Lineostethus tenebricornis ( Ruckes, 1957 )

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 : 8-10

Lineostethus tenebricornis ( Ruckes, 1957)

Figs 2, 19–26, 78

Platycarenus (Discocephalessa) tenebricornis Ruckes, 1957: 16–17 . Lineostethus tenebricornis : Ruckes (1966: 24); Hildebrand and

Becker (1982: 778–780).

Diagnosis. The specimens of L. tenebricornis may have brown antennae, also observed in L. auritus sp. nov. and L. otarus sp. nov. The males of L. tenebricornis are recognized by the subquadrangular foliaceous expansions of the dorsal rim of pygophore, covering dorsally the posterolateral angles ( Figs 19–21: fdr, pa); the projections of the superior layer of ventral rim elongate and rounded at apex (the last feature similar to L. graziae ) ( Figs 21, 39: psl); the presence of two lines of short bristles below the projections of the superior layer of ventral rim ( Figs 20–21: b); and the apical margin of vesica along with the ductus seminis distalis ( Fig. 24: av, ds). In the females, diagnostic features are the posterior margin of urosternite VII subrectilinear on its median third along with subrectangular gonocoxites VIII ( Fig. 25: VII, gcVIII); and the thickening of gonapophysis IX subrectangular with a median constriction, combined with a subtriangular thickening of vaginal intima ( Fig. 25: tgIX, vi). The median third of the posterior margin of urosternite VII and the subtriangular thickening of vaginal intima are also found in L. otarus sp. nov. However, L. tenebricornis has shallower genital plates than L. otarus sp. nov. ( Figs 25, 68), and the thickenings of gonapophysis IX have different shapes ( Figs 26, 69: tgIX, vi).

Redescription. Antennal segments usually brown, sometimes ivory with longitudinal brown line on segments I–II; segment III usually longer than II. Anterolateral margins of pronotum and proximal portion of lateral margin of corium punctured. Unpunctured area laterad to the apex of radial vein of coria smaller than the width of one eye. Hemelytral membrane at least reaching the apex of abdomen, with 8 veins. Ventrally, punctures uniformly distributed. Femora with brown circular spots on the entire length or concentrated on distal half.

Male genitalia. Foliaceous expansions of dorsal rim subquadrangular; apex of expansions surpassing the posterior limit of ventral rim, hiding the posterolateral angles ( Fig. 19: fdr). Basal impression of the foliaceous expansions subrectilinear, cutting of dorsal rim subrectangular, filled by the parameres and segment X ( Fig. 19: bi, dr, pa, X). Posterolateral angles with sinuous apex ( Figs 20–21: pa). Margin of the superior layer of ventral rim concave, median excavation U-shaped ( Fig. 20: vr). Margin of the inferior layer of ventral rim with two subrectilinear lines of short bristles ( Figs 20–21: b). Projections of the superior layer of ventral rim forming a right angle with the posterolateral angles; projections thin at base, median portion enlarged, and apex elongate; setae on the posterior margin of the projections ( Fig. 21: psl, pa). Apex of parameres diverging, reaching or surpassing the foliaceous expansions of dorsal rim; head subtriangular with acute apex ( Figs 21–23: par, X, fdr). Ventral surface of phallotheca concave ( Fig. 24: ph, ap). Vesica more sclerotized on middle and over the ductus seminis distalis; apex of vesica concave; apical margin, concave, accompanying the ductus seminis distalis ( Fig. 24: v, av, ds). Distal portion of ductus seminis distalis shorter than vesica ( Fig. 24: ds).

Female genitalia. Posterior margin of urosternite VII slightly sinuous, middle third subrectilinear and lateral thirds convex ( Fig. 25: VII). Gonocoxites VIII subrectangular; posterior margin slightly convex and sutural angles weakly divergent and basal two thirds of sutural margins juxtaposed ( Fig. 25: gcVIII). Posterior margin of laterotergites VIII convex and limit between laterotergites VIII and tergite VIII indistinguishable ( Fig. 25: la8). Posterior margin of gonocoxites IX slightly concave ( Fig. 25: gcIX). Laterotergites IX digitiform ( Fig. 25: la9). Posterior margin of segment X subrectilinear to concave ( Fig. 25: X). Thickening of gonapophyses IX subrectangular narrowed medially, surpassing the lateral margin of the thickening of vaginal intima ( Fig. 26: gpIX, tgIX). Thickening of vaginal intima subtriangular ( Fig. 26: vi). Distal portion of ductus receptaculi medially sclerotized and enlarged ( Fig. 26: ddr); anterior annular crest perpendicular to pars intermedialis; pars intermedialis sclerotized on basal two thirds and subequal to capsula seminalis in length; posterior annular crest turned to capsula seminalis ( Fig. 26: pi, cs). Capsula seminalis with slight basal constriction ( Fig. 26: cs).

Measurements. Male (n = 5): head length, 1.59 ± 0.05 (1.53–1.68); width, 2.96 ± 0.04 (2.88–3.01); length of antennal segments: I, 0.44 ± 0.04 (0.42–0.48); II, 0.76 ± 0.06 (0.72–0.82); III, 0.79 ± 0.06 (0.70–0.86); IV, 0.96 ± 0.05 (0.88–1.00); V, 1.17 ± 0.05 (1.08–1.22); length of labial segments: I, 0.76 ± 0.01 (0.76–0.78); II, 1.58 ± 0.05 (1.50–1.64); III, 0.68 ± 0.05 (0.62–0.74); IV, 0.51 ± 0.02 (0.50–0.54); pronotum length, 1.72 ± 0.06 (1.66–1.80); width, 4.24 ± 0.13 (4.10–4.45); scutellum length, 3.30 ± 0.20 (3.04–3.52); width, 2.71 ± 0.05 (2.67–2.79); total length, 6.82 ± 0.12 (6.67–7.03); abdominal width, 4.83 ± 0.12 (4.65–4.95).

Female (n = 5): head length, 1.56 ± 0.06 (1.5–1.63); width, 2.99 ± 0.08 (2.91–3.10); length of antennal segments: I, 0.43 ± 0.02 (0.40–0.46); II, 0.81 ± 0.04 (0.78–0.86); III, 0.82 ± 0.04 (0.80–0.86); IV, 1.02 ± 0.06 (1.00–1.12); V, 1.10 ± 0.20 (0.90–1.28); length of labial segments: I, 0.82 ± 0.04 (0.76–0.88); II, 1.60 ± 0.03 (0.02–1.64); III, 0.73 ± 0.03 (0.70–0.78); IV, 0.56 ± 0.03 (0.54–0.60); pronotum length, 1.89 ± 0.07 (1.82–1.98); width, 4.47 ± 0.08 (4.40–4.60); scutellum length, 3.66 ± 0.08 (3.60–3.80); width, 2.80 ± 0.16 (2.79–2.95); total length, 8.21 ± 0.74 (6.96–8.90); abdominal width, 5.10 ± 0.22 (5.00–5.48).

Material examamined. Paratypes: USA, Arizona: San Rita Mt , 1 female, 11-VII-1932, E.D. Ball leg. ( AMNH) ; Madera Cyn. (Sta Rita Mts Pima Co.), 1 male, 13-VIII-1952, M. Cazier, R. Schrammel, C. & P. Vaurie leg. ( CAS) ; Runaway Canyon Huachuca mts. , 1 female, 15-I-1941 ( AMNH) ; Huachuca Mts. (Rd to Petersens Rch ), 1 female, 17-VIII-1940, E.C. Van Dyke leg. ( CAS) ; Atascosa Mt. , 1 female, 19-VII-1935, E.D. Ball leg. ( AMNH) . Other specimens: USA, Arizona: ( Nr Oracle ), 1 female, 14-VII-1940 ( CAS) ; Sabino Cañon, Santa catalina Mts (4200 ft, on wild cotton), 1 male, 28-XI-1913, HSB leg.( USNM); ( Cave Cr Chiricahua Mts. ) , 1 male and 2 females, 4-VII-1930, Pres. By. G. Linsley Collector leg. ( CAS); ( Cave Crk. Chiricahua Mts. ) , 1 male, 20-VI-1932, J.O. Martia leg. ( CAS) ; Cochise Co., ( Chiricahua Mts Horseshoe Cany ), 6 males and 6 females, 4-VII-1977, Scott McCleve leg. ( AMNH) ; Cochise Co., ( Chiricahua Mts Horseshoe Cany ), 1 male, 4-VII-1977, Scott McCleve, M. Cazier, R. Schrammel, C. & P. Vaurie Collectors leg. ( AMNH) ; Cochise Co. Chiricahua Mts. ( South Fork ), 1 male and 1 female, 12-VIII-1978, Duane / Pam Flynn leg. ( DARC) ; Cochise Co. Chiricahua Mts. ( South Fork ), 1 female, 12-VIII-1978, Duane / Pam Flynn leg. ( DARC) ; Cochise Co. Huachuca Mts ( Ash. Canyon , 5600- 6000), 1 male, 29-VII-1979, W.F.Barr leg. ( DARC) ; Cochise Co. Huachuca Mts ( Ash. Canyon , 5600-6000), 1 female, 29-VII-1979, W.F.Barr leg. ( DARC) ; Huachuca Mts , 1 female, 3-VII-2005 ( CAS) ; Huachuca Mts , 1 male, 16-VII-2005 ( CAS) ; Huachuca Mts. (Rd to Petersens Rch ), 2 males and 1 female, 17-VIII-1940, E.C. Van Dyke leg. ( CAS) ; Huachuca Mts. ( Carr Cn ), 2 males and 1 female, 7-VIII-1924, E.P. Van Duzee leg. ( CAS) ; Huachuca Mts , 1 male, VII-1905, H.G. Barber Colln 1950 leg. ( USNM) ; Cochise Co. ( Cave Creek Cyn. 3 mi WE Portal), 1 male, 6-IX-1979, H.A.Hespenheide leg. ( DARC) ; Cochise Co. (SW Res. Sta. 5mi W Portal), 5 females, 10-11-VIII-1983, E.G. & M. Riley leg. ( DARC) ; Cochise Co. Chiracahua Mtns ( Cave CK.), 1 female, 27-VIII-1983, D.B.Thomas leg. ( DARC) ; Cochise Co. Chiracahua Mtns ( Cave CK.), 1 male, 27-VIII-1983, D.B.Thomas leg. ( DARC) ; Madera Cn. , (Santa Rita Mts. Santa Cruz Co. 6200ft.), 2 males and 3 females, 1-2-VIII-1952, H.B. Leech & J.W. Green Collectors leg. ( CAS) ; Florida Cn., 2 males, 10-VIII-1924, Santa Rita Mts , E.P. Van Duzee Collector leg. ( CAS) ; Palmerlei, 1 female, July, H.G. Barber Collector leg. ( USNM); (Camp Washington Patagonia Mts. ) , 1 male, 22-VI-1948, H.S.B. Barber leg. Request 1950 ( USNM) .

Distribution ( Fig. 78). USA: Arizona ( Ruckes 1957, 1966, Hildebrand and Becker 1982). Mexico: Michoacán ( Hildebrand and Becker 1982).

Remarks. From the data retrieved of specimens’ labels, cotton ( Gossypium hirsutum L., Malvaceae ) is a possible host plant.