Achilia bifrons Jeannel, 1962

Kurbatov, Sergey A., Cuccodoro, Giulio & Sabella, Giorgio, 2021, A revision of the Chilean Brachyglutini - Part 7. Revision of Achilia Reitter, 1890: A. cosmoptera species group (Coleoptera: Staphylinidae: Pselaphinae), Revue suisse de Zoologie 128 (1), pp. 135-156 : 138-139

publication ID	https://doi.org/ 10.35929/RSZ.0041
DOI	https://doi.org/10.5281/zenodo.5645634
persistent identifier	https://treatment.plazi.org/id/5F215668-FFD4-FF94-E6EF-FA4D81CC5951
treatment provided by	Felipe
scientific name	Achilia bifrons Jeannel, 1962
status

Treatment

Achilia bifrons Jeannel, 1962 View in CoL

Figs 5 View Figs 1-6 , 18 View Figs 16-22 , 37 View Figs 37-42 , 39 View Figs 37-42 , 41 View Figs 37-42 , 63 View Fig

Achilia bifrons Jeannel, 1962: 426 View in CoL , 428, fig. 192 (aedeagus).

Type material (2 ex.): CENTRAL CHILE: Región Bío Bío: Concepción Prov.: MHHN; 1 ♂ (Lectotype, here designated) labels verbatim “Lectotype / Boca del Biobio / Concepcion; 26.V.1957 / Achillia bifrons (handwritten by Jeannel) ” . – MNHN, 1 ♂ (Paralectotype, here designated); labels verbatim “Paralectotype / El Caracol; Conc.; 26.V.1957 / 2 Fb” .

Additional material examined (4 ex.): CENTRAL CHILE: Región Bío Bío: Concepción Prov.: MSNG; 1 ♂ and 1 ♀; Lomas Coloradas ; 21.V.1988; site TC- 208; T. Cekalovic. – MHNG; 1 ♂ and 1 ♀; same data .

Description: Body 1.55-1.60 mm long, entirely reddish with slightly darkened abdomen; palpi yellowish.

Male: Head as in Figs 37, 39 & 41 View Figs 37-42 , wide, surface with scattered punctures; occipital region and basal half of frons raised with U-shaped median notch; basal half of frons very long and convex, and separated from distal half of frons by transverse sulcus; anterior margin of this sulcus raised and pointed at middle, bearing tuft of long setae. Antennae ( Fig. 18 View Figs 16-22 ) with scape and pedicel longer than wide; antennomeres III-IV slightly longer than wide; antennomeres V-VII longer than wide; antennomere VIII about as long as wide; antennomere IX only slightly wider than VIII and slightly wider than long; antennomere X wider than long and wider than IX; antennomere XI elongate, about as long as VII-X combined. Metaventrite with wide medial sulcus on apical on two-thirds, sulcus densely pubescent. Mesotibiae with distal half swollen and densely pubescent. Aedeagus ( Fig. 5 View Figs 1-6 ) 0.31-0.32 mm long, with subrectangular dorsal plate slightly narrowed apically; dorsal longitudinal struts slightly divergent. Parameres relatively wide with large and long recurved seta on well-developed and relatively long outer lobe; apical portion of parameres slightly recurved anteriorly; apex bearing one ventral medial seta. Copulatory pieces consisting of two subequal bifid sclerites basally recurved and more robust, topped with medial sclerites with rounded apical sides.

Female: Similar to male except head not modified; antennae shorter; eyes smaller; metaventrite, and legs unmodified.

Collecting data: The data in our possession do not allow statements in this regard other than members of this species are active in May.

Distribution: Achilia bifrons is only known from Concepción Province (Región Bío Bío) ( Fig. 63 View Fig : blue inverted triangles).

Comments: Jeannel (1962: 428) described A. bifrons on the basis of two males collected in Concepción Province, respectively at Bocas del Biobio and at Cerro Caracol. He stated that the holotype of A. bifrons was housed in the MNHS and the paratype in the MNHN. However in the MNHS we couldn’t find any specimens of A. bifrons , and moreover this taxon is not listed in the catalog of the MHNS holotypes of insects ( Camousseight, 1980). Instead we found in the MNHN two males of this species identified as such by Jeannel and labeled as from Bocas del Biobio and Cerro Caracol , but not bearing any type labels. Considering that Jeannel (1962: 428) indicated the type locality as generically from Concepción , we designate here the male labeled “Boca del Biobio / Concepcion; 26.V.1957 / Achillia bifrons (handwritten by Jeannel)” as the lectotype of A. bifrons , and the other male from Cerro Caracol as paralectotype.

The males of A. bifrons are easily distinguished from other species of the A. cosmoptera group by the shape of the head ( Figs 37, 39, 41 View Figs 37-42 ), antennae ( Fig. 18 View Figs 16-22 ), and aedeagus ( Fig. 5 View Figs 1-6 ). The females of this species are similar to those of A. temporalis from which they can be easily distinguished by their very long frontal lobe with the anterior margin slightly pointed at the middle, while the frontal lobe is short with a straight anterior margin in A. temporalis .