Xystosomus iris, 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 : 11

5. Xystosomus iris , new species

FIGURES 10 , 27, 69

TYPE-LOCALITY.— Monson Valley, Tingo Maria , Peru.

TYPE-SPECIMENS.—The holotype male and allotype are in CAS . Both were collected by Schlinger and Ross in 1954. Four paratypes from Bolivia: MHNP, 2; USNM, 2.

DESCRIPTION.—Form: As in X. strigosus, except pronotum much narrower. Narrowest species in the group in relation to head width. Easily distinguished from all species of the group by the doubled back recurrent groove which forms a large loop.

Color: Head and body rufopiceous; pronotum and elytra with slight metallic green luster; elytra also strongly iridescent; appendages testaceous; antennae slightly infuscated apically.

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

Pronotum ( Figure 10 ): Quadrate (W/L, x 1.46; range, 1.44-1.57; 6 specimens), only slightly wider than head across eyes; hind angles about 90°, side

margins anterior to angles slightly sinuate; side margins narrowly explanate basally, beaded anteriorly.

Elytra: Striae 1-8 of each elytron well impressed and punctulate; punctures moderately large and separated by about twice their own diameter; recurrent groove doubled back into a deeply impressed elliptical loop; humeral projection well developed, sharply acute (oblique view); chaetotaxy as in X. gruti ; plica short, evident externally.

Microsculpture: As in X. gruti .

Secondary sexual characters: Male genitalia (Figure 27) and female genitalia characteristic of the species group.

Size: Six specimens: length, 3.0-3.6 mm; width, 1.4-1.7 mm.

NATURAL HISTORY.— Unknown, except adults collected in March (Bolivia) and October (Peru). No teneral specimens seen.

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

SOUTH AMERICA: BOLIVIA: Cochabamba (MHNP); Ca- chuela Esperanza (USNM). PERU: Monson Valley, Tingo Maria ( CAS ).

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.