Achilia elguetai n. sp. Figs 5, 15, 26-27, 34, 37, 49, 67-70, 83 Holotype: MHNG (# MHNG-ENTO-81674); 1 ♂; SOUTHERN CHILE: Región Los Lagos: Chiloé prov.: Isla Chiloé, Vilupulli; 26.II.1976; T. Cekalovic. Paratypes (29 ex.): SOUTHERN CHILE Región Los Lagos: Chiloé prov.: MHNG (# MHNG- ENTO-81675-80); 6 ♀; same data as holotype. – MSNG; 1 ♂; Puente La Caldera, 15.II.1996; site TC-466; T. Cekalovic. – FMNH (FMHD# 97-21); 5 ♂ and 5 ♀; Puente La Caldera, 9.8 km E of Cucao; 42° 39.96’S 74° 00.70’W; 10 m; 14.I.1997; site 991, valdivian raiforest, berlese, leaf & log litter; A. Newton & M. Thayer. – MHNG (# MHNG-ENTO-81681-82); 1 ♂ and 1 ♀; same data. – MNHS; 1 ♂ and 1 ♀; same data; A. Newton & M. Thayer 991. – MHNG (# MHNG-ENTO-81683-84); 2 ♀; Isla Chiloé, Castro; 26.II.1976; T. Cekalovic. – MHNG (# MHNG- ENTO-81685); 1 ♂; Chiloé National Park, Rancho Grande, near Cucao; 42° 33’S 74° 02’W; 250-400 m; 29.XII.1992; site 35b, sifting of moss on forest floor trees and vegetational debris; D. Burckhardt. – FMNH (FMHD #2002-72); 5 ♂; S side of Huillinco lake, road to Bellavista; 1.3 km S road of Cucao; 42° 41.81’S 73° 55.88’W; 45 m; 12-22.XII.2002; site 1062, valdivian rainforest w/emergent Saxegothea conspicua, flight intercept trap; A. Newton & M. Thayer. Description: Body 1.60-1.70 mm long, brown with reddish, or sometimes yellowish elytra; antennae and legs reddish or yellowish; palpi yellowish. Pronotum with disc very convex; posterior portion of lateral margins suparallel. First abdominal tergite with diverging basal striae extending to about one-third of paratergal length, and separated at base by about onethird of tergal width. Male: Head as in Figs 67-70, with occipital region and basal half of frons raised as two quadrangular protuberances, and separated by U-shaped median notch; lateral arms of notch extended anteriorly as pubescent pointed process that is densely pubescent apically; anterior portion of frons deeply excavated; median apophysis curved and directed backwards, originating from large median sub-basal clypeal hump, tip in dorsal view lozenge-shaped with pubescent sides; median subbasal clypeal hump with sides sharp and bearing sparse bristles. Antennae (Fig. 15) with scape barely longer than wide; pedicel distinctly longer than wide; antennomeres III-V distinctly longer than wide; antennomere VI slightly longer than wide; antennomeres VII and VIII wider than long; antennomeres IX-X transverse with slightly protruding lateral margin, antennomere X wider than IX; antennomere XI elongate with denticulate margins, and shorter than VII-X combined. Metaventrite with distal half densely pubescent, raised at middle for twothirds of its distal portion, this surface entirely divided by median sulcus. Protrochanters with one long seta and some shorter setae, ventral margin forming median spine (Fig. 26), this spine sometimes truncate (Fig. 27); protibiae (Fig. 37) strongly recurved and sinuate for distal half; mesotrochanters with ventral margin forming sharp spine at basal third (Fig. 34); mesofemora (Fig. 34) with basal third of ventral margin covered by broad, short and thick setae, similar to those of A. jeanneli n. sp.; mesotibiae with medial margin without recurved setae (Fig. 49), forming very short and rounded apical spine; apical margin forming very small second spine. Aedeagus (Fig. 5) 0.31-0.32 mm long; very similar to that of A. delamarei except parameres slightly wider, and copulatory pieces with medial sclerites with only the distal third frayed with numerous long and thin spines. Female: Similar to male except head not modified with frons flattened, and frontal sulcus scarcely impressed. Collecting data: Collected from December to February in valdivian rainforest at elevations ranging from 10 m to 400 m. The specimens came from sifted samples of leaf & log litter, or from moss and vegetational debris, some also collected by flight intercept traps. Distribution: Achilia elguetai n. sp. is known only from southern Chile (Fig. 83: red inverted triangles) in Chiloé province (Región Los Lagos). Etymology: This species is dedicated to the Chilean entomologist M. Elgueta Donoso. Comments: Achilia elguetai n. sp. is easily distinguished from the other species of the A. grandiceps group by the peculiar characters of the males, especially the features of the head (Figs 67-70), the antennae (Fig. 15), and the protibiae (Fig. 37). The females of this species are characterized by their very large head, which is flattened but not excavated behind the scarcely impressed frontal sulcus, the frontal lobe is distinctly pointed at the middle, the antennae have antennomeres III and V distinctly longer than wide, antennomeres VI and VII are slightly longer than wide, and the protibiae are enlarged for their distal half.

Published as part of Sabella, Giorgio, Cuccodoro, Giulio & Kurbatov, Sergey A., 2020, A revision of the Chilean Brachyglutini - Part 6. Revision of Achilia Reitter, 1890: A. grandiceps, A. valdiviensis, and A. bicornis species groups (Coleoptera: Staphylinidae: Pselaphinae), pp. 129-156 in Revue suisse de Zoologie 127 (1) on pages 136-137, DOI: 10.35929/RSZ.0013, http://zenodo.org/record/5743391