Domene (Lathromene) viriatoi Serrano & Boieiro

Serrano, Artur R. M., Conde, José, Antunes, Sandra, Aguiar, Carlos A. S. & Boieiro, Mário, 2015, A new species of Domene Fauvel, 1873 (Coleoptera: Staphylinidae: Paederinae) from a granitic cavity in Serra da Estrela (Portugal), Zootaxa 3974 (3), pp. 401-412 : 403-409

Domene (Lathromene) viriatoi Serrano & Boieiro , new species

( Figs 2 , 3 , 4, 5 , 6 , 7 )

Type material: Holotype, ♂, Portugal, Buraco da Moura (Lapa dos Dinheiros) (U.T.M. coordinate: 29TPE103714), 13‒24.X.2014, (J. Conde, M. Boieiro & S. Antunes leg.). Paratypes, same locality of holotype, 1 ♂, 7‒31.X.2013, 1♂, 19.VII‒17.VIII.2014, (J. Conde & S. Antunes leg.), 2♂ (1♂ gold coated), 13.X.2014, 3♀, 13‒24.X.2014, (J. Conde, M. Boieiro & S. Antunes leg.). The holotype and paratypes are deposited in the collection of the first author, at Departamento de Biologia Animal (Faculdade de Ciências da Universidade de Lisboa).

Etymology. The new species is dedicated to Viriato known as a Benefactor and Savior by the Lusitanians. He was originally from the high Montes Hermínios, nowadays Serra da Estrela, and, according to some theories, he became a soldier after being shepherd and a huntsman. Viriato is known as the greatest military leader of the Lusitanians, having won many battles against the Roman occupation being named after this “ Terror romanorum ”.

Description. Microphtalmous, wingless and elongate body ( Fig. 2 ). Coloration: body reddish and abdomen dark-reddish. Body length: 6.9‒8.2 mm (males), 6.3‒8.8 mm (females).

Head ( Figs 3 a, 4): subquadrate/orbicular, 1.1 times longer than wide (males and females) [length: 1.22‒1.26 mm (males) and 1.15‒1.31 mm (females), width: 1.10‒1.18 mm (males) and 1.10‒1.20 mm (females)], slightly wider than pronotum (1.1‒1.2 times); eyes reduced, with about 22 ommatidia ( Fig. 3 b); long and thin seta in a supraocular, small circular depression; a patch of yellowish minor pubescence above the depression and behind the eyes ( Fig. 3 b); two dark spots in the vertex signal the insertions of the dorsal arms of the tentorium; gular sutures well defined, converging towards neck ( Fig. 4); dorsal surface without any isodiametric microreticulation, with well-defined dense punctuation, similar to that of pronotum, on lateral sides and behind vertex; vertex and front with sparse punctuation, almost smooth ( Fig. 3 a); antennae filiform ( Fig. 3 d), 2.7 mm long, reaching the base of pronotum when directed backwards; all antennomeres longer than wide, the 1st longest of all [length: 1.13‒1.25 mm (males) and 1.21‒1.29 mm (females)]; 3rd antennomere in average 1.2-1.3 times longer than the 4th and 5th antennomeres; the 6th to 10th antennomeres are subequal and the 11th is 1.3‒1.4 times longer than the five precedents; labrum deeply emarginated with 9‒11 large setae spread over the disk and the anterior margin ( Fig. 3 c); mandibles symmetrical with four distinct teeth in the inner edge, two of them are more pronounced ( Fig. 4); maxillary palpus with four articles, second and third subequal, more than 3 times as long as broad, apical joint reduced and conical; internal lobe of maxilla with clusters of setae; labium with bilobed glossae, circumscribed by hairy paraglossae; labial palpus with three joints, the 2nd being the longest and more robust, and the 3rd the thinnest.

Pronotum ( Fig. 3 g): 1.3 times longer than wide (males and females) [length: 1.23‒1.31 mm (males) and 1.22‒1.34 mm (females), width: 0.98‒1.04 mm (males) and 0.94‒1.07 mm (females)], slightly narrower than head, widest anteriorly and distinctly tapering posteriad; anterior angles weakened, posterior angles marked but largely obtuse; basal margin well defined; punctuation similar to that of head, evenly distributed except for a smooth midline ranging from the anterior to the posterior parts; absence of any middle sulcus, interstices without microsculpture.

Elytra ( Fig. 3 h): 1.2 times wider than long [length: 0.74‒0.82 mm (males) and 0.75‒0.83 mm (females), width: 0.93‒0.97 mm (males) and 0.88‒0.99 mm (females)], approximately 0.6 times shorter than head or pronotum [average elytra length/head length: 0.63 (males and females), average elytra length/pronotum length: 0.61 (males) and 0.62 (females)]; only slightly narrower than head (males and females: 0.8 times) or pronotum (males: 0.9 times, females: 1.0); flat in dorsal view; humeral angles obsolete; lateral margins slightly divergent posteriad; surface with coarse, rugose and wrinkled punctuation. Wingless.

Abdomen ( Figs 5 , 6 ): Maximum width at segment VI, approximately 1.3 times wider than elytra; tergites IV‒VI with fine and dense punctuation within a microsculpture of transverse meshes, these more pronounced in the intersegmental membranes; sternite III (males and females) with a middle carina in the first two thirds surrounded in both sides by a small depression to accommodate the resting metacoxae, another minor carina in the middle of the posterior intersegmental membrane ( Fig.5 a); sternites III‒VI with fine and dense punctuation within a microsculpture of transverse meshes, substituted by irregular rows of scale-shaped microtrichia anteriad near the intersegmental membranes and by regular posteriad quadrate meshes (e.g. Fig. 5 b). Male: sternite VII with shallow median impression of triangular shape posteriorly, with some lateral scattered short, and stout striated setae, some of them black (2‒5), interspersed among normal setae ( Fig. 5 c); sternite VIII transverse, anteriorly with shallow median impression of semicircular shape, posteriorly with a distinct incision in an inverted U‒shaped surrounded by a small glabrous area with a microsculpture of transverse meshes; on either side of the apex of this impression there is a cluster of 15‒21 modified, short and stout black striated setae ( Figs 5 e‒5f, 6a), looking like a brush; sternite IX slightly arcuate apically; genital segment in ventral view as in figure 6a. Female: genital segment (dorsal view) with a large glabrous area in the center and in ventral view as in figure 6b.

Legs: Long and slender; forelegs with antennal cleaning organ following the general pattern of the genus ( Figs 3 e‒3f).

Aedeagus ( Fig. 7 ): Sclerotized ventral blade exceeding largely the edge of the aedeagus ( Fig. 7 a), with a straight apex, slightly truncate in the middle, in each side with a small tooth, and a small lateral tooth‒shaped expansion in midway between the apex and the base ( Fig. 7 a); fused lateral lobes ( Fig. 7 c); ellipse‒shaped in dorsal view, presenting a V‒shaped sclerotized blade covering the upper part and the apical edge of the aedeagus ( Fig. 7 b); median lobe with two internal small finger‒like structures and one plate of scale in each side ( Figs 7 a‒7b).

Taxonomic remarks. According to the taxonomic criteria defined by Coiffait (1982), Domene viriatoi n. sp. should be included in the subgenus Lathromene . The species shows distinctive morphological characteristics from the other congeners of this subgenus, namely the shape of the aedeagus and the characters of the male sternite VIII. Taking into account the pieces of aedeagus, the new species can be easily segregated from D. scopaeella , D. subiasi (Outerelo, 1977) , D. gallaeciana Feldmann & Hernando, 2005 and D. barraganensis Outerelo & Gamarra, 2012 , by the symmetry type of ventral blade (symmetric in the new species vs. asymmetric in the other four species). Among the species with symmetric ventral blade, the closest species to D. viriatoi n. sp. seem to be D. lusitanica Reboleira & Oromi, 2011 and D. caurelensis Outerelo, Gamarra & Salgado, 2000 . However, unlike the new species, the ventral blade in D. lusitanica does not exceed the edge of the aedeagus, presents a pointed apex and lacks the minor middle lateral hook-like expansions between the apex and base (cf. Figs 7 a‒7c and Fig. 6 in Reboleira et al. 2011b). On the other hand, the ventral blade of D. caurelensis only exceeds slightly the edge of the aedeagus, the apex is strongly bifurcated and the minor middle lateral hook-like expansions are also absent (cf. Figs 5 a‒5c and Fig. 7 in Outerelo et al. 2000).

Furthermore, the differences concerning the male sternite VIII between the new species and its closest relatives are even more evident. Domene viriatoi n. sp. exhibits posteriorly a distinct inverted U‒shaped incision with a cluster of 15‒21 modified, short and stout black striated setae on either side of the apex ( Figs 5 e, 6a). The other two species, although presenting a posterior incision, it is not so pronounced as in the new species and lack short and stout black striated setae. Interestingly, some representatives of Domene (s. str.), like D. gevia Hernando & Baena, 2006 and D. perezi Assing, 2012 , present a pair of clusters of stout setae in sternite VIII also, but near the base or along the edges of the inverted U or V‒shaped incision.

The congeners with populations closer to the new species are D. lusitanica (from Serra de Sicó, Portugal) and D. hispanica Outerelo, 1985 (from Peña de Francia, Spain). The latter species, which male is unknown, can be segregated from D. viriatoi n. sp. by the presence of a pronotal sulcus in the posteriad middle region (absent in the new species), the flattening of the posterior region of pronotum (in D. viriatoi n. sp. is slightly convex) and the elytral length (equal to pronotum in D. hispanica and smaller than pronotum in D. viriatoi n. sp.). Moreover, the number of ommatidia in D. hispanica is 15 (Outerelo 1985), much less than in D. viriatoi n. sp. ( Fig. 3 b).

The morphological resemblance between some species of Domene and Lathromene subgenera (e.g. shape and presence of stout setae in the sternite VIII incision) shows how controversial these supraspecific taxonomic entities are. Nevertheless, although practical, the subgeneric classification of genus Domene is at present highly artificial and in urgent need for revision following a comprehensive phylogenetic analysis ( Assing & Feldmann 2014). However, this task is out of the scope of the present work.

Figures

FIGURE 2. Domene viriatoi n. sp. adult.

FIGURE 3. SEM photographs of structural features of Domene viriatoi n. sp.: (a), head (dorsal view); (b), detail of the eye and chaetotaxy (lateral view); (c), labrum (dorsal view); (d), antennae (dorsal view); (e), part of the cleaning organ in foretibia (latero ‒ ventral view); (f), part of the cleaning organ in forefemur (latero ‒ ventral view); (g), pronotum (dorsal view); (h), elytra (dorsal view).

FIGURE 5. SEM photographs of structural features of Domene viriatoi n. sp.: (a), III abdominal sternite (latero ‒ ventral view); (b), detail of intersegmental area between III and IV abdominal sternites (latero ‒ ventral view); (c), VII, VIII and IX abdominal sternites (ventral view); (d), detail of middle posteriad region of VII abdominal sternite (male, ventral view); (e), detail of VIII abdominal sternite (male, ventral view); (f), detail of the cluster of stout striate setae in VIII abdominal sternite (ventral view).

FIGURE 6. Genital segment of Domene viriatoi n. sp. (ventral view): (a), male; (b), female.

FIGURE 7. Aedeagus of Domene viriatoi n. sp.: (a), lateral view; (b), dorsal view; (c), ventral view.