Mecosarthron buphagus

Authors: Antonio Santos-Silva, Steven W. Lingafelter

Mecosarthron buphagus (Buquet, 1840) 
(Figs. 2, 5A, B)

Mecosarthron buphagus Buquet, 1840: 172; White, 1853: 10; Thomson, 1864: 296; 1878: 17; Lacordaire, 1868: 90; Lameere, 1903b: 318; Melzer, 1919: 38; Penteado-Dias, 1984: 226; Blackwelder, 1946: 552 (checklist); Monné & Giesbert, 1994: 5 (checklist); Monné, 1995: 7 (cat.); Monné & Hovore, 2005: 14 (checklist); 2006: 13 (checklist); Monné, 2006: 54 (cat.)

Stenodontes (Mecosarthron) buphagus; Lameere, 1903a: 136.

Male (Fig. 2A-C). Integument piceous to dark reddish-brown except for apical 3/4 of elytra which are lighter reddish-brown; elytra moderately shiny with inconspicuous, very short, fine, translucent pubescence.
Head integument with shagreened appearance, more coarsely developed between eyes and on antennal tubercles, more finely developed on vertex and occiput; very few defined punctures present; pilosity short, sparse, becoming denser in indistinct patches behind eyes; broad at base (10-12 mm). Labrum centrally moderately concave, arcuate at base; pilosity of moderate length and density, projecting forward. Eyes large, singularly lobed, with only very vague indication of indentation at side near antennal tubercle; from lateral view, eye extends nearly entire height of head from vertex to gula, somewhat broader ventral to tubercle than dorsally; from ventral view, eye occupies about 50% of length of head from anterior genal apex to posterior pronotal margin. Minimum distance between upper eye lobes barely less than length of antennomere III; distance between lower lobes just greater than length of antennomere III. Area around eye margin not sulcate; strongly depressed between eyes on vertex. Gula between ventral lobes of eyes strongly vermiculate, lacking pubescence. Gena strongly produced anteriorly into broad tooth below mandibular insertion. Mandibles ventrally projecting, from 0.7 to 0.8 times the length of the head; with strong, acute, broad apical tooth, smaller tooth at middle, and weak tooth at base; coarsely, confluently punctate on outer surface, except for teeth (anterodorsally); mostly smooth on underside (posteroventrally); pilosity short, sparse, limited to margins and base. Antennae reaching to at least apical fourth of elytra. Scape elongate (11-13 mm), slightly longer than antennomeres II-III-IV together (extending to anterior third of pronotum); with denticles or spinules on mesal-ventral margin, weakly asperate on dorsolateral margin.
Pronotum slightly broader posteriorly than anteriorly; strongly multispinose on lateral margins (12-15 well defined spines), with poorly defined spines at anterolateral and posterolateral corners; densely, uniformly reticulate-punctate; small, indistinct impunctate region anteromedially; lacking ridges or raised calli. Sparse, short, inconspicuous, translucent setae present, otherwise pronotum shiny and glabrous. Prosternum moderately vermiculate, without distinct punctures. Prosternal process wide, narrowed and elongated posterior to procoxae. Pubescence of prosternum short, sparse, but more conspicuous than on pronotum.
Elytra weakly shiny, mostly covered with very short, fine, translucent pubescence; lacking punctures; microrugulate and shagreened throughout. Elytra each with two vaguely indicated, minimally raised costae equally spaced from suture laterally, and a third vague depression between lateral-most costa and lateral margin.
First and middle legs asperate and covered in spinules, particularly on inner margins; metafemora and metatibiae smoother, with scattered asperites throughout and microspinules irregularly scattered along inner margin; protibiae each with two small, separate spurs apicomesally and a larger spine apicolaterally. Protibiae barely curved mesally from base to apex. Femora and tibiae of the same length for each leg. Forelegs longest (profemora/protibiae, 19-21 mm), middle legs shortest (mesofemora/mesotibiae, 16-17 mm), hind legs intermediate in length (metafemora/metatibiae, 18-20 mm).

Female (Fig. 2D-F): General appearance similar to that of male. Head distinctly smaller (8-9 mm wide at base); antennae reaching middle of the elytra; scape relatively short (7-9 mm; just surpassing the anterior pronotal margin). Pronotum uniformly reticulate, with vaguely defined middle longitudinal line or depression. Legs mostly smooth, not asperate, with scattered spinules on inner margins of tibiae and femora. Forelegs subequal in length to hind legs; slightly outwardly curved apically.

Dimensions in mm, males, n = 2: Total length (including mandibles), 73-75; length of prothorax, 11-12; width of prothorax between bases of posterolateral spines, 19-20; width of prothorax between bases of anterolateral spines, 17-19; body width at humeri, 20-22; elytral length, 47-50. Females, n = 2: Total length (including mandibles), 56-72; length of prothorax, 7-10; width of prothorax between bases of anterolateral spines, 13-15; width of prothorax between bases of posterolateral spines, 14-18; body width at humeri, 17-22; elytral length, 41-50.

Remarks on sexual dimorphism: Sexual dimorphism is not as apparent as in Xixuthrus species. Males have the pronotum less broadened posteriorly than anteriorly as compared to females, but sculpturing is very similar. Males have more strongly multispinose pronota laterally (12-15 spinules laterally) as compared to females (less than 10 poorly defined spinules laterally). Head of males slightly broader at pronotal insertion than in females. Mandibles only slightly smaller in females compared to males, but in both cases very similar to overall head length. The front and middle legs are strongly spinulose and asperate in males and very weakly so in females. The protibiae of males are straight to slightly curved mesally toward apex (inward curvature) while in females they are outwardly curved toward apex. The antennae of females reach to about the middle of the elytra, while in males, the antennae reach to at least the apical fourth of the elytra.

Geographical distribution: Mecosarthron buphagus occurs in eastern Brazil from Bahia to Paraná (Monné, 2006).
Type data: Holotype male, from Brazil (no other data), deposited at MNHN.

Material examined: All BRAZIL: Minas Gerais: male (USNM); Campo Bello, female, 18-I-1938, Tippmann Coll. (USNM); Lambari, female, 3-I-1927, Halik Coll. (USNM). Espírito Santo: Viana, male, I-1935, A. Maller, Tippmann Coll. (USNM).Mecosarthron buphagus (Buquet, 1840) 
(Figs. 2, 5A, B)

Location: Brazil