Achilia denticornis Jeannel 1962
Creators: name: Sabella, Giorgio
name: Cuccodoro, Giulio
name: Kurbatov, Sergey A.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Achilia
Achilia denticornis

description: Achilia denticornis Jeannel, 1962
Figs 7-8, 16, 21, 38, 44, 71-74, 83
Achilia denticornis Jeannel, 1962: 421, 423 figs 183 (head and antennae), 184 (aedeagus).
Type material (27 ex.): SOUTHERN CHILI: Región Los Lagos: Chiloé prov.: MHNS; 1 ♂ (holotype); labels verbatim “Type / Chepu, 03.X.1958, G. Kuschel / Achillia denticornis / denticornis (handwritten by Jeannel) / CHILE, M.N.H.N., Typo, n. 1845”. – MNHN; 13 ♂ and 11 ♀ (paratypes); labels verbatim “Paratype / Chepu, 03.X.1958, Kuschel ”. – MNHN; 1 ♂ (paratype); labels verbatim “Paratype / Chepu, 04.X.1958, Kuschel ”. – MNHN; 1 ♂ (paratype); labels verbatim “Paratype / Chepu, 11.X.1958, Kuschel”.
Additional material examined (48 ex.): SOUTHERN CHILI: Región Los Lagos: Chiloé prov.: MHNS; 4 ♂ and 14 ♀ (mislabelled as paratypes of A. denticornis n. 1846-47, n. 1849 and n. 2053-67); Chepu; 03.X.1958; G. Kuschel. – MHNS; 1 ♂ and 4 ♀ (mislabelled as paratypes of A. denticornis n. 1848 and 2068-71); Chepu; 04.X.1958; G. Kuschel. – MHNG; 2 ♂ and 5 ♀; Isla Chiloé, Mocopulli; 2.II.1983; T. Cekalovic. – MHNG; 1 ♀; Isla Chiloé, Piruquina; 19.II.1983; T. Cekalovic. – Llanquihue prov.: FMNH (FMHD #97-38); 2 ♂ and 1 ♀; Vicente Perez Rosales National Park, SW slope Volcan Osorno, km 4 to La Burbuja; 41° 09.95’S 72° 30.80’W; 310 m; 27.I.1997; site 1007 secondary valdivian rainforest w/ Nothofagus dombeyi - Eucryphia cordifolia, berlese, leaf & log; A. Newton & M. Thayer. – FMNH (FMHD #97-16); 1 ♂ and 2 ♀; Lago Chapo, near SE end, km 9.9 on road from Rollizo; 41° 30.63’S 72° 23.98’W; 385 m; 04.I.1997; site 989, valdivian rainforest on steep slope, berlese, leaf & log litter; A. Newton & M. Thayer. – Osorno prov.: PCTS; 1 ♂; Aguas Calientes, 40° 74’S 72° 27’W; 13.XII.2013; car net. – MHNG; 1 ♂ and 7 ♀; Aguas Calientes, 40° 74’S 72° 27’W; 14.XII.2013; litter layer. – FMNH; 1 ♀; Puyehue National Park, Antillanca road; 470 m; 20-25.XII.1982; valdivian rainforest, leaf & log litter, berlese, vouchers associated with larvae; A. Newton & M. Thayer. – FMNH (FMHD #2002-90); 1 ♀; Puyehue National Park, Ruta 215; km 4.5 of Aduana station; 40° 40.23’S 72° 05.21’W; 580 m; 19.XII.2002; site 1071, valdivian rainforest, berlese, leaf & log litter; A. Newton, M. Thayer, D. J. Clarke & M. Chani.
Description: Body 1.60-1.70 mm long, dark brown with reddish elytra; antennae and legs reddish; palpi yellowish. Pronotum with disc moderately convex; posterior portion of lateral margins subparallel. First abdominal tergite with diverging basal striae extending to about one-fourth of paratergal length, and separated at base by about one-third of tergal width.
Male: Head as in Figs 71-74, with occipital region and basal half of frons raised as two protuberances, and separated by U-shaped median notch; lateral arms of notch extended anteriorly to form pubescent pointed process; anterior portion of frons very deeply excavated; median apophysis curved and directed backwards, sides rounded, originating at base of clypeus from ridge connecting base of antennal tubercles, tip in dorsal view triangular with rounded and pubescent sides; anterior margin of transverse clypeal ridge pointed at middle. Antennae (Fig. 16) with scape and pedicel longer than wide, scape slightly swollen; antennomere III sligthly longer than wide; antennomere IV slightly wider than long; antennomere V with distal third of medial margin strongly widened and forming tooth-like process bearing six long apical bristles; antennomeres VI-VIII distinctly wider than long; antennomere IX transverse with distal third of mesal margin protruding to form small tooth; antennomere X wider than long with protruding mesal margin; antennomere XI elongate, distinctly longer than VII-X combined, with margins denticulate. Metaventrite with distal half not pubescent, shiny, raised at middle on apical two-thirds of length, this surface entirely divided by broad and deep median sulcus. Protibiae (Fig. 38) slightly enlarged at middlle, medial margin forming tiny apical spine; mesotrochanters (Fig. 31) with small tubercle near distal third of ventral margin; mesofemora (Fig. 31) with basal third of ventral margin covered by broad, short and thick setae, similar to those of A. grandiceps; mesotibiae (Fig. 44) with medial margin forming conspicuous stout spine at middle and with thin apical spine, without recurved setae. Aedeagus (Figs 7-8) 0.30-0.31 mm long; with suboval dorsal plate, dorsal longitudinal struts slightly divergent. Parameres wide without outer lobe, with enlarged and rounded apex, apex bearing three long and thin bristles. Copulatory pieces consisting of pair of stout lateral sclerites subequal in length, slightly pointed laterally and apically rounded, with pair of long, wide medial sclerites that are basally recurved and sclerotized, these sclerites frayed with numerous long and thin spines.
Female: Similar to male except antennae and head not modified, with frons shallowly depressed behind scarcely impressed frontal sulcus.
Collecting data: Collected from October to February in valdivian rainforest at elevations ranging from 310 m to 580 m. All specimens came from sifted samples of leaf and log litter, except for one male collected by car net.
Distribution: The species is known only from the Los Lagos Región (southern Chile) (Fig. 83: blue triangles).
Comments: The males of A. denticornis are easily distinguished from the other species of the A. grandiceps group by the shape of their mesotibiae (Fig. 44). The form of their head (Figs 71-74), antennae (Fig. 16), protibiae (Fig. 38), and aedeagus (Figs 7-8) are also diagnostic. The females of this species are characterized by their large head with the frons shallowly depressed behind the barely impressed frontal sulcus, antennomeres III-IV are longer than wide, antennomere V is distinctly longer than wide and is longer than all other antennomeres of the funicle. Medial margin of antennomere V slightly widened in the distal third. Jeannel (1962: 423) claims that the antennomeres V of the female of A. denticornis possess a small tubercle with two bristles, but we did’nt found this feature in all the females examined.
In the original description Jeannel (1962: 423) mentions that this species was described from 50 specimens collected by Kuschel in Chepu on 3.X.1958. Howewer, upon examination of the type series of Kuschel for the dates indicated by Jeannel we found only 25 specimens (holotype and paratypes). Two other males of the typical series, that are housed in MNHN, were collected by Kuschel in Chepu and are labeled as paratypes, but were collected on different dates (i.e. 1 male paratypes on 04.X.1958; and 1 male paratypes on 11.X.1958), a detail most likely overlooked by Jeannel.
description: 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 137-139, DOI: 10.35929/RSZ.0013, http://zenodo.org/record/5743391