Philonthus politus ( Linnaeus, 1758 )

Chani-Posse, Mariana, 2010, Revision of the southern South American species of Philonthus Stephens (Coleoptera: Staphylinidae) 2595, Zootaxa 2595, pp. 1-70 : 44-45

Philonthus politus ( Linnaeus, 1758)

( Figs. 102–104, 145)

Staphylinus politus Linnaeus, 1758: 422 . For complete references see Herman (2001b).

Diagnosis. Philonthus politus may be identified by its coloration and general habitus, the distance separating medial interocular punctures on frons about twice as large as distance separating medial punctures from lateral punctures, and the three first abdominal terga with posterior basal line acutely extended medially. It differs from Philonthus rectangulus by the dorsal rows of the pronotum each with four punctures, and the aedeagus with paramere entire, not divided.

Redescription. Length of the body 9.0–13.0 mm. Coloration. Head, thorax, elytra and abdomen castaneous-piceous to black; elytra with pubescence testaceous, slightly iridescent; antennae, palpi and legs castaneous-piceous.

Head moderately to distinctly wider than long (HW/HL= 1.4–1.3) and at basal third as wide as distal third in both sexes, about as wide as pronotum (HW/PW= 1.0–0.97); 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 about twice as large as distance separating medial punctures from lateral punctures; infraorbital ridge present, extending not far beyond postgenal ridge. Eyes moderately longer than temples (EL/TL= 1.20) seen from above. Antennae with segment 1 shorter than segments 2 and 3 combined, segments 2 and 3 subequal in length, segment 4 elongate, 5 quadrate, segments 7–10 transverse. Maxillary palpus with segment 2 not swollen, more than twice as long as its maximum width; last segment fusiform, about twice longer than segment 3. Posterior arms of gular sutures either running close to each other until the base of head and not joined before neck or joined before neck. Submentum about 2.5 times as long as mentum. Labial palpus with last segment about twice as long as preceding segment. Neck more than 0.5 times as wide as head at widest point (NW/HW= 0.6).

Pronotum about as long as wide (PW/PL= 1.00–0.97), slightly narrowed anteriad to parallel-sided; dorsal surface of pronotum with two rows of punctures, each with four 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 (Fig. 2). Both 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 longer than last segment (S1/S5= 1.5–1.3). Abdominal terga distinctly punctuate at basal area, distance separating punctures smaller than diameters of punctures; terga 2 and 3 with elevated area between basal lines punctuate, posterior basal line acutely extended medially. Male sternum 7 with apical margin slightly notched. Tergum 8 in both sexes with posterior margin arcuate to subtruncate.

Male genitalia. Sternum 8 deeply emarginate medio-apically, with three long subapical macrosetae at each side. Tergum 10 slightly emarginate medio-apically, with four long subapical macrosetae and four short apical setae. Sternum 9 moderately emarginate apically, with one long subapical seta at each side ( Fig. 102). Aedeagus with a single tooth on face adjacent to paramere; apex of median lobe distinctly narrowed and elongate (in dorsal view) in its apical fourth; paramere entire, leaf-like, reaching two thirds of median lobe length, with many sensory peg setae at apex ( Figs. 103–104). Internal sac without sclerotized structures.

Female genitalia. Tergum 10 arcuate medio-apically, with two long subapical macrosetae and 8–10 short apical setae. Second gonocoxite with 2–5 strong setae along its outer margin, with stylus and two long long setae at its apex.

Geographical distribution. Philonthus politus is an Oriental species, which was introduced to various regions of the world, and it is now considered a cosmopolitan species ( Smetana 1995). Until the present work, P. politus was known in South America from Venezuela, Chile and Argentina ( Herman 2001b; Newton & Thayer 2005). Among the southern South American material that I have examined, only specimens from Chile of P. politus were found. They were collected in the biogeographical provinces of Santiago, Valdivia and Maule (Andean region) ( Fig. 145).

Bionomics. According to Smetana (1995), Philonthus politus is found in all kinds of decaying organic matter and in habitats associated with human settlements. According to collecting data, it may be found in Nothofagus forests and collected from carrion traps.

Type material. Linnaeus (1758: 422) described the species from specimens from Europa. I was not able to see the original material but there is little doubt that this species, as interpreted later by other authors ( Smetana 1995; Coiffait & Sáiz 1968; Schillhammer 2000) is the species that Linnaeus described.

Additional material: 34 specimens (10 ♂, 15 ♀, 9 unsexed)

CHILE: Cautín: P.N. Conguillio, 1.5km Laguna Captren, 23.XII.1996 – 5.II.1997, A. Newton & M. Thayer, 1365m, carrion trap (squid), Nothofagus obliqua & alpina with Chusquea understory, 1 ♀ ( FMNH). Curicó: Romeral, 18.IX.65, Philonthus politus Det. F. Saiz 1970 , 1 specimen (C. Sáiz). Santiago: XII.1978, L. E. Peña leg., ex series at Carnegie Museum, N. H. Field Mus. Nat. Hist., 2 ♂, 1 ♀ ( FMNH); 12.10.69, 1 ♀ ( MNHN). Talca: Area de Proteccion Vilches, near tree nursery, 18.XII.1996 – 8.II.1997, A. Newton & M. Thayer, 1180m, 35° 36.39' S, 71° 04.34'W, carrion trap (squid), FMHD 96-216, Nothofagus spp. & other forest, low shrubby, 1 ♂, 1 ♀ ( FMNH). Valdivia: June 20, 1976, Ernesto Krahmer, 8 specimens ( AMNH); 8.X.1976, L. E. Peña, Field Mus. Nat. Hist., 7 ♂, 10 ♀ ( FMNH); Puerto Fuy, 16.XII.1984 – 11.II.1985, S & J. Peck, 800m, FMHD #85-33, carrion trap, Field Mus. Nat. Hist., 1 ♀ ( FMNH).