Oebalus ypsilongriseus ( De Geer, 1773 )

Barros, Lurdiana D., Paim, Marcelo R., Krein, Verônica, Carabajal, Victor, Brandão, Marcela N., Bernardes, Paula De O. & Lindner, Mariana F., 2021, Illustrated guide to Pentatominae (Hemiptera: Pentatomidae) species associated with the four main grain crops in Rio Grande do Sul state, Brazil, Zootaxa 4958 (1), pp. 430-478 : 464-465

Oebalus ypsilongriseus ( De Geer, 1773)

( Figs 98–99 )

Cimex ypsilon-griseus De Geer, 1773: 333 .

Oebalus ypsilonoides Berg, 1878: 302 .

Solubea ypsilonoides: Kirkaldy, 1909: 62 .

Solubea ypsilionides [sic]: Pennington, 1920: 8.

Solubea ypsilongriseus: Sailer, 1944: 116 .

Solubea grisescens Sailer, 1944: 118 .

Oebalus ypsilongriseus: Quintanilla et al., 1968: 33 .

Material studied. Guaíba: 1♂, 24.II.1988, M. C. Del Vecchio & J. A. M, Fernandes leg., “Sobre gramíneas vizinhas à lavouras de Soja”, J. Grazia det. ( UFRG) ; 1♀, 15.III.1974, E. Heinrichs leg., “Soja” ( UFRG) ; 1♀, 24.VIII.1988, “vizinho à lavoura de Soja”, M. C. Del Vecchio & J. A. M. Fernandes, J. Grazia det. 19?? ( UFRG) .

Diagnostic features. Body elongate and slim, dorsal surface castaneous with two small pale yellow spots on pronotum ( Fig. 98 ). Mandibular plates subequal to clypeus and rounded apically. Pronotum sloping, anterolateral margins of pronotum concave. Humeral angles with variable development, from weakly produced to forming an acute spine, directed anterolaterally, black. Scutellum with three yellow callosities, of variable size ( Fig. 98 ). Body length: 8.00–10.00 mm.

Recorded host plants. Oat ( Campos et al. 2009); rice, soybean ( Grazia 1977; Link & Grazia 1987; Del Vecchio & Grazia 1992) and wheat ( Link & Grazia 1987; Campos et al. 2009). This species may also use sorghum (Sorghum bicolor) and Echinochloa spp., Paspalum spp., Brachiaria spp., Digitaria spp. grasses as alternative hosts ( Ferreira et al. 2001; Hickel et al. 2016).

Distribution in Rio Grande do Sul. Eldorado do Sul, Guaíba, Santa Maria and São Gabriel ( Fig. 99 ).

Comments. This species is similar to O. poecilus , being differentiated by having yellow callosities only on scutellum (while O. poecilus also has spots on pronotum and corium). The humeral angles spines, when strongly developed, are also different: they are directed anterolaterally in O. ypsilongriseus , but directed laterally in O. poecilus . Both species have seasonal morphological dimorphism, with active adults being more colorful and with well-developed spines, and overwintering adults mostly castaneous with shorter and rounded lateral spines ( Albuquerque 1993) (see Garbelotto & Campos 2014).

Figures

FIGURES 98–99. Oebalus ypsilongriseus. 98: Dorsal view, scale bar = 1.0 mm. 99: Distribution within Rio Grande do Sul.