Brachystethus vicinus SIGNORET,1851:344; WALKER, 1868:455; STÅL, 1872:48; DISTANT, 1880:85; LETHIERRY & SEVERIN, 1893:187 (cat.); KIRKALDY, 1909:152 (cat.); FROESCHNER, 1981:69 (cat.); MAES, 1994:8 (cat.).

Type material. Lectotype and paralectotype, here designated, both labeled: a) Brazil, Coll. Signoret, b) vicinus det. Signoret (NHMW). Typelocality: Brazil.

Description. Dorsal surface castaneous to dark-castaneous, with a yellowish marginal stripe (fig. 13). Head castaneous to dark-castaneous, almost black, with wellmarked wrinkles. Punctures moderately distributed. Outer margins of jugae with yellow stripe, wider at base. Antennae dark-castaneous to black, except the first segment, yellowish at base. Fourth antennal segment cylindrical, lacking longitudinal sulcus. Second antennal segment one and a half longer than first and about 3/4 as long as third; third a little more than half as long as fourth, fifth the longest, a little longer than fourth. Pronotum castaneous to dark-castaneous; anterolateral margins with continuous yellow stripe. Medium-sized punctures concentrated before cicatrices and scarce after that, more frequent on anterior half of pronotum. Scutellum coarsely punctured, punctures more frequent on anterior half. Costal margins of corium with yellow stripe on anterior third, evanescent posterad. Yellowish callus near and entad apex of radial vein. Legs dark-castaneous, except coxae, basal 3/4 of trochanters, apex of femora and base of tibiae, yellowish. Ventral surface of thorax castaneous, with yellow stripe along lateral margins of propleura. Punctures fine, castaneous. Ostiolar rugae reaching 2/3 of distance between inner margin of ostiolum and lateral margin of metapleura. Metasternum, in profile, strongly elevated anteriorly. Connexivum with continuous yellow stripe along outer margin of segments, variable in width. Punctures fine, dense and homogeneously distributed on inner half of each segment. Venter castaneous; lateral margins with a continuous yellow stripe. Punctures fine and concolor, moderately distributed, less frequent in the middle. Spiracles yellowish.

Male genitalia. Pygophore trapezoidal, much wider apically. Lobes of dorsal rim inconspicuous. Genital cup processeslittle visibledorsally (figs. 23, 33). Parameres long, withacute apex, turnedanterad (fig. 52). Ventral rim V-like, deeplyexcavatemedially (fig. 43).

Measurements (n=4). Headlength 2.20 (2.00-2.34) ± 0.15, width 3.53 (3.36-3.67) ± 0.14; interoculardistance 1.85 (1.76-1.95) ± 0.09; anteocularlength 0.79 (0.74-0.86) ± 0.05; lengthof antennalsegments: I - 1.09 (0.96-1.25) ± 0.14; II - 1.68 (1.56-1.83) ± 0.11; III - 2.21 (1.84-2.42) ± 0.26; IV - 3.83 (3.24-4.29) ± 0.54; V - 4.78 (4.24-5.62) ± 0.73; pronotallength 5.30 (4.84-5.68) ± 0.37, width 12.11 (11.19-12.69) ± 0.67; scutellarlength 7.76 (7.28-8.24) ± 0.44, width 7.40 (7.04-7.76) ± 0.34; coriumlength 10.19; abdominalwidth 13.34 (12.27- 14.20) ± 0.93; totallength 18.83 (16.87-20.21) ± 1.59.

Female genitalia. Posterior borders of gonocoxites 8 projected in acute angle, over the limit between laterotergites 8 and laterotergites 9; slightly convex on area adjacent to laterotergites 9 andgonocoxites 9 (fig. 64). Sutural borders of gonocoxites 8 parallel and contiguous. Gonocoxites 9 less than twice and a half wider across apices of arms than long medially; anterior border sinuate, little excavate medially. Arms of gonocoxites 9 about 1/6 as long as plate width. Thickening of vaginal intima digitiform. Ductus receptaculi more than one and a half longer before than after vesicular area, equally thickened in both regions. Capsula seminalis globose. Annular crests convergent (fig. 72).

Measurements (n=6). Headlength 2.38 (2.16-2.50) ± 0.13, width 3.66 (3.36-3.90) ± 0.22; interoculardistance 1.95 (1.84-2.07) ± 0.12; anteocularlength 0.80 (0.74-0.88) ± 0.05; lengthof antennalsegments: I - 1.11 (1.04-1.21) ± 0.08; II - 1.72 (1.60-1.91) ± 0.13; III - 2.20 (1.84-2.42) ± 0.23; IV - 3.84 (3.40-4.10) ± 0.38; V - lacking; pronotallength 5.83 (5.18-6.35) ± 0.52, width 13.29 (12.02-14.53) ± 0.99; scutellarlength 8.72 (8.35-9.12) ± 0.33, width 8.24 (7.52-8.88) ± 0.50; coriumlength 12.08 (11.86-12.36) ±0.26; abdominalwidth 15.13 (14.03- 16.03) ± 0.88; totallength 20.61 (19.04-22.38) ± 1.53.

Material examined. GUYANA, Essequibo: Kaieteur Fall (high forest),, 3.IX.1937, Richards & Smart (BMNH 1937-776). BRAZIL, (NHMW); Pará: Mocajuba (Mangabeira),, XI.1952, Orlando Rego (MNRJ); Bahia:, 2, 1859, Dr. Felder (NHMW); Espírito Santo: Conceição da Barra,, 27.V.1969, C.T. & C. Elias (DZUP); São Paulo: Araras (Us. Santa Lúcia),, 12.VII.1983, P.R. Cancian (UFRG); Campinas,, XI.1986, L.O.T.M. (UFRG).

Distribution. Guyana (Essequibo), Brazil (Pará, Bahia, Espírito Santo, São Paulo).

Comments. Brachystethus vicinus is the sister group of B. improvisus, distinguishing from this species, in the males, by the shape of parameres, with acute apex, by the inconspicuous lobes of dorsal rim of pygophore and by the genital cup processes little visible dorsally. In the females, the posterior borders of gonocoxites 8, projected in acute angle over the limit between laterotergites 8 and laterotergites 9, also separate B. vicinus from B. improvisus.