Amblycerus truncatus Ribeiro-Costa, 2025

Amblycerus truncatus Ribeiro-Costa sp. nov.

Figs 1 A – H View Figure 1 , 2 A, B View Figure 2 ; Table 1 View Table 1

Type material.

Holotype • Deposited in DZUP with labels: Sinop-MT-Brasil \ 12-14/I/2000 \ Caseiro, F. T. col., [white label, printed in black]; Planta hospedeira \ Dimorphandra macrostachya [white label, printed in black]; HOLOTYPE \ Amblycerus truncatus \ Ribeiro-Costa, [white label with red margin, printed in black] . Paratypes • ( n = 5) with the same data as holotype, PARATYPE \ Amblycerus truncatus \ Ribeiro-Costa [white label with yellow margin, printed in black]. Two paratypes deposited in DZUP and three paratypes in USDC .

Diagnosis.

Amblycerus truncatus Ribeiro-Costa , sp. nov. is the unique species in the group sclerolobii with truncate scutellum at apex (Fig. 1 B View Figure 1 ) and can easily be identified by this character; the other species in the group have scutellum tridentate, with all teeth the same size. The internal characters of male genitalia also distinguish this species, mainly the unique sclerite at AR of internal sac U-shaped inverted with the stems further apart or only the transverse part of the U (Fig. 2 A View Figure 2 ).

Description

. Dimensions: BL: 7.50–8.10 mm (x ̄ = 7.86 mm; n = 6); BW: 4.70–5.00 mm (x ̄ = 4.92 mm; n = 6)

Integument color: Reddish brown in following areas: first two antennomeres, apex of clypeus, labrum, pronotum, elytra, pygidium, metanepisternum, abdominal ventrites on lateral areas and first, middle legs and hind coxae. Dark brown: part of head, antennomeres except first two, thorax ventrites, abdominal ventrites on middle region and hind leg except coxae. Sometimes specimens entirely darker or paler but in general keep the contrast of colors, at least on antennomeres.

Vestiture: Dorsum covered with yellowish pubescence evenly distributed, sometimes whitish on darker integument; pygidium sometimes with faint dense median line of setae.

Head: Covered with fine and dense punctures, except clypeus at apex and middle to apex of labrum; punctures gently finer on vertex and coarser on clypeus. Frons convex, frontal carina absent, finely punctate or smooth line on midline, sometimes evanescent basally. Eye coarsely faceted, strongly prominent laterally. Ocular index 4.2; ocular sinus 0.1 of the eye length in lateral view; postocular lobe 0.2 the eye length. Antennae with antennomeres elongate except 2 ~ 1 / 3 the length of 1, moderately serrate from antennomeres 4–10; 11 elongate-acuminate. Frontoclypeal suture conspicuous. Prothorax: Pronotum semicircular, disk moderately convex, with lateral margins moderately arcuate in dorsal view, median basal lobe delimited, not carinate; cervical sulcus on 1 / 3 lateral reaching cervical boss with trichobothria; disc with fine and dense punctures, moderately coarse punctures on lateral areas; lateral carina almost reaching the anterior margin of pronotum. Prosternal process narrow, apex slightly expanded and gently beyond anterior coxae. Mesothorax and metathorax: Scutellum 1.3 longer than wide with truncate apex. Elytron 2.6 × longer than wide; striae composed of fine punctures joined in lines; all free apically except third and eighth joined; strial intervals only with fine punctures, somewhat flat medially, truncate apically. Mesoventrite truncate apically. Metanepisternum with only fine punctures, lacking striate file; metepisternal sulcus forming right angle, vertical axis not reaching the margin of metepisternum, longitudinal axis less than a half the length of metepisternum. Metaventrite with dense and fine punctures, without coarse punctures, not protuberant between mid coxae, median sulcus extending laterally a half or more than a half the length of metaventrite. Hind coxae with fine dense punctures; moderately coarse, sparse punctures on distal two-thirds. Hind femur slender, ~ 2.82 × longer than wide. Hind tibia with coronal denticles of about equal length; lateral spur ~ 2.36 × the length of median spur. First tarsomere ~ 1.20 the length of lateral spur and 2.84 × the length of median spur. Abdomen: Pygidium basal 1 / 3 covered by the elytra, with moderately coarse and dense punctures, apex subtruncate in males and subacute in females. Ventrites with moderately coarse, sparse punctures on lateral areas, last ventrite longer than ventrive IV, gently emarginate in male, rounded in female.

Male terminalia: Tergite VIII subsquare, subtruncate at apex. Median lobe ~ 3.95 × its widest at apical region; dorsal valve 0.73 × wider than long, subtriangular, lateral margins gently curved, apex rounded; ventral valve 1.59 × wider than long, lateral margins emarginate, apex acute. Armature of internal sac, AR with one sclerite U- shaped inverted with the stems further apart or only the transverse part of the U. MR with a pair of long, laminar, straight sclerites, outer margin serrate along its middle apical 0.5 length; wishbone-shaped sclerite 0.42 as long as the laminar sclerites length, gently curved, apex projected, subtruncate in lateral view or wishbone-shaped sclerite with similar form, less than half its length. BR with one sclerite with long stems gradually approximates. Tegmen with lateral lobes cleft to 1 / 12 of their length, strongly expanded laterally.

Etymology.

The specific name, an adjective in the nominative case, is Latin for truncate in reference to the shape of the scutellum of this species.

Distribution.

Brazil (Mato Grosso-Sinop)

Host plant.

Fabaceae : Dimorphandra macrostachya Benth.