Belostoma utiaritiensis Stefanello & Carpintero & Mulieri 2025, new species

Belostoma utiaritiensis Stefanello, new species (Figs. 1–3) Description. Male, HOLOTYPE, body length 32.80; maximum width 14.90. General shape elliptical to ovoid, widest at mid-length of hemelytra; overall dorsal coloration maroon, with mesal part of pronotum and scutellum light-brown. Ventral surface brown (Fig. 1A,B). Head. Eyes subtriangular, lateral margin almost straight (Fig. 1A). Interocular space 1.40× width of an eye, interocular space 2.75, eye 1.95; anteoculus 1.05× interoculus, anteoculus 2.30, interoculus 2.20. Vertex without median carina. Maxillary plate with dorsal and ventral ends straight, not projected forward, covered with golden setae. Lorogenal cleft without conspicuous fovea. Antenna four-articulated, with lateral projections well-developed. Labium long, four-articulated; article II 0.72× length of III, II 2.55, III 3.55. Thorax. Pronotum without median carina; a pair of depressed rounded areas on disc at anterior half; transverse sulcus setting off band on posterior third; finely rugose, mainly on posterior third behind transverse sulcus; anterior margin concave medially; lateral margin shallowly concave, with a narrow fold extending to posterior portion; posterolateral corner right-angled; posterior margin shallowly concave medially, slightly angulated laterally; maximum width about 2.0× length at midline, maximum width 11.05 (across posterolateral corners), length at midline 5.60. Prosternal keel well-developed, projected forward, with apex pointed (Fig. 1D). Scutellum finely rugulose, mainly on posterior region; a pair of elevations near midline at anterior half; length at midline 6.75, maximum width 7.05. Hemelytra finely punctate throughout; embolar groove (=nodal suture) present reaching second abdominal segment; membrane well-developed; hind wing with Mp and CuA veins merging at distal third; R+Ma gently curved posteriorly at apex; wing groove of mesoscutellum widened, slightly convex. Mesepimeral projection extending posteriorly in dorsal view, reaching middle of abdominal tergum II; wing knob rounded. Metanotum densely pubescent. Postalar metathoracic projection with lateral margin folded downward, gutter-shaped; length of postalar projection 0.85× length of mesepimeral projection. Metaxyphus swollen medially at anterior two-thirds, slightly depressed at posterior third, with distolateral margins converging at apex, forming an acuminate point. Legs. Protibia at mid-length with lateral surface slightly narrower than mesal surface. Middle and hind legs light-brown with dark spots. Measurements as follows: foreleg, femur 6.30, tibia 4.20, tarsomeres lost; middle leg, femur 6.95, tibia 6.60, tarsomeres 1–3 lost; hind leg, femur 8.10, tibia 9.00, tarsomeres 1–3 4.75. Abdomen. Pubescence covering connexiva and mediosternites of abdominal segments II–VII (Fig. 1B). Airstraps lanceolate, linear, slightly constricted at mid-length, without dorsal sac. Male genitalia: Paramere elongate, narrowing towards apex, which is distinctly twisted upward and mesad. Dorsal arms of phallosoma convergent, entirely covering diverticulum in dorsal view (Fig. 1E); phallosoma weakly curved in lateral view, without dorsocaudal elevation (Fig. 1F); diverticulum elliptical, with apex straight, and folded ventrally forming an apicoventral protuberance also visible in lateral view (Fig. 1F, G). Female unknown. Diagnosis. This species can be easily recognized by the following combination of characters: broad species; eye triangular, with lateral margin almost straight; prosternal keel elevated with apex pointed; lateral margins of pronotum shallowly concave; article II of labium shorter than III, abdominal pubescence entirely covering connexiva and mediosternites; dorsal arms of phallosoma convergent apically and diverticulum folded apically forming an apicoventral protuberance. Comparative notes. Belostoma utiaritiensis sp. nov. clearly resembles other congeners belonging to the Belostoma fittkaui group. However, the new species differs in differs in having an elevated prosternal keel with a pointed apex, whereas in the others, the apex is rounded; eyes with lateral margins slightly less straight when compared to B. fittkaui, which is similar in body shape; and diverticulum of the phallosoma folded at the apex and forming an apicoventral protuberance, which is unique within the group. The PCA results based on linear measurements indicate that the evaluated species, including the new species, are distributed in distinct clusters within three-dimensional morphospace, except B. bergi and B. costalimai (Fig. 2). PC1 was related to aspects of size and accounted for 91.6% of the interindividual variation, PC2 and PC3 were associated with the lengths of the labial articles II and III and accounted for 5.26% and 0.90% of the interindividual variation, respectively (Table 1). PCA effectively distinguished B. utiaritiensis sp. nov. from its congeners, including species in the Belostoma fittkaui group (B. fittkaui, B. sayagoi, and B. zecai). Etymology. The specific epithet “ utiaritiensis ” refers to the type locality, which is in the Utiariti Indigenous Land. Distribution. This species is known only from the type locality, the Papagaio River in the state of Mato Grosso, in central-western Brazil (Fig. 3A). Currently, this area belongs to the Utiariti Indigenous Land (Decree 261 – 10/29/1991). Type material. HOLOTYPE, ♂: BRAZIL, Mato Grosso, Utiariti, Papagaio River, 24.xi.1966. Williner, S. J. coll. MACN _ En 41988 (MACN) (Fig 1C).