Lineostethus acuminatus Kochenborger & Garbelotto, 2018

Garbelotto, Thereza de Almeida, Kochenborger, Ana Paula Leite & Campos, Luiz Alexandre, 2018, Revision of Lineostethus (Heteroptera: Pentatomidae: Discocephalini), Zoologia (e 21232) 35, pp. 1-24 : 16-18

Lineostethus acuminatus Kochenborger & Garbelotto , sp. nov.

http://zoobank.org/ 3E36196F-22D0-4FC2-8486-8E2BCCDCC36D

Figs 6, 54–61, 78

Diagnosis. Males of L. acuminatus sp. nov. differ from most species by the subtriangular expansions of the dorsal rim, although resembling L. graziae . L. acuminatus sp. nov. expansions are longer and narrower than L. graziae ( Figs 37, 54: fdr), and the dorsal rim cutting is U-shaped in L. acuminatus sp. nov. while subquadrangular in L. graziae ( Figs 37, 54: dr). Also, the projections of the superior layer of the ventral rim in L. acuminatus sp. nov. are uniformly wide and the apex is hook-shaped ( Fig. 55: psl). The phallus of L. acuminatus sp. nov. bears the largest vesica and the longest ductus seminis distalis in the genus ( Fig.59: v, ds). The females of the new species are recognized by the truncated apex of laterotergites IX and the posterior margin of segment X concave to subrectilinear ( Fig. 60: la9, X); the circular thickening of vaginal intima, the ductus receptaculi distal helicoid, and the pars intermedialis with an apical constriction help to identify this species ( Fig. 61: vi, ddr, pi).

Description. Antennae ivory; segments II–III with longitudinal brown lines. Anterolateral margins of pronotum and proximal portion of lateral margin of corium punctured in some specimens. Scutellum may present a spot of brown punctures on disc and on post-frenal lobe. Unpunctured area laterad to the apex of radial vein of coria smaller than the width of one eye. Hemelytral membrane reaching the apex of abdomen, with 6–7 veins. Ventrally, punctures sparse and laterally concentrated. Femora with sparse brown circular spots on distal half.

Male genitalia. Foliaceous expansions of dorsal rim subtriangular; apex of expansions rounded and surpassing the posterior limit of ventral rim; posterolateral angles visible dorsally ( Fig. 54: fdr, pa). Basal impression of the foliaceous expansions sinuous, cutting of dorsal rim U-shaped ( Fig. 54: bi, dr). Posterolateral angles rounded ( Figs 55–56: pa). Margin of the superior layer of ventral rim sinuous, median excavation drop-shaped ( Fig. 55: vr). Margin of the inferior layer of ventral rim with one subrectilinear line of short bristles ( Figs 55–56: b). Segment X with a line of setae on base ( Figs 54–55: X). Projections of the superior layer of ventral rim forming a right angle with posterolateral angles, covered by setae; dorsal margin convex and ventral margin concave; narrow at base, apex acute and hook-shaped, median third uniformly enlarged towards the apex ( Fig. 56: psl, pa). Parameres parallel or slightly directed to segment X, reaching the foliaceous expansions of dorsal rim; head lozenge ( Figs 56–58: par, X, fdr). Ventral surface of phallotheca concave ( Fig. 59: ph, ap). Vesica apex rounded; apical margin concave extending to mid of ductus seminis distalis ( Fig. 59: v, av, ds). Distal portion of ductus seminis distalis sinuous, about 2/3 longer than vesica, narrowing posteriorly ( Fig. 59: ds).

Female genitalia. Posterior margin of urosternite VII concave ( Fig. 60: VII). Gonocoxites VIII subtriangular; sutural and posterior margins subrectilinear ( Fig. 60: gcVIII). Posterior margin of laterotergites VIII slightly convex; limit between laterotergites VIII and tergite VIII indistinguishable ( Fig. 60: la8). Posterior margin of gonocoxites IX subrectilinear ( Fig. 60: gcIX). Laterotergites IX digitiform and truncate apex; mesial and lateral margins convex ( Fig. 60: la9). Posterior margin of segment X concave to rectilinear ( Fig. 60: X). Thickening of gonapophyses IX subrectangular, not surpassing the lateral margin of the thickening of vaginal intima ( Fig. 61: gpIX, tgIX). Thickening of vaginal intima circular and flat ( Fig. 61: vi). Distal portion of ductus receptaculi helicoid ( Fig. 61: ddr); anterior annular crest turned to ductus receptaculi; pars intermedialis with a shallow constriction on its apex and subequal in length to capsula seminalis; posterior annular crest perpendicular to pars intermedialis ( Fig. 61: pi, cs). Capsula seminalis shallowly constricted near base ( Fig. 61: cs).

Measurements. Male (n = 5): head length, 1.54 ± 0.07 (1.43–1.63); width, 2.96 ± 0.16 (2.70–3.10); length of antennal segments: I, 0.40 ± 0.01 (0.40–0.42); II, 0.68 ± 0.04 (0.62–0.70); III, 0.67 ± 0.06 (0.60–0.74); IV, 0.89 ± 0.01 (0.88–0.90); V, 1.05 ± 0.07 (1.00–1.10); length of labial segments: I, 0.66 ± 0.05 (0.60–0.70); II, 1.34 ± 0.05 (1.30–1.40); III, 0.63 ± 0.05 (0.58–0.70); IV, 0.46 ± 0.05 (0.38–0.50); pronotum length, 1.66 ± 0.11 (1.52–1.80); width, 3.95 ± 0.18 (3.65–4.10); scutellum length, 3.30 ± 0.15 (3.08–3.48); width, 2.61 ± 0.12 (2.42–2.73); total length, 6.26 ± 0.30 (6.32–6.53); abdominal width, 4.28 ± 0.19 (4.00–4.45).

Female (n = 5): head length, 1.55 ± 0.06 (1.45–1.63); width, 3.09 ± 0.13 (2.95–3.24); length of antennal segments: I, 0.42 ± 0.02 (0.40–0.46); II, 0.71 ± 0.06 (0.64–0.78); III, 0.65 ± 0.04 (0.60–0.70); IV, 0.81 ± 0.07 (0.74–0.90); V, 0.96 ± 0.03 (0.94–1.00); length of labial segments: I, 0.67 ± 0.04 (0.60– 0.70); II, 1.39 ± 0.08 (1.26–1.48); III, 0.65 ± 0.09 (0.60–0.80); IV, 0.43 ± 0.04 (0.40–0.48); pronotum length, 1.76 ± 0.08 (1.62–1.82); width, 4.07 ± 0.13 (3.88–4.20); scutellum length, 3.36 ± 0.08 (3.28–3.44); width, 2.68 ± 0.10 (2.64–2.79); total length, 6.67 ± 0.19 (6.60–6.96); abdominal width, 4.52 ± 0.14 (4.30–4.65).

Type material. Holotype (male): COSTA RICA, Guanacaste: Santa Rosa (NP, Research Station 308.1, 10.81N 85.62W), 7-XII-2008, Weirauch & Forero leg. (deposited in: DZUP) . Paratypes: HONDURAS: El Paraiso: Zamorano , 1 male, 28-VII-1977, O’Brien leg. ( DARC) . COSTA RICA: (C.a. E.P.), 1 male, no date ( CAS) ; Guanacaste: Las Cañas ( Finca La Taboga ), 1 female, 17- 27-VI-1969, Toby Schuh, Janet Crane leg. ( AMNH) ; Santa Rosa (NP, Research Station , 308m, 10.84°N 85.62°W), 2 males and 4 females, 06-XII-2008, Weirauch & Forero leg. ( UCRC) ; Palo Verde National Park ( Nr OTS research station 26m, 10.35°N 85.35°W), 3 males and 8 females, 4-XII-2008, Weirauch & Forero leg. ( UFRG) . PANAMA, Los Santos: Taboga , 1 male, XII-1953, Collector: N.L.H. Kraus leg. ( AMNH) .

Distribution ( Fig. 78). Honduras: El Paraiso; Costa Rica: Guanacaste; Panama: Los Santos.

Etymology. The epithet refers to the shape of the apex of each projection of the superior layer of ventral rim of pygophore; Latin adjective masculine, acuminatus (-a, -um) = pointed, sharpened.