Xystosomus aetholius, 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 : 12-14

8. Xystosomus aetholius , new species

FIGURES 13 , 30 , 69

TYPE-LOCALITY.— Cochabamba, Bolivia.

TYPE-SPECIMENS.—The holotype male and allotype are in MHNP. These and the paratypes were

collected by P. Germain (no date). Paratypes (31): MHNP, 22; USNM, 9.

DESCRIPTION.—Form: As in X. gruti , except elytra slightly more convex. Easily distinguished from all other species of the group by the complete lack of elytral striae.

Color: Head and body rufous, pronotum and elytra slightly iridescent, appendages testaceous.

Head: Broad between eyes; frontal furrows moderately impressed; eyes large and prominent.

Pronotum ( Figure 13 ): Slightly transverse (W/L, x 1.49; range, 1.41-1.60; 33 specimens), otherwise as in X. gruti .

Elytra: Striae absent; side margins broadly explanate; humeral projection small, blunt; chaetotaxy as in X. gruti ; plica small, evident externally.

Microsculpture: As in X. gruti .

Secondary sexual characters: Male genitalia characteristic of the species group (Figure 30). Female genitalia characteristic of the species group.

Size: Thirty-three specimens: length, 3.5-4.8 mm; width, 1.6-2.0 mm.

VARIATION.—The long series of specimens, all from the type, locality, is remarkably homogeneous, except in size and proportions of the pronotum.

NATURAL HISTORY.— Unknown.

LOCALITY RECORDS ( Figure 69 ).— I have seen 33 specimens from the following locality:

SOUTH AMERICA: BOLIVIA: Cochabamba (MHNP, USNM).

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.

FICURES 23-30.—Male genitalia, left lateral aspect of seven species of the gruti group: 23, Xysto- somus gruti, Volcan de Chiriqui, Panama; 24, X. gruti, apex of median lobe, Hamburg Farm, Costa Rica; 25, X. nigripalpis, Barro Colorado Island, Panama; 26, X. strigosus, Rio Parahyba, Brazil; 27, X. iris, Cochabamba, Bolivia; 28, X. sculpticollis, Sao Paulo d'Olivenc,a, Brazil; 29, X. negrei, Rancho Grande, Venezuela; 30, X. aetholius, Cochabamba, Bolivia.