Xystosomus batesi, 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 : 19

13. Xystosomus batesi , new species

FIGURES 18 , 69

TYPE-LOCALITY.— Petrópolis , Brazil.

TYPE-SPECIMEN.—The unique holotype female, collected by Sahlberg, is in MHNP.

DESCRIPTION.—Form: As in X. gruti , except shorter. Easily distinguished by the absence of elytral microsculpture and the short frontal furrows.

Color: Head and body piceous; pronotum and head shiny; appendages tetaceous or partly infuscated.

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

Pronotum ( Figure 18 ).— Transverse (W /L, 1.61; 1 specimen); hind angles slightly obtuse; sides anterior to angles slightly arcuate; otherwise as in X. gruti .

Elytra: Each elytron with seven rows of serial punctulae; stria 8 well impressed, coarsely punctate in basal half; punctulae of disc smaller and less impressed than those laterally, all rows effaced before apex; intervals flat, except interval 8 which is slightly convex; side margins broadly explanate; humeral tooth well developed, rounded; chaetotaxy as in X. gruti ; plica small, evident externally.

Microsculpture: Head and pronotum as in X. gruti , except faintly impressed on pronotum; effaced from elytra.

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

Size: One specimen: length, 3.4 mm; width, 1.7 mm.

NATURAL HISTORY.— Unknown.

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