Philonthus rubromaculatus Blanchard, 1842

Chani-Posse, Mariana, 2010, Revision of the southern South American species of Philonthus Stephens (Coleoptera: Staphylinidae) 2595, Zootaxa 2595, pp. 1-70 : 49-50

Philonthus rubromaculatus Blanchard, 1842

( Figs. 116–120, 148)

Philonthus rubromaculatus Blanchard, 1842: 82 ; Lynch-Arribálzaga, 1884: 151 (characters, Argentina); Bernhauer & Schubert, 1914: 353 (catalog); Bruch, 1915: 445 (catalog); Scheerpeltz, 1933: 1359 (catalog); Blackwelder, 1944: 134 (list); Herman, 2001b: 2944 (catalog); Chani-Posse, 2004: 231 (list).

Diagnosis. Philonthus rubromaculatus may be identified by its body coloration and the antennal segments 4– 8 elongate and 9–10 quadrate. It differs from other southern South American species of Philonthus by the first segment of hind tarsus as long as to slightly shorter than last segment, and the shape of aedeagus.

Redescription. Length of the body 5.9–6.6 mm. Coloration. Head and thorax black; elytra black to piceous-black at base and medial margins, rest of elytra reddish; abdomen piceous-black; antennae, palpi and legs castaneous-piceous.

Head slightly wider than long (HW/HL= 1.1) and at basal third as wide as at distal third, as wide as to slightly narrower than pronotum (HW/PW= 0.97–0.84); dorsal surface coarsely and moderately punctate, with no more than three postocular punctures and three to five epicranial punctures; distance separating medial interocular punctures on frons less than twice as large as distance separating medial punctures from lateral punctures; infraorbital ridge present, not extending beyond postgenal ridge. Eyes about as long as to slightly longer than temples (EL/TL= 1.20–0.88) seen from above. Antennae with segment 1 distinctly shorter than segments 2 and 3 combined, segments 2 and 3 subequal in length, 4–8 elongate, 9–10 quadrate. Labial palpus with last segment about 1.5 times as long as preceding segment. Maxillary palpus with last segment about 1. 5 times longer than segment 3. Submentum and mentum subequal in length. Neck no more than 0.6 times as wide as head at widest point (NW/HW= 0.6).

Pronotum as long as wide to slightly longer than wide (PW/PL= 1.0–0.87), slightly narrowed anteriad; dorsal surface of pronotum with two rows of punctures, each with six punctures. Hypomeron not visible in lateral view. Basisternum with medial longitudinal carina weakly developed. Metasternum with circummesocoxal ridge broadly rounded medially. Elytra at sides distinctly longer than pronotum at midline (EtL/ PL=1.6–1.5), about 1.5 times as long as elytra along suture (EtL/Etl= 1.7), and longer than wide at base of elytra (EtL/EtW=1.2–1.1); transverse distance between punctures about as large as diameters of punctures. Front and middle tarsi as long as front and middle tibiae; first segment of hind tarsus as long as segments 2 and 3 combined, and as long as to slightly shorter than last segment (S1/S5= 1.0–0.8). Abdominal terga coarsely punctuate at basal area, distance separating punctures distinctly smaller than diameters of punctures; terga 2 and 3 with elevated area between basal lines punctuate, posterior basal line straight medially. Male sternum 7 with apical margin slightly notched at middle. Tergum 8 in both sexes with posterior margin truncate.

Male genitalia. Sternum 8 moderately emarginate medio-apically ( Fig. 116). Tergum 10 wide and subangulate to arcuate medio-apically ( Fig. 119), with two long subapical macrosetae and 8–10 apical setae. Sternum 9 acutely emarginate apically with two long subapical macrosetae and two apical setae at each side ( Fig. 117). Aedeagus with median lobe gradually narrowed from apical third; apex of median lobe subrectangular (in dorsal view); paramere reduced and fused to median lobe ( Fig. 118). Internal sac with sclerotized structures.

Female genitalia. Tergum 10 similar to that of male, with four long subapical setae and 5–6 apical setae. Second gonocoxite with more than five strong setae along its outer margin, and stylus with two apical setae ( Fig. 120).

Bionomics. Blanchard (1842) reports this species to occur in dry and arid environments, under dried cow manure.

Geographical distribution. P. rubromaculatus is currently known from the biogeographic provinces of Puna in northern Argentina (one record), Pampa (central Argentina and Uruguay) and the Magallanic Paramo in southern Chile ( Fig. 148).

Type material. Lectotype (here designated; Figs.), ♂, with labels: “5528/ 34” (round green label; old handwriting on its underside), “ Philonthus rubromaculatus ” (white label; modern handwriting), “ Lectotype Philonthus rubromaculatus Blanchard, 1842 / Des. Chani-Posse de Maus 2009 ” (MNHN). Paralectotype, ♀, same labels as the lectotype, with additional label: “ Paralectotype Philonthus rubromaculatus Blanchard, 1842 / Des. Chani-Posse de Maus 2009 ” (MNHN).

Notes. In the original description of P. rubromaculatus ( Blanchard 1842) there is no indication about the number of specimens included in the type series. Both specimens listed in the type material agree with the description by Blanchard (1842). The male specimen is designated as the lectotype.

Before the present designation, some research had to be done in order to confirm the status of these specimens as type material of P. rubromaculatus . With the help of Ms. Taghavian (MNHN), I was able to establish a correspondence between the numbers given on the round green label and those detailed by Blanchard in the catalog d´Orbigny at the MNHN. Additional locality data was found by Ms. Taghavian at the site in the box to which these specimens belong. This information agrees with the original description (Montevideo). Therefore, I conclude that these specimens belong to the type material that Blanchard (1842) used in the original description of P. rubromaculatus .

Additional material: 30 specimens (6 ♂, 6 ♀, 18 unsexed)

ARGENTINA: Buenos Aires, Hurlingham , I.1956, 1 ♂, 3 ♀ ( FMNH) ; La Plata, Brewer , Philonthus rubromaculatus Blanchard , 1 specimen ( CEUNC) ; Tigre, 6-1938, M. J. Viana, in Bernhauer handwriting " rubromaculatus Blch. Don. M. J. Viana "/ 66, in Bernhauer hanwriting " Philonthus rubromaculatus Bln. ",, det. Bernhauer; Chicago NHMus Bernhauer Collection, 1 ♂ ( FMNH) , 2 specimens ( MLPA) ; 190, C. Bruch, " Philonthus rubromaculatus Blanch. ", Chicago NHMus Bernhauer Collection 1 specimen ( FMNH) , 1 specimen ( MACN) ; 5.12.1900 / 4.IX.1911, C. Bruch, 2 specimens ( MACN) , 2 specimens ( NMPC) ; 4.XII.1897, C. Bruch, Philonthus rubromaculatus Blanch. , 1 specimen ( CEUNC) . Catamarca: 5km N de Belen , 19/X/97, S. Roig, 1 specimen ( IADIZA) . Córdoba: Manfredi , 27-VIII-1973 / 31-X-1973, Brewer, 1 ♂, 2 specimens ( CEUNC) . CHILE: Punta Arenas : Dic 1962, PJDarlington, 1 ♂, 1 ♀ ( MCZ) . URUGUAY: Montevideo: 12.III.07/ 10.I.1933, J. Tremoleras, in Bernhauer handwriting " rubromaculatus Blanch. det. Bernhauer ", Chicago NHMus Bernhauer Collection, 2 ♂, 2 ♀, 4 specimens ( FMNH) ;; 13.XI.1906, Philonthus rubromaculatus Blanch. , 1 specimen ( MACN) .