Brachystethus schuhi, Jocélia Grazia, 2003

Barcellos, Aline & Grazia, Jocélia, 2003, Revision Of Brachystethus (Heteroptera, Pentatomidae, Edessinae), Iheringia, Série Zoologia 93 (4), pp. 413-446 : 428

Brachystethus schuhi sp. nov.

( Figs. 7 , 17, 27 , 37 , 47 )

Etymology. Named in honor to Dr. Randall T. Schuh, for his great contribution to the knowledge of Heteroptera .

Typematerial. Holotype, Guyana, nolocality, nodate, Babcock ( AMNH). Type locality: Guyana.

Description. Dorsal surface dark- to reddish-castaneous (reddish on apical 3/4 of corium) ( fig. 7). Headentirely dark-castaneous, almost black; wrinkles conspicuous. Punctures densely distributed. Antennae black. Second antennal segment more than one and a half longer than first and as long as third; fourth and fifth lacking on the holotype. Pronotum dark-castaneous. Punctures coarse, moderately distributed, more concentrated behind cicatrices; finer punctures, densely distributed, before cicatrices. Scutellum dark-castaneous; coarse punctures on basal 2/3, more concentrated along lateral margins. Corium reddish, excepton basal fourth, dark-castaneous, almost black; a yellowish callus near and entad apex of radial vein. Ventral surface of thorax darkcastaneous, almost black; finepunctures regularly distributedon propleura, mesoepisternum and metaepimerum. Ostiolar rugae reaching about half the distance between inner margin of ostiolum and lateral margin of metapleura. Metasternal carina, in profile, strongly elevated anteriorly. Legs dark-castaneous, almost black, yellowish-castaneous at apex of femora and baseof tibiae. Connexivalsegments dark-castaneous, withfinepunctures regularly distributed. Venter uniformly dark-castaneous, almost black. Punctures fine, distributed more densely among spiracles, and a narrow, impuctatedmedial stripe. Spiracles black.

Male genitalia. Pygophore subquadrangular, slightlywider apically. Lobes of dorsal rim little projected posterad, rounded at apex. Genital cup processes moderately visible dorsally ( figs. 17, 27). Paramereswith wide apex, laterally directed ( fig. 47). Ventral rim openly V-like ( fig. 37).

Measurements (n=1). Headlength 1.96, width 3.08; interoculardistance 1.52; anteocularlength 0.60; lengthof antennalsegments: I - 0.84; II - 1.36; III - 1.36; IV and V - lacking; pronotallength 4.34, width 10.19; scutellarlength 6.68, width 6.51; corium length 9.85; abdominalwidth 11.02; totallength 15.70.

Distribution. Guyana.

Comments. Brachystethus schuhi shares with its sister species B. cribrus the yellowish callus on corium, but can be distinguished by the following characters: venter uniformly castaneous, dark-castaneous coxae and genital cup processes moderately visible dorsally. Brachystethus schuhi is also closely related to B. signoreti and B. rubromaculatus ( BARCELLOS & GRAZIA, 2003), being distinguished from the the former by the callus on corium and male genitalia, and from the latter by the yellowish apex of femora and base of tibiae.

Figures

Figs. 2-13. 2, 3, Brachystethus rubromaculatus Dallas, 1851; 4, 5, B. signoreti Stål; 1872; 6, B. cribrus (Fabricius, 1781); 7, B. schuhi sp. nov.; 8, B. tricolor Bolívar, 1879; 9, B. vexillum Breddin, 1903; 10, B. geniculatus (Fabricius, 1787); 11, B. coxalis Breddin, 1904; 12, B. improvisus Breddin, 1905; 13, B. vicinus Signoret, 1851. Magnification 1.63X.

Figs. 24-29. Pygophore, caudal (tenth segment omitted): 24, Brachystethus rubromaculatus; 25, B. signoreti; 26, B. cribrus; 27, B. schuhi; 28, B. tricolor; 29, B. vexillum (dor, dorsal rim; gcp, genital cup process; pa, paramere; vr, ventral rim). Scale, 1 mm.

Figs. 34-43. Pygophore, ventral rim, ventral: 34, Brachystethus rubromaculatus; 35, B. signoreti; 36, B. cribrus; 37, B. schuhi; 38, B. tricolor; 39, B. vexillum; 40, B. geniculatus; 41, B. coxalis; 42, B. improvisus; 43, B. vicinus. Scale, 1 mm.

Figs. 44-52. Left paramere, posteroventral: 44, Brachystethus rubromaculatus; 45, B. signoreti; 46, B. cribrus; 47, B. schuhi; 48, B. tricolor; 49, B. vexillum; 50, B. geniculatus; 51, B. improvisus; 52, B. vicinus. Scale, 0.5 mm.