Belostoma sanctulum Montandon, 1903

Ribeiro, Josė Ricardo Inacio, 2007, A review of the species of Belostoma Latreille, 1807 (Hemiptera: Heteroptera: Belostomatidae) from the four southeastern Brazilian states, Zootaxa 1477 (1), pp. 1-70 : 42-43

Belostoma sanctulum Montandon, 1903

( Figs 11J–N ; 20D ; 24B )

Belostoma sanctulum Montandon, 1903b: 362 .

Belostoma amici : Piza-Jr. 1975 [in part]: 67.

Types.— Belostoma sanctulum was described based on syntypes (Espírito Santo) deposited in HNHM, in ISNB, and in Breddin’s collection (see Schnack [1976]: 41). Estévez (1996: 56) designated a male syntype deposited in HNHM as lectotype and another male syntype (Espírito Santo) deposited in NHMW, as paralectotype. These specimens have not been examined.

Material examined.— BRAZIL. Espírito Santo — * 1 m ( HNHM): [without a more precise locality], 1903, ([?] Fruhstorfer), A. L. Montandon det. 1903, D. R. Lauck det. 1959. * 2 m ( ISNB): [without a more precise locality], 1903, ([?] Fruhstorfer), A. L. Montandon det. 1903, [syntypes] . São Paulo — 2 m [with eggs on dorsum] ( DEES): Piracicaba , VIII.1974, ([?] Achiel and Abílio [?]), S. de T. Piza-Jr. det. as B. amici, J. R. I. Ribeiro det. 1999. ARGENTINA. 1 m ( MACN 39307 ) : Chaco, Fontana, [without date and collector], J. A. de Carlo det. as B. horvathi, J. R. I. Ribeiro det. 1999 .

Distribution.— BRAZIL: Espírito Santo ( De Carlo 1938), Rio de Janeiro ( Ribeiro 2005), Santa Catarina ( De Carlo 1938), São Paulo ( Ribeiro 2005). ARGENTINA: Chaco (new record).

Description.—Measurements (m / f). Total length (from apex of head to apex of hemelytra at rest) 14.4– 16.8 / 18.6; largest width of body 6.6–7.8 / 8.5; median length of pronotum 2.60–2.80 / 3.04; greatest pronotal width 5.28–5.76 / 6.16.

General coloration dark brown.

Body elliptical. Lengths of anteoculus and interoculus equal; length of rostral segment I 0.87–0.93 times length of segment II; anterior frontogenal suture shorter than posterior frontogenal suture; clypeus reaching ocular line; vertex without longitudinal median carina; posterior interocular width1.53–1.74 times length of anteoculus, and 1.61–2.00 times width of eye; eyes rounded, weakly globular. Pronotum without longitudinal median carina, folded on its median anterior portion; greatest pronotal width 2.03–2.09 times its length; scutellum reaching or not reaching nodal line (0–0.40 mm), without longitudinal median carina; prosternal keel poorly prominent, anteriorly projected, rounded at apex ( Fig. 11J ). Pilosity not extending along genital operculum, covering about half of connexivum.

Male genitalia ( Fig. 11L–N ).—Dorsal arms divergent, rounded at apex in dorsal view; ventral diverticulum circular, without dorsal caudal protuberance in dorsal and lateral views, but ventrally dilated in lateral and ventral views (VED); ventral diverticulum slightly cleft apically, without ventroapical protuberance in lateral and ventral views; caudal lateral margins of ventral diverticulum convex, not sinuous in ventral view; ventral diverticulum as wide as long in ventral view.

Variation.—I have seen a specimen from State of Rio de Janeiro measuring 18.6 mm with prosternal keel weakly anteriorly projected ( Fig. 11K ).

Comparative notes.— De Carlo (1938) and Schnack (1973, 1976) reported B. sanctulum specimens with the greatest pronotal width less than twice its length. Nevertheless, the conspicuous shorter pronotum as an attribute of B. sanctulum , as reported by Nieser and Melo (1997) and repeated by this study, is clearly evident.

Belostoma sanctulum resembles B. candidulum in having the dorsal arms of ventral diverticulum divergent, 2.5 times longer than the anterior portion of phallus ( Estévez 1996) but may be separated by the shape of ventral diverticulum, which is slightly cleft apically in ventral view ( Fig. 11M ). In B. candidulum , by contrast, the ventral diverticulum is rounded apically.

Figures

FIGURE 11. Belostoma candidulum Montandon, 1903, B. horvathi Montandon, 1903, and B. sanctulum Montandon, 1903. B. candidulum. 11A, Prosternal keel (lateral view): specimen from State of São Paulo (SEMC). Scale: 0.50 mm. 11B–D, Phallus: specimen from Chaco, Argentina (MACN 39307). Scale: 1.00 mm. B. horvathi. 11E–F, Prosternal keel (lateral view): 11E, Specimen from State of Minas Gerais (DPIC 1641). 11F, Specimen from State of Minas Gerais (DPIC 1218). 11G–I, Phallus: specimen from State of São Paulo (SEMC 1063). Scale bar: 1.00 mm. B. sanctulum. 11J– K, Prosternal keel (lateral view): 11J, Specimen from State of Espírito Santo (ISNB). 11K, Specimen from State of Rio de Janeiro (DZRJ 17). Scale: 0.50 mm. 11L–N, Phallus: specimen from State of Espírito Santo (ISNB). Scale: 1.00 mm. 11B, 11G and 11L, Dorsal views. 11C, 11H, and 11M, Ventral views. 11D, 11I and 11N, Lateral views. (VED) ventral dilatation.

FIGURE 20. Dorsal habitus. 20A, Belostoma noualhieri Montandon, 1903: specimen from State of Rio Grande do Sul (MNHN, holotype). 20B, B. plebejum (Stål, 1860): specimen from State of Espírito Santo (MNRJ 170). 20C, B. ribeiroi De Carlo, 1933: specimen from State of Rio de Janeiro (MACN 3680). 20D, B. sanctulum Montandon, 1903: specimen from State of Espírito Santo (HNHM). Scale bar: 5.00 mm.

FIGURE 24. Geographic distribution map of Belostoma species in southeastern Brazil. 24A, = B. foveolatum, = B. horvathi. 24B, = B. plebejum, = B. ribeiroi, = B. sanctulum.