Aleochara atra ( Solier, 1849 )

Moussallem, M., Ribeiro-Costa, C. S. & Caron, E., 2014, Review of Solier's Mecorhopalus species (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 3852 (5), pp. 540-552 : 541-545

Aleochara atra ( Solier, 1849)

Mecorhopalus ater Solier, 1849:348 (Description, type locality: “Santiago y Valdivia). Kraatz 1859:11 (Revision, as valid name). Tottenham 1939:228 (Cited as type of Mecorhopalus , invalid as discussed above).

Aleochara atra: Fairmaire & Germain, 1861:414 (Revision, the first time cited as Aleochara ). Fauvel, 1864:121 (Revision, as valid name). Fauvel 1866:285 (Revision, cited as synonym of A. lata ). Bernhauer & Scheerpeltz, 1926:776 (Catalogue, as valid name). Caron et al., 2008:831 (Checklist, as valid name).

Aleochara humilis Fauvel, 1866:286 (Description, type locality: Santiago). Pace, 1990:174 (Cited as subjective synonym of A. atra ). Caron et al., 2008:831 (Checklist, as junior synonym of A. atra ).

Aleochara gravenhorsti Blackwelder, 1944:167 (Objective synonym, incorrect preoccupied name for A. atra ). Caron et al., 2008:831 (Checklist, as junior synonym of A. atra ).

Aleochara paleoatra Pace, 2000:404 (Objective synonym, incorrect preoccupied name for A. atra ). Caron et al., 2008:831 (Checklist, as junior synonym of A. atra ).

Note. For a complete discussion about synonyms and the valid name of this species see Caron et al. (2008).

Type material. Mecorhopalus ater : type sex not determined, one specimen, syntype, deposited in FMNH: (1) “ Chile. Coll. So-/ lier & fairm./ m(?)us. Germ.” [White label handwritten with India ink]. The letter “m” in “mus. Germ” is stained by the ink, we believe it stands for museum Germain]. (2) “ atra Solier / det. Bernhauer” [White label, “det Bernhauer” typed in black ink, other information handwritten in India ink] Note 1. According to the ICZN (1999) article 72.4.1.1, “For a nominal species or subspecies established before 2000, any evidence, published or unpublished, may be taken into account to determine what specimens constitute the type series.” We assume this specimen is the type of Mecorhopalus ater because this specimen is part of Solier’s collection—label (1). Note 2. Solier did not mention the number of specimens in the type series, as a conservative approach (and following article 72.1.1 of the ICZN 1999) we suggest that this specimen should be considered as a syntype.

Aleochara humilis : male, one specimen, syntype, deposited in IRSBN: (1) “Santigo” [White label, handwritten with India ink]. (2) “Coll. et det. A. Fauvel/ Aleochara / humilis Fvl. / R.I.Sc.N.B. 17.479” [White label, “Coll. et det. A. Fauvel” and “R.I.Sc.N.B 17.479” printed in black ink, other information handwritten with India ink]. (3) “ Aleochara / atra (Sol.) / det. R. Pace 1985” [White label, “det. R. Pace 19” printed in grey ink, other information handwritten with India ink]. Note 1. According to ICZN (1999) article 72.4.1.1, we assume this specimen is the type of Aleochara humilis because it is part of Fauvel’s collection—label (2) and coincides with the type locality—label (1). Note 2. Fauvel did not mention the number of specimens in the type series, as a conservative approach (and following article 72.1.1 of the ICZN 1999) we suggest that this specimen should be considered as a syntype. Note 3. The specimen arrived with a label [White, handwritten with India ink] (not included on the pin) written: “ atra sol. type ”.

Additional material. FMNH: Twenty-three specimens. One specimen: (1) “ Aleochara / atra / Südchile” [White label on graph paper, handwritten with India ink]. (2) “Chicago NHMus/ M.Bernhauer/ Collection” [White label printed in black ink]. Four specimens (on the same insect pin): (1) “ Chile ” [White label, handwritten with India ink]. (2) “ lata ?” [White label handwritten with India ink]. (3) “ atra Sol. / Chile. Luse. / det. Bernhau” [White label “det. Bernhau” typed in black ink, other information handwritten. We believe “er” from Bernhauer has been cut off the label]. (4) “Chicago NHMus/ M.Bernhauer/ Collection” [White label, printed in black ink]. One specimen: (1) “ Chile ” [White label, handwritten]. (2) “Chicago Nat. Hist. Mus./ (ex M. Cameron Colln./ by exchange with/ Brit. Mus. Nat. Hist.)” [White label, printed in black ink]. (3) “ Aleochara / atra Solsky ” [White label, handwritten with India ink. Probably a mistake: Solsky instead of Solier]. Ten specimens: (1) “ CHILE: Quillota Prov.,/ Olmue, La Campana/ N. P., 800 – 900 m, 2.XII.84 – 21.II.85 ” [White label, printed in black ink]. (2) “ FMHD #85-887/ hygrophilous for.,/ S.&J. Peck, P#85-2,/ carrion trp./ FIELD MUSEUM NAT HIST.” [White label printed in black ink]. (3) “ Aleochara / atra (Sol.) / det. R. Pace 1992” [White label, “det. R Pace 19” printed in black ink, other information handwritten with India ink.]. Three specimens: with identical labels, and with addition of a fourth label: (4) “female” [White label printed in black ink]. Two specimens: with identical labels with exception of label (3), which in the second line is written “ atra (S.)” instead of “ atra (Sol.) ” One specimen: (1) “ CHILE: Malleco Prov.,/ 11 km W Angol,/ 9.XII.1984 -/ 16.II.1985 ”. [White label, printed in black ink] (2) “ FMHD #85-901, boggy/ mixed forest remnant/ S. Peck, P#85-15,/ carriion trap/ FIELD MUSEUM NAT HIST ” [White label printed in black ink. Carrion is written with two letters “i” instead of one]. (3) “ Aleochara / atra (Sol.) / det. R. Pace 1992” [White label, “det. R Pace 19” printed in black ink, other information handwritten with India ink]. (4) “m#” [White label printed in black ink]. One specimen: (1) “ CHILE: Nuble Prov., 72/ km SE Chillan, Trancas/ nr Termas,/ 6.XII.1984 – 19.II.1985 ”. [White label printed in black ink]. (2) “ FMHD #85-895, beecn/ forest, S. Peck,/ P#85-10, carrion trap/ FIELD MUSEUM NAT HIST ” [White label printed in black ink. We believe “beech forest” was written in the first line, but due to the cutting of the label the “h” looks like an “n”].(3) “ Aleochara / atra (Sol.) / det. R. Pace 1993” [White label, “det. R Pace 19” printed in black ink, other information handwritten with India ink. The handwriting of the last digit of the year is indistinct looking like a “3”]. IRSBN: five specimens. One specimen: (1) “Santiago” [White label, handwritten with India ink]. (2) “Coll. R. I. Sc. N. B.” [White label, printed in black ink]. One specimen: “I de (?) Juan/ Fernandez/ Chili ” [White label, handwritten with India ink. It is difficult to read due to the handwriting. We assume it stands for Juan Fernandez Island, in Chile]. (2) “Coll. R. I. Sc. N. B.” [White label, printed in black ink]. One specimen: “ Chili ” [White label, handwritten with India ink]. (2) “Coll. R. I. Sc. N. B.” [White label, printed in black ink]. One specimen: (1) “Prov. de Neuquen/ Rep. Argent.” [White label, handwritten with India ink]. (2) “Coll. R. I. Sc. N. B.” [White label, printed in black ink]. One specimen: (1) “Coll. R. I. Sc. N. B.” [White label, printed in black ink].

Diagnosis. This species is easily distinguished from other species of the lustrica group ( A. lustrica Say, 1832 , A. curtula ( Goeze, 1777) and A. centralis Sharp, 1883 ), by the body entirely black, elytra without paler spot or paler colors (present in those species) and by the shape of spermatheca; A. lustrica has the capsule elongated, A. curtula has the chamber about as thick as the capsule, A. centralis spermatheca is L-shaped contrasting with A. atra which is C-shaped and has the capsule globular and wider than the chamber. Differs from A. lata Gravenhorst, 1802 by the shape of genitalia of which the median lobe is narrower and less globular than A. atra and the apex of paramere is thicker than that of A. atra , the spermatheca has the chamber thicker than the capsule, contrasting with A. atra , which is narrower. A. pseudochrysorrhoa Caron et al., 2008 can easily be distinguished from A. atra by the apex of abdomen (half of segment VII and VIII—is lighter, yellowish to rusty brown), parameres with a slender condylite and spermatheca L-shaped.

Redescription. BL: 4.7–5.4 mm. EW: 1.5–1.6 mm

Body compact and robust ( Fig 1 a–c), pronotum about the same width as elytra or slightly wider ( Fig. 1 d); body uniformly dark to piceous black with elytra reddish; tarsi, maxillary and labial palpi light brown; surface glossy and pubescent with pale setae, setigerous pores impressed. Head triangular with the base rounded, antennae with antennomere II smaller than the first, antennomere IV slightly transverse, antennomeres V-X gradually widening, antennomere XI twice longer than the precedent one and subtriangular in shape; maxilla with palpus 4-articulated with a minute pseudopalpomere at the apex of the last palpomere. Pronotum transverse with posterior margin arcuate, pubescent with straight setae directed posterad medially and obliquely in the lateral area. Mesoventrite without medial carina, reaching near the posterior margin of mesocoxae, apex broadly rounded to subtruncate. Elytra as long as the pronotum [EL/PL = 1.2], length about equal to width [EL/EW = 1.2], pubescent with straight setae directed posterad, hind wings well developed. Abdomen gradually narrowed posteriorly, glossy, pubescence sparse and very fine directed posterad, paratergitum distinctly marked until the fifth visible tergum (tergum VII).

Male: Tergite VIII pubescent with many small setae positioned in the anterior area, some macrosetae in the postero-medial area (fig. 2a); posterior margin truncate to slightly emarginate with about 15–16 small teeth in the border which are strongly marked in the median area (fig. 2b); lateral margin sub-parallel, forming a quadrangular shape. Sternite VIII pubescent with small and numerous setae; posterior margin truncate to slightly emarginate, about half of the length of anterior margin (fig. 2c); lateral margins somewhat convex, forming a sub-hexagonal shape. Tergite IX divided and not contiguous, each side with asymmetrical ventral struts, lateral margin pubescent (fig. 2d). Tergite X with the margin slightly emarginate (fig.2d); anterior and posterior margins about the same length; postero-medial area pubescent with small setae, getting larger at the posterior margin of the sclerite. Sterntite IX translucent; apical area with pubescence in a triangular format, no longer than of the length, restricted to this area (fig. 2e). Aedeagus: Medial lobe with expanded bulbus, short tubus and acute apex, sclerites of internal sac forming complex arrangement (fig. 2f–g). Parameres well developed with four apparent setae in the apical lobe, two smaller in the apex and two longer, about 5–6 times the size of those in at the apex; velar sac well developed, about two thirds of the length of the parameres; velar phragma oblique (fig. 2h).

Female: Tergite VIII similar to that of male but without the serration and with a slight medial emargination on the posterior margin (fig. 2i –j). Sternite VIII with the posterior margin shorter than that of a male, about one third of the anterior angle’s length, the lateral angles are more pronounced, forming a truncated sub-triangular shape, pubescence similar that of to a male´s (fig. 2k). Tergite IX without ventral struts (fig. 2l). Tergite X narrower than that of male (fig. 2l). Spermatheca C-shaped; capsule curved; chamber curved, narrower than the capsule, in apical third slightly constricted; duct about half the size of the capsule (fig. 2m).

Subgeneric assignment Aleochara sensu strictu Gravenhorst 1802. Confirmed by: dorsal surface of body without microsculpture, pronotum evenly pubescent; mesoventrite not carinate; maxillary palpus long. For complete description of the subgenera see Klimaszewski (1984:70). Note: As Aleochara s. str. is the subgenus containing the type species of the genus Aleochara (nominotypical subgenus), we attribute the subgenus description to Gravenhorst, 1802, in accordance with the article 44.1. of ICZN (1999), and not to Mulsant & Rey, 1874 cited in earlier works ( Smetana 2004:353).

Remarks. We agree with the subjective synonym proposed by Pace (1990), and we consider A. humilis as a junior subjective synonym of A. atra .

Remarks 2. A. atra belongs to the lustrica species group (sensu Klimaszewski 1984:72), by having: antennal antenomere IV transverse, antonnomeres V-X twice as wide as long, pronotum densely pubescent, body large, aedeagus and spermatheca of a similar shape. Contrasting with gracilicornis species group (sensu Klimaszewski 1984:80), which have antennal articles IV and V-X, as long as wide or longer, narrower than in lustrica group; median lobe of aedeagus with smaller bulbus and spermatheca divided into three distinct parts.

Distribution. Material examined: Chile (Juan Fernandez Island, Malleco, Nuble, Quillota, Santiago and Valdivia); Argentina (Neuquen).

Biological notes. On additional labels: found in association with carrion; found in a mixed forest remnant.

Figures

FIGURE 1. Aleochara atra: a) Dorsal view; b) Ventral view; c) Lateral view; d) Pronotum and elytra.