Belostoma plebejum ( Stål, 1860 )

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 : 46-48

Belostoma plebejum ( Stål, 1860)

( Figs 12F–O ; 20B ; 24B )

Zaitha plebeja Stål, 1860: 83 .

Zaitha maculosa Dufour, 1863: 389 .

Zaitha limbata Dufour, 1863: 390 .

Zaitha adusta Dufour, 1863: 390 .

Zaitha difficilis Dufour, 1863: 391 .

Zaitha micantula: Dufour 1863 [probably]: 391 (not Stål).

Belostoma plebejum: Kirkaldy & Torre-Bueno 1909 [probably in part]: 192.

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

Types.—According to Estévez (1996: 78), B. plebejum was described based on a male holotype (Rio de Janeiro) deposited in NHRS [labelled “ Rio Jan. ”] [not examined] .

Material examined.— BRAZIL. *1 f (INPA 0021045): “CENAT, R. Humb. (n. 0125)” [?], 26.IX.1975, (L. P. Alb. [?] and J. B. Moraes), J. R. I. Ribeiro det. 1999. Bahia — * 22 m / 14 f (AMNH): Encruzilhada [960 m], XI.1972, (M. Alvarenga), J. R. I. Ribeiro det. 1999. Espírito Santo — * 1 m (MNRJ 170): Linhares, Parque Sooretama, “col. 1954”, X.1959, (D. Zajclw), J. R. I. Ribeiro det. 1999. Mato Grosso — 2 m (AMNH): Barra do Tapirapé, 26.VII.1963, (B. Malkin), J. R. I. Ribeiro det. 1999. 2 m (AMNH): “SINOP-Sociedade Imobiliária do Noroeste do Paraná ”, X.1976, (M. Alvarenga), J. R. I. Ribeiro det. 1999. * 3 m (AMNH): “SINOP”, [12 º 31’ S / 55 º 37’ W], X.1974, (M. Alvarenga), J. R. I. Ribeiro det. 1999. 1 f (AMNH): same. Minas Gerais — * 5 m / 3 f (AMNH): Pirapora, XI.1975, (M. Alvarenga), J. R. I. Ribeiro det. 1999. Pará— *2 f (AMNH): Jacareacanga, XII.1968, (M. Alvarenga), J. R. I. Ribeiro det. 1999. São Paulo — * 1 m (MZSP): Itu, “Fazenda Pau d’Alho”, 22.XI.1969, ([?] Martins), J. R. I. Ribeiro det. 1999. 3 m / 7 f (ESALQ): Piracicaba, VIII.1974, ([?] Achiel and Abílio [?]), S. de T. Piza-Jr. det. as B. amici, J. R. I. Ribeiro det. 1999, B. amici paratypes. 1 m (MZSP): Ribeirão Preto, “Faz. Iracema”, 11.XII.1953, (M. P. Barretto) [M. P. Barretto, 1969 collection], J. R. I. Ribeiro det. 1999. 3 m (MZSP): same, “Fac. Medicina”, XII.1954, (M. P. Barretto) [M. P. Barretto, 1969 collection], J. R. I. Ribeiro det. 1999. *1 f (MZSP): same. 1999. PARAGUAY. 1 f (MZSP): Puerto Casado, XII.1958, (A. Martinez), J. R. I. Ribeiro det. 1999.

Distribution.— ARGENTINA ( Kirkaldy & Torre-Bueno 1909): Buenos Aires ( De Carlo 1930), Concordia [as “ Entre Ríos –Concordia”] ( De Carlo 1930), Corrientes ( De Carlo 1930), Entre Ríos ( De Carlo 1930), Misiones ( De Carlo 1930), Santa Fe ( Estévez 1996), Tucumán ( Estévez 1996). BRAZIL ( Dufour 1863): Bahia ( Ribeiro 2005), Espírito Santo ( Ribeiro 2005), Goiás ( Menke & Lauck 1962), Mato Grosso ( Ribeiro 2005), Minas Gerais ( Nieser & Melo 1997), Pará ( Ribeiro 2005), Rio de Janeiro ( Stål 1860), Santa Catarina ( Estévez 1996), São Paulo ( Estévez 1996). PARAGUAY ( Menke & Lauck 1962): Alvobena ( Estévez 1996), Guairá [as “Villarica” sic (= Villa Rica)] ( Estévez 1996). PERU: Marañón River ( Estévez 1996), Quincemil ( Estévez 1996). URUGUAY: Lavalleja ( Ruffinelli & Pirán 1959), Tacuarembó ( Estévez 1996). VENEZUELA ( Mayr 1871).

Description.—Measurements (m / f). Total length (from apex of head to apex of hemelytra at rest) 13.6– 16.0 / 13.7–16.9; largest width of body 6.0–8.0 / 6.4–7.9; median length of pronotum 2.33–2.75 / 2.25–2.75; greatest pronotal width 4.65–5.50 / 4.50–5.50.

General coloration brown.

Body elliptical. Length of anteoculus 0.79–0.95 times length of interoculus; length of rostral segment I 0.78–0.94 times length of segment II; anterior frontogenal suture equal to or longer than posterior frontogenal suture; clypeus reaching ocular line; vertex without longitudinal median carina; posterior interocular width 1.82–2.13 times length of anteoculus, and 1.65–1.94 times width of eye; eyes rounded. Pronotum without longitudinal median carina; greatest pronotal width twice its length; scutellum not reaching nodal line (0.10–0.45 mm), without longitudinal median carina; prosternal keel not prominent, rounded, obtuse at apex ( Fig. 12F ). Pilosity not extending along genital operculum, covering about one-third of connexivum.

Male genitalia ( Fig. 12G–I ).—Dorsal arms slightly divergent, not covering the external margin of ventral diverticulum, rounded at apex in dorsal view; ventral diverticulum strongly curved, without evident median depression caudally, without dorsal caudal protuberance in dorsal and lateral views, and without ventroapical protuberance in lateral and ventral views; caudal lateral margins of ventral diverticulum convex, not sinuous in ventral view; width of ventral diverticulum about 1.3 times its length in ventral view.

Variation.—I have seen specimens from the states of Minas Gerais and Rio de Janeiro which show ventral diverticulum of phallus poorly curved, with caudal lateral margins slightly sinuous in ventral view ( Fig. 12J– L ). Another specimen has the dorsal arms short and acute at apex in dorsal view ( Fig. 12M–O ).

Notes on biology.—According to Nieser and Melo (1997), B. plebejum is a common species, being found in various ponds and lakes.

Comparative notes.— Dufour (1863) described several species with the same general facies corresponding to my understanding of “ B. plebejum . ” Interestingly, these species were differentiated on the basis of differences in body length. As reported in Pereira (1992) and Pereira and Melo (1998), B. plebejum specimens can have different body length when exposed to several kinds of prey. According to Nieser and Melo (1997), B. plebejum can attain a total length of 13.5–15.0 mm. Estévez (1996) and Mayr (1871), on the other hand, reported specimens of B. plebejum up to 18.0 mm. long.

The prosternal keels of the specimens studied here are identical and agree with B. plebeum drawings by Estévez (1996). However, Estévez (1996) reported some specimens with a more prominent prosternal keel. According to this author, B. plebejum resembles B. micantulum in having the ventral diverticulum of phallus strongly curved but may be separated by the shape of prosternal keel and the dorsal arms, which do not cover the external margin of ventral diverticulum. In B. micantulum , by contrast, the dorsal arms cover the external margin of ventral diverticulum.

Figures

FIGURE 12. Belostoma micantulum (Stål, 1860) and B. plebejum (Stål, 1860). B. micantulum. 12A–B, Prosternal keel (lateral view): 12A, Specimen from Suriname (MACN); 12B, Specimen from Corrientes, Argentina (MACN 50331). Scale: 0.50 mm. 12C–E, Phallus: specimen from State of Pará (AMNH). Scale: 1.00 mm. B. plebejum. 12F, Prosternal keel (lateral view): specimen from State of Bahia (AMNH). 12G–O, Phallus: 12G–I, Specimen from State of Bahia (AMNH). 12J–L, Specimen from State of Minas Gerais (AMNH). 12M–O, Specimen from State of Rio de Janeiro (DZRJ 22). Scale bar: 1.00 mm. 12C, 12G, 12J, and 12M, Dorsal views. 12D, 12H, 12K, and 12N, Ventral views. 12E, 12I, 12L, and 12O, Lateral views. (MED) median depression.

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.