Xystosomus apicisulcatus, Erwin, 1973

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 : 18-19

12. Xystosomus apicisulcatus , new species

FIGURES 17 , 69

TYPE-LOCALITY.— Minas , Brazil.

TYPE-SPECIMEN.—The unique holotype female is in MHNP. It was collected by Squires.

DESCRIPTION.— Form: As in X. gruti . Easily distinguished from all species in the group by the sulcate apex of the sutural stria.

Color: Head and body piceous; pronotum and elytra slightly iridescent; appendages testaceous.

Head: Narrow between eyes; frontal furrows shallowly impressed; eyes very large and prominent.

Pronotum ( Figure 17 ): Transverse (W / L, 1.61; 1 specimen); hind angles obtuse, sides anterior to angles more or less straight; side margins moderately explanate in basal half, beaded anteriorly; otherwise as in X. gruti .

Elytra: Each elytron with seven rows of partially striate serial punctulae; stria 8 deeply impressed, almost sulcate; recurrent groove very deeply sulcate and hooked at apex; apex of sutural and second row of punctulae deeply sulcate; side margins broadly explanate; humeral projection well developed, obtuse; chaetotaxy as in X. gruti ; plica small, evident externally.

Microsculpture: Pronotum with coarsely impressed transverse meshes, nearly isodiametric along anterior margin; otherwise as in X. gruti .

Secondary sexual characters: Male genitalia unknown. Female genitalia characteristic of the species group.

Size: One specimen: length, 3.8 mm; width, 1.6 mm.

NATURAL HISTORY.— Unknown.

LOCALITY RECORDS ( Figure 69 ).— I have seen only the unique type from Minas, Brazil.

Figures

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.