pp. 1-15 : 3-8

Sableta Casey, 1910

( Figs. 1–26)

Sableta Casey, 1910: 107 (type species, Sableta infulata Casey, 1910 , p. 107–108, fixed by Casey (1910, p.108) by original designation; as a genus in subtribe Athetina Casey, 1910 (spelled as Athetae); including subgenera Canastota Casey, 1910 , Anatheta Casey, 1910 , and Taxicerella Casey, 1910 ).

Sableta: Casey, 1911: 144 (as valid genus in subtribe Athetina (spelled as Athetae); including subgenus Fusalia Casey, 1911 ).

Sableta: Fenyes, 1920: 221 (as a valid subgenus of Atheta ; Canastota , Anatheta , Taxicerella and Fusalia as synonyms of Sableta ).

Sableta: Bernhauer & Scheerpeltz, 1926: 666 (as valid subgenus of Atheta ; Canastota , Anatheta , Taxicerella and Fusalia as synonyms of Sableta ).

Sableta: Moore & Legner, 1975: 353 (as valid subgenus of Atheta ; Canastota , Anatheta , Taxicerella and Fusalia as synonyms of Sableta ).

Sableta: Seevers, 1978: 103 (as valid genus in subtribe Dimetrotina Seevers, 1978 ).

Sableta: Ashe, 2000: 370 (as valid genus in subtribe Dimetrotina Seevers, 1978 ).

Diagnosis. Sableta differs from other genera of Athetini in having a distinctive body color ( Fig. 1); large eyes; transverse antennal segments 8–10; the ligula in the apical half split into two lobes; a transverse pronotum; hypomera fully visible in lateral view; pronotal setation of type V ( Benick & Lohse 1974); mesocoxae moderately separated; the mesothoracic process broad ( Fig. 12 ); the posterior margin of the elytra near posterolateral angle only faintly sinuate; the distinct shape of the male tergum 8 ( Fig. 14 ); a broad (tube­like) athetine bridge of the aedeagus ( Fig. 19 , AB); and the medial lamellae of the internal sac present ( Figs. 21–23 , 25–26 ).

Description. Known species 2.0–2.2 mm in length. Color of known species distinctive; head and pronotum light to medium brown, elytra dark brown with antero­lateral angles flavate to light brown; abdomen flavate with segment VI black to dark brown and tergum VIII black to dark brown except for lighter flavate band on base and baso­lateral areas (see details in description of Sa. infulata below) ( Fig. 1).

Head: Ovoid in dorsal aspect, about 1.3 times as wide as long; temples rounded behind eyes. Eyes large, about 2 times as long as temples behind eyes. Neck absent. Setae on frons directed medially and postero­medially. Infraorbital carina complete or fading just before maxillary insertions in a few specimens. Antenna ( Fig. 7 ) moderately long, reaching basal ¼ of elytra when extended posteriorly; antennal article 3 shorter than article 2, articles 8–10 transverse, last article longer than articles 9 and 10 combined.

Mouthparts: Labrum as in Fig. 2 . Epipharynx as in Fig. 3 ; sensilla a very short or absent; with 3 pairs of marginal setae; anterolateral group with 3 pores, lateral row with 4 pores, posterolateral group with 3–4 pores, medial field with 47–58 pores, transverse row with 6 pores, 1–2 medial proximal pores and no lateral proximal pores. Mandibles as in Figs. 5–6 , “velvety patch” in dorsal molar area with 2–3 transverse rows of small denticles along distal border and scattered minute spinules more basally; right mandible with a small medial tooth. Maxilla as in Figs. 8–10 ; galea only slightly projecting beyond apex of lacinia, apical lobe of galea covered with numerous fine and short setae ( Figs. 8–9 ); lacinia ( Figs. 8, 10 ) with single row of 9 spines in apical third, numerous setae in middle third. Labium as in Figs. 4 , 11 ; ligula about as long as labial palpus article 1, split into 2 lobes in apical half; prementum with medial area narrow, with 6 pseudopores, with two distal setae present, bases close, separated by about width of one setal pore; lateral areas each with 2 real pores, 1 setose pore and 5–7 pseudopores; labial palpi 3­articled, with setae and present, article 2 about 0.5 times length of article 1, article 3 about 1.2 times length of article 1.

Pronotum moderately transverse, 1.3–1.4 times as wide as long in known species; slightly wider in anterior third than basally; convex dorsally in cross section; antero­lateral angles rounded, anterior margin straight; postero­lateral angles obtusely rounded, posterior margin rounded; microsetae directed posteriorly in midline and postero­laterally on sides (Type V; Benick & Lohse 1974); macrosetae black, long and strong, 2 on lateral margins, 1 in posterior angle and two at anterior margin near anterior angles. Hypomera fully visible in lateral view.

Elytra at suture subequal to length of pronotum; postero­lateral margins only faintly sinuate; with one strong and long humeral macroseta and two shorter lateral macrosetae. Wings fully developed.

Legs with tarsal segmentation 4­5­5; anterior tarsi with article 1 shorter than article 2. Middle and hind tarsi with article 1 slightly shorter than 2, articles 2–4 subequal in length, article 5 about as long as 3 and 4 together; with single empodial seta between tarsal claws, about ½ length of tarsal claws. Mesocoxae separated by moderately broad meso­ and metasternal processes ( Fig. 12 ). Mesosternal process broadly rounded apically, extended about 0.4 times length of coxae; isthmus between meso­ and metasternal processes short, only slightly depressed below plane of processes; ratio of mesosternal process:isthmus:metasternal process = 3:1:3.

Abdomen: Sides of abdomen parallel in basal half and converging from segment VI to rounded apex. Each of terga III–VII longer in midline than the respective more anterior tergum. Terga III–V with moderate transverse basal impressions. Tergum VII with white apical fringe. Tergum X with basal semicircular transverse row of densely arranged, flattened setae ( Fig. 15 ).

Secondary sexual features: Males of known species with prominent secondary features on abdominal tergum VIII (see details in description of Sa. infulata below, Fig. 14 ).

Type species. Sableta infulata Casey, 1910 , by original designation. Casey did not specifically state in his description of Sableta that Sa. infulata was the type species of Sableta ; however, while designating the type species of Noverota Casey, 1910 in the same paper, Casey stated (1910, p. 90): “The first species may be regarded as the type, as in all other cases where the type is not specifically named”.

Habitat. Found on lignicolous gilled and polypore mushrooms.

Distribution. The single described species, Sa. infulata , is widely distributed in the eastern United States. We have also seen a number of undescribed species of Sableta from Neotropical regions of Mexico, Central America and South America.

Figures

FIGURES 12 – 16. Sableta infulata Casey. 12 — meso­ and metathorax, ventral aspect; 13 — male abdominal sternum VIII; 14 — male abdominal tergum VIII; 15 — abdominal tergum X; 16 — paramere. Scale bar 0.2 mm (13 – 16), 0.4 mm (12).

FIGURES 17 – 24. Sableta infulata Casey. 17 — aedeagus, median lobe with retracted internal sac, parameral aspect; 18 — apex of median lobe, parameral aspect; 19 — median lobe with retracted internal sac, lateral aspect; 20 — apex of median lobe, lateral aspect; 21 — apex of median lobe with retracted internal sac, parameral aspect; 22 — apex of median lobe with retracted internal sac, abparameral aspect; 23 — apex of median lobe with retracted internal sac, lateral aspect; 24 — spermatheca. AB — athetine bridge; CP — copulatory piece; ML — medial lamellae. Scale bar 0.1 mm (18, 20 – 24), 0.2 mm (17, 19).

FIGURES 25 – 26. Sableta infulata Casey. 25 — apex of median lobe with everted internal sac, parameral aspect; 26 — apex of median lobe with everted internal sac, lateral aspect. CP — copulatory piece; ML — medial lamellae. Scale bar 0.1 mm.

FIGURES 7 – 11. Sableta infulata Casey. 7 — right antenna; 8 — right maxilla, ventral aspect; 9 — right galea, dorsal aspect; 10 — right lacinia, dorsal aspect; 11 — prementum. Scale bar 0.1 mm (8 – 11), 0.2 mm (7).

FIGURES 2 – 6. Sableta infulata Casey. 2 — labrum, dorsal aspect; 3 — epipharynx, adoral aspect; 4 — mentum; 5 — right mandible, ventral aspect; 6 — right mandible, dorsal aspect. Scale bar 0.1 mm.