Achilia trauco, Kurbatov & Cuccodoro & Sabella, 2018

Kurbatov, Sergey A., Cuccodoro, Giulio & Sabella, Giorgio, 2018, A revision of the Chilean Brachyglutini – Part 3. Revision of Achilia Reitter, 1890: A. frontalis species group (Coleoptera: Staphylinidae: Pselaphinae), Revue suisse de Zoologie 125 (1), pp. 165-188 : 179-183

Achilia trauco n. sp.

Figs 28 , 36 , 46, 51 , 77, 79, 84

Type material (75 ex.): CENTRAL CHILE: Región Los Ríos: Ranco prov.: MHNG; 1 ♂ (holotype); 34 km WNW La Union, station 36; 700 m; 17.XII.1984; S. & J. Peck; litter mixed evergreen forest. – Región Los Lagos: Osorno prov.: FMNH ( FMHD #96-249 ); 1 ♂ and 1 ♀ (paratypes); 15.1 km W Puaucho; 40° 34.97’S 73° 37.68’W; 50 m; 30.XII.1996; A. Newton & M. Thayer 984; valdivian rainforest remnant in sm. ravine, w/large ferns, berlese, leaf & log litter. – Región Los Ríos: Ranco prov. : MHNG; 16 ♂ and 12 ♀ (paratypes); 34 km WNW La Union, station 36; 700 m; 17.XII.1984; S. & J. Peck; litter mixed evergreen forest. - MNHS; 1 ♂ and 1 ♀ (paratypes); same data; S. & J. Peck; litter mixed evergreen forest. – FMNH ( FMHD #85- 921 , # 85-36 ); 1 ♂ and 4 ♀ (paratypes); same data; S. & J. Peck. – MHNG; 12 ♂ and 1 ♀ (paratypes); 35 km WNW La Union; 700 m; 07.II.1985; S. & J. Peck; litter mixed forest. – FMNH ( FMHD #85-997 , # 85-36 ); 1 ♂ and 1 ♀ (paratypes); same data; S. & J. Peck; litter mixed forest. – Región Araucanía: Malleco prov. : FMNH ( FMHD #85-1001 , # 85-118 ); 1 ♂ and 9 ♀ (paratypes); Purén, Contulmo Natural Monument; 350 m; 13.II.1985; S. & J. Peck; mixed forest litter, berlese. – MHNG; 1 ♂ and 7 ♀ (paratypes); same data; S. & J. Peck. – Región Bío Bío: Arauco prov.: FMNH; 1 ♂ and 5 ♀ (paratypes); 16 km N Tres Pinos; 170 m; 12.XII.1982; A. Newton & M. Thayer; Cupressus , Eucalyptus etc. forest, berlese, leaf & log litter, forest floor .

Description: Body 1.15-1.4 mm long, generally bicolored with head, pronotum and abdomen blackish; elytra, antennae, and legs reddish, and palpi yellowish. Head with eyes longer than temples. Pronotum wider than head, with maximal width on anterior half and median antebasal fovea as large as lateral ones. First abdominal tergite with basal striae slightly diverging, extending to about one-third of paratergal length, and separated at base by about one-third of tergal width.

Head as in Figs 77 and 79 ; flanked by two deep lateral pits anteriorly at eyes, the upper margin of eyes surmounted by large carina; frontal protuberance very swollen. Antennae as in A. frontalis . Metasternum with deep ovoidal median depression; posterior edge of the depression pubescent. Legs with trochanters simple; all femora ( Fig. 36 ) thickened and sinuate, particularly metafemora; protibiae ( Fig. 46 ) slightly thickened on distal half; mesotibiae ( Fig. 51 ) at middle slightly bulging and bearing tuft of short setae; medial edge of metatibiae densely pubescent on apical half and distinctly narrowed subapically. Abdominal tergites unmodified; first abdominal ventrite impressed at middle, remaining ventrites flattened at middle; ventrite I with median carina extending from posterior margin to posterior edge of median impression. Aedeagus ( Fig. 28 ) 0.23-0.27 mm long; similar to that of A. frontalis , differing only by copulatory pieces being sinuate and subapically narrowed. Parameres wide with long seta on poorly developed outer lobe; tips recurved posteriorly and bearing thin and long subapical seta.

Female: Similar to male except: head with occipital protuberance less developed and lacking lateral pits; eyes less developed; disc of pronotum less convex; metasternum, abdomen, and legs unmodified.

Collecting data: Collected from December to February, mainly in mixed evergreen forests at elevations ranging from 50 m to 700 m. The specimens came from sifted samples of leaf and log litter.

Distribution: Achilia trauco n. sp. is distributed in Central Chile from Osorno to Arauco Provinces ( Fig. 84 : pink squares).

Comments: Achilia trauco n. sp. is very similar to A. frontalis , from which it differs mainly by the male features of head (see Figs 71-76 , 77, 79 ), of the metafemora (see Figs 37-40, 36 ), the protibiae (see Figs 45 and 46 ), the mesotibiae (see Figs 50, 51 ), and the aedeagi (see Figs 27, 28 ). The females of A. frontalis and A. trauco n. sp. are very similar, except that those of A. trauco n. sp. have a slightly longer head, with a frontal protuberance more convex than those of A. frontalis .

Figures

Figs 24-29. Aedeagi of Achilia. (24) A.caracolana, specimen from Hualpèn, prov. Concepción. (25) A. auriculata, specimen from Peniquillo, prov. Concepción. (26) A. ovallensis, specimen from Ovalle, prov. Limarí [paratype]. (27) A. frontalis, specimen from Aguas Calientes to Puyehue National Park, prov. Osorno. (28) A. trauco, specimen from 34 km WNW La Union, prov. Ranco [paratype]. (29) A. longispina, specimen from Mina de la Disputada, prov. Valparaíso.

Figs 35-43. Male profemur (35), metafemur (36), the variability of metafemur (38-40), metaleg (37) and mesotrochanter (41-43) of Achilia. (35, 41) A. caracolana. (36) A. trauco. (37) A. frontalis, specimen from Chillàn. (38) A. frontalis, specimen from Cordillera de Nahuelbuta. (39) A. frontalis, specimen from Frutillar. (40) A. frontalis, specimen from Aguas Calientes to Puyehue National Park. (42) A. ovallensis [paratype]. (43) A. longispina.

Figs 44-52. Male protibia (44-46) and mesotibia (47-52) of Achilia. (44, 47) A. caracolana. (45, 50) A. frontalis. (46, 51) A. trauco. (48) A. ovallensis. (49) A. auriculata. (52) A. longispina.

Figs 77-82. (77, 79) Achilia trauco. (78, 80-82) A. longispina. Male head in (77-78) dorsal, (79-80) lateral and (81) dorso-posterior views. (82) male eye in frontal view. Scale bar left for (77, 79) and right for (78, 80-81).

Fig. 84. Distribution map. (● red circles) Achilia testacea. (▲ blue triangles) A. frontalis. (◆ green diamonds) A. caracolana. (■ pink squares) A. trauco. (✷ yellow stars) A. longispina.

Figs 71-76. Achilia frontalis. (71, 73, 75) specimen from Chillàn. (72, 74, 76) specimen from Frutillar. Male heads in dorsal (71-72) and lateral (73-74) views. (75-76) male supraocular area in lateral view. Scale bar left for (71, 73) and right for (72, 74).