Belostoma testaceopallidum Latreille. Three 1807

Belostoma testaceopallidum Latreille, 1807

(Figs 15; 21B; 25)

Belostoma testaceopallidum Latreille, 1807: 144.

Zaitha stolli: Mayr 1863 [questionable]: 352 (not Amyot & Serville).

Zaitha margineguttata Dufour, 1863 [questionable]: 387.

Zaitha carbonaria Dufour, 1863 [questionable]: 388.

Belostoma grandicollum De Carlo, 1934: 109. Syn. n.

Belostoma longirostrum De Carlo, 1934: 110 (Fig. 2).

Belostoma stolli: De Carlo 1950: 531.

Types.— Belostoma testaceopallidum was described on the basis of specimens [unknown locality] which have been lost, and thus Lauck (1963) proposed a male neotype (Curitiba, Paraná) deposited in USNM [not examined].

Material examined.— ARGENTINA. * 1 m (MACN 7932): Misiones, Garuhape, 13.I.1966, (A. O. Bachmann), J. A. de Carlo det. 1 m (MACN 5653): same, San Ignacio, XI.1940, (A. Zotta), J. A. de Carlo det., J. R. I. Ribeiro det. 1999. BRAZIL. Mato Grosso — 1 m (MNRJ 117): [without a more precise locality], 1918, (J. G. Keihlmam), J. A. de Carlo det. as B. grandicollum, J. R. I. Ribeiro det. 1999, B. grandicollum holotype . Minas Gerais — *1 f (DZRJ-a 468): Lima Duarte, Parque Estadual Ibitipoca [vegetation at the edge of river], 06.XI.1993, (R. L. C. Baptista), J. R. I. Ribeiro det. 1999. Rio de Janeiro — 1 m (MNRJ 116): Teresópolis, 06.III.1918, (M. Ribeiro), J. A. de Carlo det. as B. longirostrum, J. A. de Carlo det., B. longirostrum holotype . * 1 m [with eggs on dorsum] (DZRJ-a 467): Teresópolis, “Faz. Vale da Revolta”, 02.IX.1989, (R. Sachse), J. R. I. Ribeiro det. 1999. 1 f (DZRJ 3): same, Serra do Subaio [“represa acima”], 06. VI.1996, (E. C. Mendonça), J. R. I. Ribeiro det. 1999. 1 f (DZRJ-a 352): same, Subaio, 06–09. VI.1996, (“Equipe entomologia” [J. R. I. Ribeiro]), J. R. I. Ribeiro det. 1999. Santa Catarina — *1 f (SEMC): Nova Teutônia [27 o 11’ S, 52 o 23’ W, 300–500 m], 29.IX.1955, (F. Plaumann), J. T. Polhemus det. as B. grandicollum, J. R. I. Ribeiro det. 1999.

Distribution.— ARGENTINA: Misiones (De Carlo 1930). BRAZIL (Dufour 1863): Bahia [?] (Dufour 1863), Mato Grosso (De Carlo 1938), Minas Gerais (De Carlo 1938), Paraná (Lauck 1963), Rio de Janeiro (De Carlo 1934), Santa Catarina (Ribeiro 2005), São Paulo (De Carlo 1938). LESSER ANTILLES[?]: Guadalupe (Mayr 1871).

Description.—Measurements (m / f). Total length (from apex of head to apex of hemelytra at rest) 29.7– 34.1 / 26.6–33.5; largest width of body 15.3–17.0 / 13.4–16.3; median length of pronotum 4.48–5.00 / 4.00– 5.12; greatest pronotal width 8.80–10.00 / 8.00–10.24.

General coloration yellowish brown.

Body elliptical. Length of anteoculus 1.12–1.55 times length of interoculus; length of rostral segment I 0.71–0.93 times length of segment II; anterior frontogenal suture equal to longer than posterior frontogenal suture; clypeus reaching or not reaching ocular line (0–0.64 mm); vertex without longitudinal median carina; posterior interocular width 1.24–1.50 times length of anteoculus, and from 1.64 to 1.75 times width of eye; eyes rounded. Pronotum usually beset with longitudinal median carina on its posteriorly; greatest pronotal width 1.96– 2.00 times its length; scutellum reaching or not reaching nodal line (0–0.32 mm), usually with parallel lateral carinae; prosternal keel prominent, triangular, acute at apex (Fig. 15A). Pilosity extending along genital operculum, covering entire margin of connexivum and all or part of sternites.

Male genitalia (Fig. 15B–D).—Caudal portion of phallus flattened. Dorsal arms slightly convergent, neither narrowing nor broading, rounded at apex in dorsal view; ventral diverticulum without dorsal caudal protuberance in dorsal and lateral views, and without ventroapical protuberance in lateral and ventral views; caudal lateral margins of ventral diverticulum sinuous (LAS), not convex in ventral view; width of ventral diverticulum about 1.25 times its length in ventral view.

Variation.—I have seen specimens from Misiones, Argentina, with a shorter body (26.6 mm), and with the caudal lateral margins of ventral diverticulum only weakly sinuous in ventral view (Fig. 15E–G).

Notes on biology.—Like B. ribeiroi, and according to Nieser and Melo (1997), B. testaceopallidum has been most often collected at the edges of running waters. Moreover, it seems to be a rare species and apparently confined to the southern half of Brazil and to northern Argentina (Nieser 1975).

Comparative notes.— Belostoma grandicollum keys to B. testaceopallidum in Nieser and Melo’s (1997: 59) key. Its phallus and greatest pronotal width, about twice its length, are similar to those of B. testaceopallidum. The differences between the types I examined are small and well within the limits of variability found for B. testaceopallidum specimens studied in this review. I therefore am confident in synonymizing B. grandicollum with B. testaceopallidum.