Faronus rica, Kurbatov & Mifsud & Sabella, 2019

Kurbatov, Sergey A., Mifsud, David & Sabella, Giorgio, 2019, A new species of Faronus Aubé, 1844, endemic to Malta (Coleoptera, Staphylinidae, Pselaphinae), Zootaxa 4571 (3), pp. 417-422 : 418-420

Faronus rica sp. nov.

( Figs 1, 2 , 5 , 7, 9, 11 )

Type material. Holotype , ♂ (MHNG). MALTA, Wied Babu , 50 m, 23.xi.2017, sifting litter of Ceratonia siliqua (S. Kurbatov). Paratype, 1 ♀ ( MHNG); same locality of holotype, 24.xi.2017, sifting litter of Ceratonia siliqua (D. Mifsud & G. Sabella) .

Description. Male. Body length 1.75 mm, entirely reddish brown with yellowish palpi and legs. Relatively dense pubescence of long and flattened golden setae on head, pronotum, elytra and abdomen; other setae, yellowish and suberect present on sides of antennae, palpi and legs. Tegument smooth and shiny.

Head triangular, wider (0.35 mm) than long (0.22 mm). Wide and deep longitudinal median frontal sulcus, which starts from the frontal lobe and forks in the middle; then bifurcates towards the base of the occipital region. Temples slightly shorter than eyes and marginally protruding, each forming an angle of about 70° with the longitudinal axis of the head, and ending in an annular organ. Eyes well developed and protruding with 32-33 facets. Antennae with cylindrical scape about twice as long as wide, pedicel as long as wide, antennomere 3 is the smallest of the flagellum and wider than long, antennomere 4 slightly longer than wide, antennomeres 5-6 as long as wide, antennomeres 7-8 slightly wider than long. The club is not so distinct having antennomeres 9-10 wider than long and wider than preceding articles; antennomere 11 slightly wider than 10 and slightly longer than wide.

Pronotum distinctly wider (0.41 mm) than long (0.31 mm), widest in the middle; lateral discal fovea, lateral antebasal fovea, medial antebasal fovea, and outer antebasal fovea present and distinct; antebasal sulcus lacking. Disc convex in the middle with a horseshoe-shaped impression, its transversal part (including the median antebasal fovea) distinctly impressed whereas the two longitudinal branches very weakly impressed; the latter bearing four adjacent foveae.

Elytra wider (0.51 mm) than long (0. 40 mm) and longer than pronotum, and gradually widen from the base to the apex. Two basal foveae; sutural stria reaching apical part of elytra with three very small adjacent foveae; discal stria reaching about two thirds of elytral length. Humeri not distinctly protruding followed by a weak lateral depression. Hind wings absent.

Abdomen distinctly longer than both pronotum and elytra together, the first three visible tergites having the same length. Posterior margin of 2 nd ventrite slightly raised in the middle; posterior margin of 3 rd ventrite strongly raised and forming an open cup-shaped structure in the middle ( Fig. 1 ); the central part of the 4 th ventrite depressed having the middle part of posterior margin raised as a form of lamina at 90° in such a way that it fits into the cupshaped structure just described and apically slightly curved posteriorly ( Fig. 2 ).

Legs with protibia widest in the middle ( Fig. 9 ) with mesal margin sinuate in distal half, apically having a short rounded process; mesotibiae slightly enlarged in the apical third with a similar terminal process as in the protibiae.

Aedeagus ( Fig. 7 ) length 0.33 mm, with well-developed slender parameres widest in the middle, left paramere with two apical setae and right paramere with one; two additional medial setae are also present towards the centre of each paramere. Median part of aedeagus wide and distinctly sclerotized with a pointed apical part on the right; apical membrane equipped with multiple small spiniform processes.

Female. Body ( Fig. 5 ) length 1.80 mm entirely light reddish with yellow palpi and legs. Pubescence and tegument as in male.

Head as in male, wider (0.31 mm) than long (0.21 mm). Eyes well developed and protruding with 25–27 facets. Antennae similar to those of male.

Pronotum similar to that of male, also for the foveae system on dorsal surface, wider (0.36 mm) than long (0.31 mm).

Elytra wider (0.44 mm) than long (0.33 mm), similar to those of male, only less distinctly enlarged from base to apex.

Abdomen as in male in dorsal view, and with unmodified abdominal ventrites.

Legs unmodified.

Telisternite as in figure 11.

Comparative notes. Faronus rica sp. nov. belongs to the F. hispanus species group ( Sabella 1993) characterized by males having secondary sexual characters on abdominal ventrites, aedeagus with sinuate parameres, well sclerotized median part bearing multiple small spiniform processes apically. The group currently accommodates F. hispanus Saulcy, 1870 , known from Portugal (Algarve), Spain (Catalonia, Valencia, Andalusia) and northern Algeria; F. insularis Sainte-Claire Deville, 1908 , endemic to Sardinia and circum-sardinian islands and southern Corsica; F. siculus Fiori, 1913 , endemic to Sicily, F. insignis Besuchet, 1958 , known from the Balearic Islands (Majorca and Minorca), and F. rica sp. nov. endemic to Malta.

Faronus rica sp. nov. is closely related to F. siculus with which many morphological characters are shared. It differs from this species on the basis of the following features: (i) protibia of male widest in the middle with mesal margin sinuate in distal half (cfr. Figs. 9, 10 ); (ii) left side of median part of aedeagus pointed apically (cfr. Figs. 7, 8 ); and (iii) the highly modified 3 rd and 4 th ventrites having a strongly raised open cup-shaped structure in the middle (on 3 rd ventrite) and a 90° raised lamina (on 4 th ventrite) which fits into the cup-shaped structure and apically curved posteriorly (cfr. Figs.1-4 ). Females of both species are impossible to discriminate on the basis of morphological features. Some morphological differences in the apical region of the telisternite were found and these are illustrated in figures 11 and 12.

Ecological notes. The two specimens of Faronus rica sp. nov. were collected in November by sifting leaf litter under Ceratonia siliqua, in a valley system at 50 m of altitude, along with numerous specimens of Tychus opuntiae (Schmidt-Goebel, 1836) . Wied Babu ( Fig. 6 ) is a fine example of a river valley and creek. The area is rich in endemic species such as the National Plant for Malta ( Cheirolophus crassifolius ) for which Wied Babu is the type locality.

Etymology. This species is dedicated to Yves and Patricia Rica, a French family residing in Malta who are always very helpful and contribute financially for entomological research work carried out by the corresponding author in Malta. They offered free accommodation to many delegates present at the 4 th International Congress of Biodiversity held in Malta (13-16 th November 2017) and thereafter, this provided the right opportunity for the present authors to do intensive field work and to discover the new species which we gladly and proudly dedicate to them.

Figures

FIGURES 1–4. Abdominal ventrites (dorsal and lateral view): 1, 2—Faronus rica sp. nov.; 3, 4—F. siculus.

FIGURES 5–6. 5—Habitus of female, Faronus rica sp. nov.; 6—Wied Babu, type locality of F. rica sp. nov.

FIGURES 7–12. 7, 8—Aedeagi; 9, 10—protibiae of males; 11, 12—female telisternites. (7, 9, 11— Faronus rica sp. nov.; 8, 10, 12—Faronus siculus)