Graziasternum Roca-Cusachs & Rider, 2021

Roca-Cusachs, Marcos, Rider, Id. A. & Jung, Sunghoon, 2021, New genus and new species of Pentatomidae from Borneo (Hemiptera: Heteroptera), Zootaxa 4958 (1), pp. 560-569 : 561-562

Graziasternum Roca-Cusachs & Rider , gen. nov.

Type species: Graziasternum graziae sp. nov. by present designation.

Etymology: The genus Graziasternum is named after our friend and colleague Dr. Jocelia Grazia, to honour her 75th birthday, and in recognition of her prosperous career. The name Graziasternum is a combination of Dr. Grazia’s name, with the suffix – osternum, making reference to the flat, plate-like metasternum which it shares with the genus Placosternum . Gender is neuter.

Diagnosis. Graziasternum gen. nov. reassembles the genus Placosternum in the following characters: the prosternum has a slightly elevated, medial carina; the medial carina of the mesosternum is more distinctly carinate; the metasternum is broad, prominent, plate-like, hexagonal, with posterior angles projecting slightly towards abdomen; the abdominal base has a small, broad, anteriorly-directed, ventrally-flattened tubercle; and the abdomen has a medial, longitudinal, shallow, but clearly depressed, sulcus. There are, however, several characters that will serve to separate Graziasternum gen. nov. from Placosternum . For example, species of Graziasternum gen. nov. are characterized by having concolorous punctures which do not form patterns (dark punctures forming patterns in Placosternum ); by the absence of dark markings on the hemelytral membranes (dark hemelytral patterns present in Placosternum ); by the entire, non-serrate, acute humeral angles (multiple, serrate, and blunt in Placosternum ); by the pilosity on the legs (not pilose in Placosternum ); and by the absence of black punctured markings on the legs (present in Placosternum ); these characters clearly separate the two genera.

Description. Body somewhat flattened dorsoventrally, compact, heavily punctured. Colouration not forming mottled pattern, brown or yellowish brown with some reddish areas.

Juga longer than tylus, rounded apically. Anteocular teeth absent. Compound eyes protruding beyond head profile. Each ocellus located near base of adjacent compound eye, nearly contiguous with compound eye. Antennae five-segmented, apex of segment one reaching nearly to apex of head. Apex of rostrum surpassing procoxae, not reaching mesocoxae.

Anterior pronotal margins finely serrate; humeral angles, each slightly protruding beyond hemelytral base, acute, semi-spinose, entire (not toothed), slightly flattened towards apex. Scutellum distinctly longer than wide, basal angles, concolourous, foveate; scutellar apex narrow, clearly rounded. Hemelytra slightly covering mesial margins of connexiva; coria reddish, more or less contrasting with ground colouration; hemelytral membranes semi-hyaline, lacking black or coloured patterns; membranal veins marked. Peritremes elongate, slightly elevated, each rounded at apex, broadly L-shaped. Legs concolourous with ventral colouration, with hyaline, erect setae; tarsi 3-segmented. Prosternum broadly carinate; mesosternum distinctly carinate, not anteriorly produced; metasternum broad, prominent, ventrally flattened, hexagonal, with posterior angles slightly projecting caudad towards abdomen.

Connexivum uniformly coloured, finely punctate. Posterolateral angles of abdominal segments each slightly, but distinctly produced into minute, sharp denticle. Ventral surface of abdomen lightly coloured. Abdominal base directed anteriorly as broad, ventrally flattened tubercle apposed to notch in metasternal plate. Spiracles rounded, concolourous with abdomen. Abdomen with shallow, but clearly sulcate, medial longitudinal depression.

Pygophore trapezoidal, slightly elongate. Genital cup well exposed dorsally. Posterolateral angles of pygophore rounded, blunt, produced caudally. Ventral margin U-shaped. Dorsal rim concave, broadly U-shaped. Parameres compact, robust, simple.

Key to the species of Graziasternum gen. nov.

1 General colouration brownish, head and antennal segments IV and IV concolour with ground colouration, with no black markings. Ventral surface of pronotum with a broad, lateral, contrasting dark-red band along each anterolateral margin, together resembling an inverted V-shape................................................. Graziasternum graziae sp. nov.

- General colouration yellowish brown with contrasting dark red hemelytra, head with black markings and antennal segments IV and IV with clear blackish, contrasted ring at apex. Ventral surface of pronotum uniformly coloured............................................................................................... Graziasternum joceliae sp. nov.