Belostoma stollii ( Amyot & Serville, 1843 )

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 : 48-50

Belostoma stollii ( Amyot & Serville, 1843)

( Figs 13 ; 21A ; 25 )

Zaitha stollii Amyot & Serville (1843) [designation of type-species of Zaitha ]: 430.

Zaitha stolli Mayr, 1871: 406 .

Belostoma stolli Montandon apud Lauck (1963): 240.

Belostoma stollii: Kirkaldy & Torre-Bueno 1909: 192 .

Belostoma brasiliensis De Carlo, 1950: 529 . Syn. n.

Belostoma planum Lauck, 1963: 47 , (Fig. 58), (Fig. 64). Syn. n.

Belostoma stolii Nieser & Melo, 1997: 61 .

Types.— Belostoma stollii was described from specimens [unknown locality] which have since been lost, and thus Lauck (1963) proposed a male neotype ( Rivière de Kourou , Pariacabo, French Guyana) deposited in USNM [not examined] .

Material examined.— BOLIVIA. *1 f ( MACN 53946): Santa Cruz, Nueva Moka, III.1955, ([?] Martinez), J. A. de Carlo det. as B. brasiliensis, J. R. I. Ribeiro det. 1999. BRAZIL. Amazonas— *1 f ( AMNH): Igarapé, Belém, “near to Solimões River al. [?] 70 km E Letícia”, V.1970, (B. Malkin), J. R. I. Ribeiro det. 1999. * 1 m / 3 f ( SEMC 9): Amazonas River, “Lur” [?], Tapaiuna lake region, I–IV.1936, (A. M. Olalla), D. W. Craik det. as B. decarloi, D. R. Lauck det. 1959, B. decarloi paratype. Pará— *1 f ( MNRJ 107): Cachimbo, VI.1955, (J. A. Araújo), J. A. de Carlo det. as B. brasiliensis, J. R. I. Ribeiro det. 1999. Rio de Janeiro — * 1 m (DZRJ-a 465): Magé, 14.II.1988, [without collector], J. R. I. Ribeiro det. 1998. * 1 m (DZRJ-a 466): same, Citrolândia, [without date], (H. W. Tavares), J. R. I. Ribeiro det. 1998. GUYANA. *1 f ( SEMC): Supuruni Creek, 23.VIII.1937, (S. Harris), D. W. Craik det. as B. decarloi, D. R. Lauck det. 1959, B. decarloi paratype. FRENCH GUYANA. *1 f ( MNHN): Cayenne, [without date], (“Noualhieri, 1899”), A. L. Montandon det. 1899, “Lethierry collection”. PERU. 1 m ( SEMC 398): Huanuco, “Loc. Shapajila 630 m. a.s.l. 11 km, NE Tingo Moria”, 1939, (F. Woytkowski), D. W. Craik det. as B. stollii, D. R. Lauck det. 1959 as B. planum, J. R. I. Ribeiro det. 1999, B. planum holotype. SURINAM. * 1 m ( MACN): Saracreek, “near to Locus, Museum Leiden” [?], 13. V.1964, (P. Leentvaar), J. A. de Carlo det. as B. brasiliensis, J. R. I. Ribeiro det. 1999.

Distribution.— BOLIVIA: Santa Cruz ( Ribeiro 2000). BRAZIL ( De Carlo 1938): Amazonas ( Lauck 1963), Mato Grosso ( Lauck 1963), Minas Gerais ( Nieser & Melo 1997), Pará ( Ribeiro 2000), Rio de Janeiro ( Ribeiro 2000). FRENCH GUYANA: Cayenne (new record), Pariacabo ( Lauck 1963). GUYANAS [?] ( De Carlo 1938). GUYANA: Supuruni Creek ( Nieser 1975). PERU ( Ribeiro 2005): Huanuco. SURINAM ( Lauck 1963): Brokopondo ( Nieser 1975), Marowijne ( Nieser 1975), Nickerie ( Nieser 1975), Saracreek (new record). VENEZUELA: Território do Amazonas ( Lauck 1963).

Description.—Measurements (m / f). Total length (from apex of head to apex of hemelytra at rest) 31.7– 37.5 / 34.8–39.4; largest width of body 15.0–18.2 / 17.6–19.3; median length of pronotum 5.04–6.24 / 5.92– 6.40; greatest pronotal width 9.52–11.84 / 10.80–12.40.

General coloration dark brown. Protibia with whitish annulation.

Body elliptical and flattened. Length of anteoculus 1.15–1.59 times length of interoculus; length of rostral segment I 0.74–1.10 times length of segment II; anterior frontogenal suture usually longer than posterior fron- togenal suture; clypeus reaching or not reaching ocular line (0–0.24 mm); vertex with evident longitudinal median carina; posterior interocular width 1.31–1.70 times length of anteoculus, and 1.63–1.92 times width of eye; eyes rounded. Pronotum with dense covering of short scalelike hairs, and with longitudinal median carina ( Fig. 21A , LOC); greatest pronotal width 1.82–2.03 times its length; scutellum not reaching nodal line (0.16– 0.96 mm), with longitudinal median carina and two lateral pilose ones; prosternal keel not prominent, somewhat rounded, anteriorly projected at apex ( Fig. 13A ). Pilosity not extending along genital operculum, covering about half of connexivum.

Male genitalia ( Fig. 13C–E ).—Dorsal arms slightly short and narrow with sinuosity, rounded at apex in dorsal view; ventral diverticulum without dorsal caudal protuberance in dorsal and lateral views, and with poorly developed ventroapical protuberance in lateral and ventral views; caudal lateral margins of ventral diverticulum convex, not sinuous in ventral view; width and length of ventral diverticulum equal in ventral view.

Variation.—A specimen collected in the State of Amazonas, has a prosternal keel greatly rounded, not anteriorly projecting ( Fig. 13B ). Specimens collected in the State of Rio de Janeiro, and in Saracreek, Suriname, show slight phallic variation. The dorsal arms in the specimens from Rio de Janeiro are slightly larger and shorter, whereas in the specimens from Surinam the dorsal arms are longer and more sinuous. In addition, in these forms show caudal lateral margins of ventral diverticulum are sinuous in ventral view ( Fig. 13F–K ).

Comparative notes.—This a very distinctive species. The pronounced carina on vertex and the posterior portion of pronotum, and pronotum with a dense covering of short scalelike hairs are, in combination, diagnostic. Nevertheless, there is variation in rostral length in this species. Forms with the rostral segments I and II subequal in length were reported by De Carlo (1938), Lauck (1963), and Mayr (1871); whereas specimens with the variability found here were reported also by Nieser (1975).

De Carlo (1950) described B. brasiliensis with the same general facies corresponding to my and his understanding of B. stollii . In addition, De Carlo’s B. brasiliensis specimens key to B. stollii in Nieser and Melo’s (1997: 61) key, and are therefore here determined to be B. stollii . In short, all the structural features cited by De Carlo (1950) for B. brasiliensis are slight and well within the range of variability found intraspecifically in B. stollii . I therefore synonymize B. brasiliensis with B. stollii .

According to Lauck (1963), a Peruvian species, B. planum , differs from B. stollii because its pronotum lacks the scalelike hairs; however, these fall off if handled or not correctly preserved ( Nieser & Melo 1997). Nevertheless, the phallus of the B. stollii specimens from Rio de Janeiro State are the same as those from B. planum as illustrated by Lauck (1963). I therefore synonymize also B. planum with B. stollii .

The phalluses of the specimens from Rio de Janeiro and Surinam ( Fig. 13C–H ) and those studied by Nieser (1975) and Lauck (1963), indicate a clinal variation in some phallus characters, as the specimens occurring at other localities do show either incremental or continuous change with latitude. For example, forms with narrower dorsal arms are found in northern South America, whereas specimens with larger dorsal arms tend to be found at the southern extreme of the species’ range. In sum, it would appear that this is a particularly variable species, and that phallic variability clearly shows a geographic pattern.

Figures

FIGURE 13. Belostoma stollii (Amyot & Serville, 1843). 13A–B, Prosternal keel (lateral view): 13A, Specimen from State of Rio de Janeiro (DZRJ-a 465), 13B, Specimen from State of Amazonas (SEMC). 13C–K, Phallus: 13C–E, Specimen from State of Rio de Janeiro (DZRJ-a 465). 13F–H, Specimen from Saracreek, Suriname (MACN). 13I–K, Specimen from State of Rio de Janeiro (DZRJ-a 466). 13C, 13F and 13I, Dorsal views. 13D, 13G, and 13J, Ventral views. 13E, 13H, and 13K, Lateral views. Scale bar: 1.00 mm.

FIGURE 21. Dorsal habitus. 21A, Belostoma stollii (Amyot & Serville, 1843): specimen from State of Amazonas (SEMC 9). 21B, B. testaceopallidum Latreille, 1807: specimen from State of Rio de Janeiro (MACN 3680). Scale bar: 5.00 mm. (LOC) longitudinal carina.

FIGURE 25. Geographic distribution map of Belostoma species in southeastern Brazil. = B. stollii, = B. testaceopallidum.