Mecosarthron gounellei ( Lameere, 1903a )

Santos-Silva, Antonio & Lingafelter, Steven W., 2012, Morphological Analysis Of Mecosarthron Buquet And Xixuthrus Thomson And Reevaluation Of Generic Assignment Of Xixuthrus Domingoensis Fisher (Coleoptera, Cerambycidae, Prioninae), Papéis Avulsos de Zoologia 52 (27), pp. 315-332 : 326-328

Mecosarthron gounellei ( Lameere, 1903a)

( Figs. 3 , 6 )

Stenodontes (Mecosarthron) gounellei Lameere, 1903a: 135 .

Mecosarthron gounellei ; Lameere, 1903b: 318; 1913: 11 (cat.); 1919: 29, pl. 2, fig. 7; Melzer, 1919: 40.

Mecosarthron gounellei : 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.).

Redescription: Male ( Fig. 3 A-C). Integument dark brown, shining; mandibles blackish; tarsi and distal antennomeres slightly lighter.

Head coarsely and confluently punctate between the eyes, almost vermiculate; area between the posterior edge of eyes and occiput moderately, finely granulate; pilosity short and sparse between the eyes, distinctly more abundant between eyes and occiput. Labrum centrally, strongly concave, coplanar with clypeus at base; pilosity long, abundant, projected forward. Area behind eyes granulated between apex of upper ocular lobes and approximately the basal third of lower eye lobes (granules coarser and sparser than dorsal area of head behind upper lobes and slightly finer and closer behind lower lobes); area behind apical two-thirds of lower eye lobes transversely sulcate. Gular area strongly vermiculate; pilosity of short setae intermixed with long setae (more distinct in lateral view). Eyes wide; distance between upper lobes equal to or slightly wider than the length of antennomere III; distance between lower lobes slightly greater than between upper lobes. Mandibles from 0.5 to 0.6 X the length of the head; coarsely, confluently punctate, deeper on outer surface; pilosity short, moderately sparse. Antennae surpassing middle of elytra. Scape about as long as antennomeres III-IV together; dorsally flat, coarsely, confluently punctate, mainly on basal half; ventrally vermiculate, mainly on basal two-thirds, without denticles; distinctly surpassing posterior edge of eyes.

Gibbosities of pronotum less punctate on inner face than outer face and areas around them; pilosity short, moderately sparse, more abundant on small area close to posterior angles. Prosternal process wide and rounded at apex. Elytra coarsely, abundantly punctate; elytral costae present, but not well defined; pilosity short, sparse. Profemur scabrous on lateral surface (visible on dorsal view), vermiculate or punctate laterad; ventral surface with small spines on apical half (only near apex in small specimens); rugose-punctate on dorsal surface; meso- and especially metafemora less strongly sculptured than profemora. Tibiae with similar length, slightly, but distinctly enlarged from base to apex; protibiae with smaller spines on ventral surface (almost absent in smaller specimens).

Female ( Fig. 3 D-E): Examined only from a photograph. General appearance similar to that of male.

PAPÉIS AVULSOS DE ZOOLOGIA, 52(27), 2012 327

Head distinctly smaller; antennae reaching apex of basal third of elytra; scape reaching approximately to the apex of posterior edge of eyes.

Dimensions in mm, n = 2:Total length (including mandibles), 32-49; length of prothorax, 5-8; width of prothorax between bases of anterolateral spines, 9-13; width of prothorax between bases of posterolateral spines, 9-14; body width at humeri, 10-15; elytral length, 21-33.

Geographical distribution: Mecosarthron gounellei is known only from northeastern Brazil (Bahia).

Type data: Holotype male ( Fig. 6 ), from Brazil: Santo Antonio da Barra , Bahia, collected by Gounelle, on 11.XII.1888, deposited at MNHN.

Material examined: BRAZIL, Bahia: female, same data as the holotype; Encruzilhada (Rio-Bahia road, km 965; “ Motel da Divisa ”; 960 m), male, XI.1972, Seabra & Roppa col. ( MNRJ); male, same data but XI.1974, Seabra & Roppa col. ( MNRJ) .

Remarks: Mecosarthron gounellei differs notably from the other species of the genus by having the prosternal process distinctly enlarged and rounded at the apex ( Fig. 3B ) and the elytra distinctly punctate and sparsely pubescent ( Figs. 3A, C, D ). In M. buphagus ( Figs. 2B, E ) and M. tritomegas ( Fig. 7B ) the prosternal process is narrowed towards the apex and the elytra are distinctly pubescent and not notably punctate (see Figs. 2A, D and 7A , respectively).

According to Lameere (1903a) the specimen was “capture à San Antonio da Barra, province de Bahia, au Brésil, le 11 décembre 1888 ”. Santo Antonio da Barra is now Condeúba, and the vegetation in the area is transitional between forest, cerrado (characterized by extensive savanna formations crossed by gallery forests and stream valleys, that includes various types of vegetation), and caatinga (composed of stunted trees and thorny bushes, found in areas relatively xeric areas in Brazil). However the locality is situated near the area with vegetation characteristic of a “seasonal forest”, with general appearance of a forest with trees reaching 25 to 30 meters in height, covered with lianas and epiphytes. This Brazilian region displays notable endemism of Cerambycidae (e.g., Antodice lenticula Martins & Galileo ; Adetus minimus Breuning ; Dorcasta quadrispinosa Breuning ; Corimbion balteum Martins ; and Minibidion confine Martins ). Generally specimens from this region are not common in the large collections of insects in Brazil (with the exception of MNRJ, where there is a good number of specimens collected by C.A. Campos Seabra in Pedra Azul (Minas Gerais), a place somewhat near Condeúba, but placed in the area of “Seasonal Forest”).

Lameere (1903b) recognized that the species is very distinct when compared with M. buphagus , and wrote: “C’est, parmi les Mécosarthrines, une forme très primitive qui ne peut se rattacher qu’à un type tel que Omotagus Lacordairei ”. Given that Lameere had a very broad generic approach (for example, with his concept of Callipogon Audinet-Serville, 1832 , that included as subgenera Navosoma Blanchard, 1846 and Spiloprionus Aurivillius, 1897 ), some could conclude that this unusual species merits a separate genus.

Lameere (1903b) wrote about the antennae: “Ce Mecosarthron [ M. buphagus ], supérieur au précédent, nous offre la répétition de ce phénomène d’allongement du 1 er article des antennes qui s’est produit également dans l’évoultion des Xixuthrus , mais, chez ces dernieers, le phénomème [sic] s’accompagne d’un allongement du 3 e article des antennes”. However, although in Xixuthrus the scape can vary in length, the variation in form is not pronounced, while the form of scape of M. buphagus is very different from that of M. gounellei .

Figures

FIGURE 2: Mecosarthron buphagus Buquet. A. dorsal habitus, male; B. ventral habitus, male; C. lateral habitus, male; D. dorsal habitus, female; E. ventral habitus, female; F. lateral habitus, female.

FIGURE 3: Mecosarthron gounellei (Lameere). A. dorsal habitus, male; B. ventral habitus, male; C. lateral habitus, male; D. dorsal habitus, female; E. lateral habitus, female.

FIGURE 6: Mecosarthron gounellei (Lameere), holotype (male). A. dorsal habitus; B. ventral habitus; C. holotype labels.

FIGURE 7: Mecosarthron tritomegas Lameere, holotype (male). A. dorsal habitus; B. ventral habitus; C. holotype labels.