Philonthus longicornis Stephens, 1832

Chani-Posse, Mariana, 2010, Revision of the southern South American species of Philonthus Stephens (Coleoptera: Staphylinidae) 2595, Zootaxa 2595, pp. 1-70 : 35-38

Philonthus longicornis Stephens, 1832

( Figs. 87–91, 150; Figs. 331–338 in Smetana 1995)

Philonthus longicornis Stephens, 1832: 237 . For complete references see Herman (2001b).

Philonthus perplexus Fairmaire & Germain, 1861: 431 ; Fauvel, 1866a: 345 (= 1866b: 96) (misidentified as varians according to Coiffait & Sáiz, 1968: 360; characters); Fauvel, 1869: 489 (syn. of longicornis ); Fauvel, 1874a: 255 (= 1874b: 481) (syn. of longicornis ); Ganglbauer, 1895: 454 (syn. of longicornis); Bernhauer & Schubert, 1914: 345 (catalog; syn. of longicornis ); Blackwelder, 1943: 410 (syn. of longicornis ); Smetana, 1958: 189 (syn. of longicornis ); Coiffait & Sáiz, 1968: 360 ( Spatulonthus ; valid species; characters); Sáiz, 1971: 348 ( Spatulonthus ; notes); Desender & Baert, 1996: 36 ( Spatulonthus ; list); Herman, 2001b: 2911 (complete references). Chani-Posse, 2004: 231 (list); Chani-Posse de Maus 2009: 37 (syn.).

Diagnosis. Philonthus longicornis may be identified by the infraorbital ridge present, reaching postgenal ridge and the paramere shifted toward right margin of median lobe. It differs from P. aeruginosus by the eyes about as long as to slightly longer than temples, and the antennal segment 2 shorter than preceding segment.

Redescription. Length of the body 6.8–7.5 mm. Coloration. Head black; thorax, elytra and abdomen piceous-black; antennae, palpi and legs castaneous-piceous.

Head about as long as wide to slightly longer than wide (HW/HL= 1.0–0.9) and at basal third as wide as distal third in both sexes, distinctly narrower than pronotum (HW/PW= 0.76–0.70); dorsal surface coarsely and moderately punctate, with three to four postocular punctures and three to four 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, reaching postgenal ridge. Eyes about as long as to slightly longer than temples (EL/TL= 1.2–1.1) seen from above. Antennae with segment 1 slightly shorter than segments 2 and 3 combined, segment 2 shorter than preceding segment, segments 4–10 elongate. Maxillary palpus with segment 2 not swollen, no more than twice as long as its maximum width; last segment fusiform, about 1.5 times longer than segment 3. Submentum and mentum subequal in length. Labial palpus with last segment twice as long as preceding segment. Neck more than 0.5 times as wide as head at widest point (NW/HW= 0.7).

Pronotum about as long as wide (PW/PL= 1.05–1.00), distinctly narrowed anteriad; dorsal surface of pronotum with two rows of punctures, each with five punctures. Hypomeron not visible in lateral view. Basisternum with medial longitudinal carina moderately developed, bulbous. Metasternum with circummesocoxal ridge broadly rounded medially. Elytra at sides moderately to distinctly longer than pronotum at midline (EtL/PL=1.4–1.2), distinctly longer than elytra along suture (EtL/Etl= 1.8–1.6); transverse distance between punctures about as large as to distinctly smaller than diameters of punctures. Front tarsi as long as front tibiae; mid tarsi longer than mid tibiae; first segment of hind tarsus as long as segments 2 and 3 combined, and longer than last segment (S1/S5= 1.4). Abdominal terga distinctly 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 apically. Tergum 8 in both sexes with posterior margin truncate.

Male genitalia. Sternum 8 moderately emarginate medio-apically. Tergum 10 wide and subangulate medio–apically ( Fig. 88), with four long subapical macrosetae and 2–6 apical setae. Sternum 9 deeply emarginate apically with basal portion asymmetrical, two long subapical macrosetae and two apical setae at each side ( Fig. 87). Aedeagus with median lobe gradually narrowed from base of paramere and enlarged near apex; apex of median lobe arcuate (in dorsal view) and simple in its apical fourth (in lateral view); paramere elongate and entire, rod-like, reaching two thirds of median lobe length, with two lateral rows of sensory peg setae joined at apex, each with four sensory peg setae ( Fig. 90), and shifted toward right margin of median lobe. Internal sac with sclerotized structures ( Fig. 89).

Female genitalia. Tergum 10 acute apically, with 5–6 apical setae. Second gonocoxite with 2–5 strong setae along its outer margin, and stylus with two long apical setae ( Fig. 91).

Bionomics. Philonthus longicornis has been reported as a common visitor of cattle manure in open pastures of North America ( Hu & Frank 1997) and Argentina (Chani-Posse 2004). Smetana (1995) also cited it from other organic debris such as decaying plants, other animal droppings, carcasses, etc. This species, like P. flavolimbatus and P. hepaticus , has been shown as an important predator of dung-breeding flies in North America ( Hu & Frank 1997).

Geographical distribution. Philonthus longicornis is currently considered a cosmopolitan species ( Herman 2001b) of Palaearctic origin ( Smetana 1995). According to the records ( Herman 2001b; Newton & Thayer 2005) and the material studied, P. longicornis is widely distributed in Central and South America. In southern South Argentina, it occurs from the Chacoan subregion to the Subantactic subregion ( Fig. 150).

Type material. Stephens (1832: 237) described the species from specimens from London. I have not seen the original material but there is little doubt that this species, as interpreted later by other authors (e.g. Smetana 1995), is the species that Stephens described.

Additional material: 62 specimens (5 ♂, 4 ♀, 53 unsexed)

ARGENTINA: Catamarca: 20.I.1912, C. Bruch (1 FMNH, 1 MACN) . Cordoba, Manfredi , 2-IX-1971 / VIII.1973, Brewer, 4 specimens ( CEUNC) . Mendoza: Alvarez Condarco , III.79, Sergio Roig, 1 specimen ( IADIZA) ; Dorrego , Enero 1977, Sergio Roig, 1 specimen ( IADIZA) ; Godoy Cruz , XII.79, Sergio Roig, 1

specimen ( IADIZA); Malargue , a 7km de Ranquil Norte, camino a Barrancas, 24-I-79, 1 specimen ( IADIZA) . San Juan : El Encon, 18-I-1982, A. Roig, 1 specimen ( IADIZA) ; Las Tumanas , 13–14.IV.79, Sergio Roig, 1 specimen ( IADIZA) . Tucumán: El Cadillal, 22.VI.1998, col. M. Chani Posse, 3 ♂, 2 ♀ ( IMLA) . Buenos Aires: Argentina, Prov. Buenos Aires , Castelar , 29 December 1989, in cow dung, coll. G. Cabrera, code: dung-175, 1 ♂ ( MLPA) ; 19.XII.1911, C. Bruch 2 specimens ( MACN) , 2 specimens ( MLPA) ; Richter , 12 specimens ( MLPA) ; Flores , 7.VII. 1915, 2 specimens ( MLPA) ; 9km W El Infiernillo , 7-XII-03, G. Flores, 2700m, 26° 47' 33.5''S, 65° 43' 40.6''W, 1 specimen ( IADIZA) . BOLIVIA: Río Longo , 1 specimen ( FMNH) . BRAZIL: Sao Paulo: Braz. Mraz., Mus. Praguense, 9 specimens ( FMNH) . CHILE: Cautín: Vilcún, Pte Lan-Lan 1, 28 mar 2006, fogging Nothofagus dombeyi , 1 ♀, (Col. J. E. Barriga) ; Maipo , 12-XI-1972, Col. G. Arriagada, 1 ♂, 1 ♀ ( MNHN) . COLOMBIA: Cali : Fassi, S. Antonio, 2000 m, 4 specimens ( FMNH) . COSTA RICA: San José: Finca la Caja bei San Jose, Frühjahr 1930, H. Schmidt, Eing. Nr. 154, 2 specimens ( FMNH) . Heredia: Vara Blanca , 2000 m, 8.38 and II.36, 2 specimens ( FMNH) . Alajuela: Zarcero , VI.1943, 2 specimens ( FMNH) . Rabo de Mico : 1800m, 6.8.43, 1 specimen ( FMNH) . CUBA: Pto Esperanza : 4.I.1930, 1 specimen ( FMNH) . PANAMA: Volcan Chiriquí, VII.1930, 3 specimens ( FMNH) . URUGUAY: Montevideo: J. Tremolleras, 1 specimen ( MLPA) .