Philonthus bruchianus, Chani-Posse, 2010

Chani-Posse, Mariana, 2010, Revision of the southern South American species of Philonthus Stephens (Coleoptera: Staphylinidae) 2595, Zootaxa 2595, pp. 1-70 : 20-21

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Philonthus bruchianus

sp. nov

Philonthus bruchianus sp. nov

( Figs. 37–41, 145)

Diagnosis. Philonthus bruchianus may be identified by the head wider than long, the antennal segments 4–10 elongate and the pronotum slightly narrowed anteriad to parallel-sided. It differs from other southern South American species of Philonthus by the eyes moderately shorter than temples, and the submentum about twice as long as mentum.

Description. Length of the body 7.8 mm. Coloration. Head castaneous- piceous; thorax castaneousbrunneous; elytra castaneous-piceous; abdominal segments castaneous-piceous becoming at apical margins; first three antennal segments castaneous-brunneous, other segments castaneous-piceous, palpi and legs castaneous-brunneous.

Head moderately wider than long (HW/HL= 1.2) and at basal third as wide as distal third in both sexes, about as wide as pronotum (HW/PW= 1.0); 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 twice as large as distance separating medial punctures from lateral punctures; infraorbital ridge present, extending not far beyond postgenal ridge. Eyes moderately shorter than temples (EL/TL= 0.83) seen from above. Antennae with segment 1 slightly shorter than segments 2 and 3 combined, segment 2 shorter than segment 3, segments 4–10 elongate. Maxillary palpus with segment 2 not swollen, more than twice as long as its maximum width; last segment fusiform, about 1.5 times longer than segment 3. Submentum about twice as long as mentum. Labial palpus with last segment 1.4–1.8 times as long as preceding segment. Neck more than 0.5 times as wide as head at widest point (NW/HW= 0.6).

Pronotum slightly longer than wide (PW/PL= 0.9), 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), distinctly longer than elytra along suture (EtL/Etl= 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 as long as last segment (S1/S5= 1.0). 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 straight. Tergum 8 with posterior margin slightly prolonged apically in both sexes.

Male genitalia. Sternum 8 deeply emarginate medio-apically. Tergum 10 subtruncate apically ( Fig. 38), with two long subapical macrosetae and six apical setae. Sternum 9 moderately emarginate apically with basal portion asymmetrical, two long subapical macrosetae and two apical setae at each side ( Fig. 37). Aedeagus with median lobe gradually narrowed from apical third; apex of median lobe subacute (in dorsal view) and simple in its apical fourth (in lateral view); paramere elongate and entire, spoon-like, reaching two thirds of median lobe length, with two lateral rows of sensory peg setae joined at apex ( Figs. 39–41). Internal sac with distinctly sclerotized structures.

Female genitalia. Tergum 10 similar to that of P. discoideus (see Fig. 58), with two long subapical macrosetae and three short apical setae at each side of the concave emargination. Second gonocoxite with one strong seta medio-basally, and stylus with two long apical seta.

Note. The species was recognized and labeled by Bernhauer, but never described.

Geographical distribution. Philonthus bruchianus is only known from one locality in northern Argentina (Tucumán) ( Fig. 145).

Bionomics. Unknown.

Type material. Holotype: ♂, “ Tucumán / Siambon/ VII.933 Bosq” “ 3 “ “ bruchianus Brnh. Typ. ” (white) “Chicago NHMus. / M. Bernhauer Collection ” “Bernhauer MS Name/ Current genus: Philonthus / teste A. Newton 1994” “ Holotype Philonthus bruchianus / Chani-Posse de Maus 2008 ” ( FMNH) . Paratype: ♀, “ Tucumán / Siambon/ VII.933 Bosq” “ 3 “ “ bruchianus Brnh. Typ. ” (white) “Chicago NHMus. / M. Bernhauer Collection ” “ Paratype Philonthus bruchianus / Chani-Posse de Maus 2008 ” ( FMNH) . Holotype originally pinned together with the paratype.

Etymology. The specific name is assumed to have been dedicated to Carlos Bruch by Bernhauer.


Field Museum of Natural History