Philonthus quadraticeps Boheman, 1858

Maus, Mariana Chani-Posse De, 2009, Revision of some types of Philonthus Stephens and Gabrius Stephens from southern South America (Coleoptera: Staphylinidae), with nomenclatural notes, Zootaxa 2034, pp. 31-42 : 35-37

Philonthus quadraticeps Boheman, 1858

( Figs. 5, 6 in this paper; Figs. 16–21 in Chani-Posse 2004)

Philonthus quadraticeps Boheman,1858: 28 ; Lynch-Arribálzaga, 1884: 150 (characters); Bernhauer & Schubert, 1914: 352 (catalog); Bruch, 1915: 445 (catalog); Blackwelder, 1944: 134 (list); Frank, 1982; 43 (list); Herman, 2001: 2928 (catalog); Chani-Posse, 2004: 224–227 (characters), 231 (list).

Philonthus tenebrosus Boheman, 1858: 28 ; Lynch-Arribálzaga, 1884: 149 (characters, Argentina); Bernhauer & Schubert, 1914: 357 (catalog); Bruch, 1915: 445 (catalog); Scheerpeltz, 1933: 1363 (catalog); Blackwelder, 1944: 135 (list); Herman, 2001: 2977 (catalog); Chani-Posse, 2004: 231 (list), syn. nov.

Type material. Lectotype of Philonthus quadraticeps (here designated; Figs. 5 a–b), 3, “ Type ”, “Buen Ayr”, “Kinb”, “ Typus ”, “ quadraticeps Bhn. ”, “5374 E91”, “Naturhistoriska Riksmuseet Stockholm / Loan no 834 / 06”, “ Lectotype Philonthus quadraticeps Boheman, 1858 / Des. Chani-Posse de Maus 2008” ( NHRS).

Lectotype of Philonthus tenebrosus ( NHRS) (here designated; Figs. 6 a–b), 3, “ Type ”, “Buen Ayr”, “Kinb”, “ Typus ”, “ tenebrosus Bhn. ”, “5373 E91”, “Naturhistoriska Riksmuseet Stockholm / Loan no 832/ 06”, “ Lectotype Philonthus tenebrosus Boheman, 1858 / Des. Chani-Posse de Maus 2008” ( NHRS). Paralectotype: 3, “Buen Ayr”, “Kinb”, “ tenebrosus Bhn. ”, “5375 E91”, “Naturhistoriska Riksmuseet Stockholm / Loan no 833/06”, “ Paralectotype Philonthus tenebrosus Boheman, 1858 / Des. Chani-Posse de Maus 2008” ( NHRS).

Diagnosis. Philonthus quadraticeps may be identified by the following characters: head and pronotum distinctly quadrate, antennal segments 4 and 5 quadrate, eyes shorter than temples seen from above, postmandibular ridge absent, dorsal rows on pronotum each with four punctures, and transverse distance between punctures of elytra larger than diameters of punctures. For further details and illustrations see Chani- Posse (2004).

Notes. I designate the lectotype of P. quadraticeps rather than assume that the examined type specimen is the holotype since in the original description Boheman (1858) gave no information about the number of specimens examined. Therefore, it is possible that this name was based on more than one specimen ( ICZN 1999, Recommendation 73F). The lectotype agrees with the description by Boheman (1858).

In the original description of P. tenebrosus ( Boheman 1858) there is no indication about how many specimens were included in the type series. Both specimens listed in the type material agree with the description by Boheman (1858). The specimen in a better condition is designated as the lectotype, the remaining specimen is a paralectotype.

Comments. My examination of the types of P. quadraticeps and P. tenebrosus ( Figs. 5 a–b, 6 a–b) revealed that both are identical in all external characters and identical in characters of the male genitalia. Difference between the two nominal species as described by Boheman (1858: 28) results mostly from slight variation in coloration of the antennae, mouthparts and abdomen. Since the lectotypes of both nominal species are conspecific and these two names were simultaneously established by Boheman (1858), they are considered to be subjective synonyms. Under application of the article 24.2.2 of the Code ( ICZN 1999), I give precedence to the name P. quadraticeps as valid name for the species and senior subjective synonym of P. tenebrosus .