Xystosomus sculpticollis Bates, 1871

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

6. Xystosomus sculpticollis Bates

FIGURES 11 , 28 , 69

Xystosomus sculpticollis Bates, 1871b:266 . [Lectotype, male,

MHNP, here selected. Type-locality: Ega (Teffe) , Brazil.]

DESCRIPTION.—Form: As in X. strigosus, but easily distinguished from that species and all other species of the group by the longitudinal carinae of the pronotal disc.

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

Head: Narrow between eyes; frontal furrows moderately impressed with sharp carinae lateral to them near eye margin; eyes large and prominent.

Pronotum ( Figure 11 ): Quadrate (W/L, x 1.46; range, 1.39-1.58; 3 specimens), only slightly wider than head across eyes; disc with six longitudinal carinae, each separated from the other by deep sulci; hind angles about 90°, sides anterior to angles straight to about middle; side margins broadly explanate in basal half, narrowly explanate in apical half.

Elytra: Striae 1-8 of each elytron well impressed and punctate, entire though less impressed at apex; punctures large and well impressed, more so laterally, each contiguous with the next by a shallowly impressed stria, at least in basal half; recurrent groove doubled back into a hook, deeply impressed; chaetotaxy as in X. gruti ; plica well developed externally, short.

Microsculpture: As in X. gruti .

Secondary sexual characters: Male genitalia characteristic of the species group (Figure 28). Female genitalia characteristic of the species group.

Size: Three specimens: length, 3.3-3.6 mm; width, 1.6-1.8 mm.

NATURAL HISTORY.— Unknown, except that the specimen from Teffe was collected in the "1 st quarter of 1879." No teneral specimens seen.

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

SOUTH AMERICA: BRAZIL: Amazonas Province: Sao Paulo d'Olivenga (MHNP); Teffe ( Ega ) (MHNP).

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.