Xystosomus ovatulus Bates, 1863

Erwin, Terry L., 1973, Studies of the subtribe Tachyina (Coleoptera: Carabidae: Bembidiini), Part I: A revision of the Neotropical genus Xystosomus Schaum, Smithsonian Contributions to Zoology 140, pp. 1-39 : 20

15. Xystosomus ovatulus Bates

FIGURES 20 , 22 g , 35 , 69

Xystosomus ovatulus Bates, 1871a: 247 . [Lectotype, female, MHNP, here selected. Type-locality: Rio de Janeiro, Bra- dl.]

DESCRIPTION.—Form: As in X. gruti , except elytra more convex. Easily distinguished from all species of the group by the punctate elytra along with the coarse, meshed microsculpture which produces

a matte-like finish on the elytra.

Color: Head and body piceous; forebody slightly darker than elytra especially toward apex of elytra; pronotum and elytra slightly iridescent; appendages testaceous.

Head: Narrow between eyes; frontal furrows deeply impressed, extended to just beyond mideye level; eyes large and prominent.

Pronotum ( Figure 20 ): Transverse (W / L, x 1.49; range, 1.38-1.52; 6 specimens); hind angles acute, denticulate, sides anterior to angles straight; side margins narrowly explanate to anterior lateral setigerous pores; otherwise as in X. gruti .

Elytra: Each elytron with eight rows of serial punctulae impressed at least in basal two-thirds; punctulae separated by their own diameter or more; extreme apex of row 2 sulcate; otherwise as in X.

gruti.

Microsculpture: As in X. gruti except lines joined to form meshes on elytra ( Figure 22 g).

Secondary sexual characters: Male genitalia ( Figure 35) and female genitalia characteristic of the species group.

Size: Six specimens: length, 3.4-4.0 mm; width, 1.6 -1.8 mm.

NATURAL HISTORY.— Unknown, except adults

were collected in February and the " second quarter " of the year.

LOCALITY RECORDS ( Figure 69 ).—I have seen seven specimens from the following localities:

SOUTH AMERICA: BRAZIL: Minas Gerais Province: Rio Piracicaba (MHNP); Caraca (MHNP). Rio de Janeiro Province: Nova Friburgo (MHNP).

Figures

FIGURE 22.—Scanning electron micrographs (X125O) of dorsal microsculpture. Xystosomus gruti: a, frons; b, pronotal disc; c, disc of left elytron; note serial puncture. Xystosomus turgidus: d, frons; e, pronotal disc; /, disc of left elytron. Xystosomus ovatulus: g, disc of left elytron; note serial puncture.

FIGURE 69.—Approximate range of the gruti group.

FIGURES 7-21.—Pronotum, dorsal aspect: 7, Xystosomus ampliatus, female, Hamburg Farm, Costa Rica; 8, X. nigripalpis, female, Barro Colorado Island, Panama; 9, X. strigosus, female, Rio Parahyba, Brazil; 10, X. iris, female, Cochabamba, Bolivia; 11, X. sculpticollis, female, Teffe, Brazil; 12, X. negrei, male, Rancho Grande, Venezuela; 13, X. aetholius, female, Cochabamba, Bolivia; 14, X. anterocostis, Hamburg Farm, Costa Rica; 15, X. sublaevis, male, Rio Banano, Costa Rica; 16, X. sulcicostis, female, Volcan de Chiriqu!, Panama; 17, X. apicisulcatus, female, Minas, Brazil; 18, X. batesi, female, Petr6polis, Brazil; 19, X. seriatus, female, Nova Teutonia, Brazil; 20, X. ovatulus, female, Caraca, Brazil; 21, X. grossipunctatus, female, Caraca, Brazil.

FIGURES 31-35.—Male genitalia, left lateral aspect, of five species of the gruti group: 31, Xysto- somus anterocostis, Hamburg Farm, Costa Rica; 32, X. sublaevis, Volcan de Chiriqui, Panama; 33, X. sulcicostis, Volcan de Chiriqui, Panama; 34, X. seriatus, Nova Teutonia, Brazil; 35, X. ovatulus, Nova Friburgo, Brazil.