Achilia bifossifrons ( Reitter, 1883 )

Giorgio Sabella, Sergey A. Kurbatov & Giulio Cuccodoro, 2017, A revision of the Chilean Brachyglutini - Part 2. Revision of Achilia Reitter, 1890: A. crassicornis, A. tumidifrons, A. bifossifrons, and A. lobifera species groups (Coleoptera: Staphylinidae: Pselaphinae), Revue suisse de Zoologie 124 (1), pp. 119-140 : 127-132

Achilia bifossifrons ( Reitter, 1883)

Figs 17 , 23, 26, 33

Bryaxis bifossifrons Reitter, 1883: 50 , pl. 1 fig. 9; Reitter 1885: 325, 329.

Achilia bifossifrons, Jeannel, 1962: 404 , figs 151 (head and an- tenna), 152 (aedeagus).

Type material (1 ex.): CENTRAL CHILI: Región Los Ríos: Valdivia prov.: MNHN (coll. Raffray); 1 ♂ (holotype of Achilia bifossifrons here fixed); Chili.

Additional material (1907 ex.): See Appendix 1.

Description: Body 1.25-1.40 mm long, reddish with dark head, pronotum and abdomen, palpi yellowish. Pubescence on head short and suberect, long and decumbent over rest of body. Head wider than long; frontal lobe flattened with rounded sides; surface smooth, shiny, with some minute punctures; vertexal foveae small; eyes protruding, longer than convex temples. Pronotum wider than long and as wide as head, width maximal at middle; posterior portion of lateral outlines sinuate; disc strongly convex, smooth and shiny; median antebasal fovea slightly smaller than lateral foveae; basal margin bordered with row of contiguous shallow impressions. Elytra together wider than long with protruding humeri; disc smooth, shiny, with some small punctures; generally four basal elytral foveae (two lateral foveae very close and sometimes merged); sutural stria entire; discal stria extending to about elytral midlength. Legs slender. Abdomen smooth, with some minute punctures; tergite I with basal striae slightly diverging, extending to about onethird of paratergal length, separated at base by about one-third of tergal width, with short and sparse setal brush between striae.

Male: Head as in Figs 23 & 26, with occiput very swollen, its anterior margin falls steeply to deep transverse sulcus. Antennae with scape short, as long as wide; pedicel slightlylongerthanwide; antennomeresIII–VIIIsmalland subglobose; antennomere IX transverse with protruding mesal margin; antennomere X transverse and larger than IX, with protruding mesal margin; antennomere XI ovoid, longer than wide and as long as VII-X combined. Metasternum with a large median impression occupying 2/3 of its surface; mesotibiae enlarged at middle and shallowly emarginate subapically. Abdominal tergites unmodified; all abdominal ventrites slightly flattened at middle. Aedeagus ( Fig. 17 ) 0.28-0.29 mm long; dorsal plate elongate with sides sinuate and dorsal strips long and divergent; copulatory pieces consisting of pair of long sclerites curved apically. Parameres with middle seta on distinct lobe, that seta thin, reduced compared to that of the other species treated here; tips broad, recurved posteriorly.

Female: Similar to male except: head with occiput barely swollen; metasternum convex; abdominal ventrites not flattened at middle; mesotibiae unmodified.

Collecting data: Collected from September to April, mainly in Nothofagus-Araucaria forest and secondary and disturbed Valdivian rainforest at elevations ranging from sea level up to about 800 m. Most specimens came from sifted samples of leaf and log litter, moss on forest floor and trees, dead trunks, vegetational debris, and bracket fungi, but also by flight intercept (window) traps, screen sweeping, and car traps.

Distribution: Achilia bifossifrons is distributed in Central Chile from Aysén northward to Ñuble provinces ( Fig. 33 ).

Comments: Reitter (1883) described A. bifossifrons based on what he thought was a unique female from Valdivia. However the description is definitely that of a male, so we recognized the only male we found in Raffray’s collection as the holotype of this species, and labelled it accordingly.

Figures

Fig. 33. Distribution map of Achilia bifossifrons based on examined material.

Figs 14 - 20. Aedeagi (14 - 19) and the left paramere in lateral view (20) of Achilia. (14) A. tumidifrons, paratype from Chepu, Chiloé province. (15) A. larvata, lectotype from environs of Valdivia, Valdivia province. (16) A. globiceps, paratype from Frutillar, Llanquihue province. (17) A. bifossifrons, specimen from Salto Petrohué, Llanquihue province. (18) A. lobifera, specimen from Aguas Calientes, Osorno province. (19 - 20) A. antennalis, specimen from Princesa, Osorno province.