Tynacantha Dallas, 1851

Tynacantha Dallas, 1851: 106; Stål, 1867: 497; Walker, 1867: 144; Stål, 1870: 56; Schouteden, 1907: 13, 59; Kirkaldy, 1909: 5, 16; Thomas, 1992: 122.

Type species: Tynacantha marginata Dallas, 1851, by monotypy

Diagnosis. Anterolateral margins of pronotum rectilinear, concolorous with ventral surface and unpunctured; humeral angles acute, not produced; abdominal spine reaching at most the anterior margin of metacoxae; abdominal venter minutely punctured (Figs 1–2, 4–5, 7–18). Peritreme groove-shaped, surrounded by evaporatorium. Superior layer of ventral rim of pygophore with 1 + 1 acute processes (Figs 20, 25, 30), dorsal rim concave with 1 + 1 sinuous projections (Figs 19, 24, 29). Head of paramere with two branches (Figs 22, 27, 32); capsula seminalis globose; thickening of vaginal intima tube-like with an anterior elliptic projection (Figs 48, 51).

Redescription. Body oval; brown or dark brown dorsally, frequently bright green; ventrally pale yellow, sometimes orange with two or three rows of black spots; legs pale yellow or orange, immaculate (Figs 1–2, 4–5, 7–18). Head: rectangular; as long as wide or slightly wider than long; clypeus slightly longer than mandibular plates (Figs 9, 12, 15, 18). Labium slightly surpassing the metacoxae, second segment longest. Antennae five-segmented, second segment the longest. Thorax: anterolateral angles of pronotum produced; anterolateral margins of pronotum rectilinear, concolorous with ventral surface and unpunctured; humeral angles acute, not produced (Figs 9, 12, 15, 18). Basal angles of scutellum foveate; frenal margin of scutellum longer than postfrenal margin, apex of scutellum pale calloused or concolorous, reaching the fifth segment of abdomen. Peritreme groove-shaped, apex curved anteriorly and usually with a black spot; evaporatorium on metapleuron surrounding the peritreme, not extending to the lateral margin of thorax; evaporatorium extended onto posterior margin of mesopleuron. Membrane of hemelytra brownish medially or entirely translucent. Abdomen: ventral surface unpunctured; abdominal spine reaching at most the anterior margin of metacoxae. Connexival segments brown to dark brown anteriorly and posteriorly, with the medial part pale, or with a lateral line concolorous with the abdominal sternites. Margin of spiracles concolorous with venter. Male genitalia (Figs 19–45): Pygophore wider than long; dorsal rim concave, with 1 + 1 projections; inferior layer of ventral rim concave; superior layer of ventral rim concave with 1 + 1 acute processes, convex laterally; parameres with two branches, ventral surface of the internal branch sculptured; superior process of dorsal rim semicircular, with rounded sculptures dorsally; segment X subrectangular; thecal shield longer and wider than basal theca; apex of conjunctival lobes slightly sclerotized; vesica cup-like with 1+1 tabs laterally; secondary gonopore projected. Female genitalia (Figs 46–53): Gonocoxites VIII as long as wide, laterotergites VIII triangular; gonocoxites IX rectangular, lateral margins projected over the laterotergites IX; laterotergites IX longer than wide, surpassing the segment X, reaching the sclerite VIII; gonapophyses IX with 1+1 slightly sclerotized areas surrounding the ring sclerites; ring sclerites circular; 1+1 secondary thickenings of gonapophyses IX crescent-like; thickening of vaginal intima tube-like with an anterior elliptic projection; capsula seminalis globose; anterior and posterior annular flanges projected posteriorly; ductus receptaculi proximalis longer than vesicular area.

Remarks. The bright color and the black spots on the ventral surface of abdomen can change after preservation (see Discussion).

Key to species of Tynacantha Dallas, 1851

1 Apex of scutellum without a pale and calloused spot; segments of connexivum not alternated, lateral margin concolorous with the abdominal sternites (Figs 1, 7)......................................................... T. marginata Dallas

- Apex of scutellum with a pale and calloused spot; segments of connexivum alternated brown to dark brown anteriorly and posteriorly, medial area pale (Figs 4, 10, 13, 16)............................................................. 2

2 Membrane of hemelytra entirely translucent; pale and calloused spot at apex of scutellum occupying half of the postfrenal lobe (Central America) (Figs 4, 10)............................................................ T. splendens Distant

- Membrane of hemelytra brownish medially; pale and calloused spot of scutellum restricted to the apex of postfrenal lobe (South America) (Figs 13, 16)................................................................................. 3

3 Humeral angles distinctly black and punctured (Fig. 18); intersegmental areas of connexivum light brown; posterior margins of gonocoxites VIII sinuous (Fig. 53).................................... T. umeridenigrata Brugnera & Grazia sp. nov.

- Humeral angles concolorous with pronotum, unpunctured (Fig. 15); intersegmental areas of connexivum black; posterior margins of gonocoxites VIII almost rectilinear (Fig. 50)............................. T. cuprea Brugnera & Grazia sp. nov.