Xystosomus anterocostis, 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 : 14

9. Xystosomus anterocostis , new species

FIGURES 14 , 31 , 69

TYPE-LOCALITY. — Hamburg Farm at Reventazón , Costa Rica.

TYPE-SPECIMENS.—The holotype male, allotype, and one female paratype are in USNM. All were collected by Nevermann.

DESCRIPTION.—Form: As in X. gruti , except elytra slightly more convex. Easily distinguished among the "smooth elytra-convex interval" group of species by the sinuate sides of the pronotum.

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

Head: Broad Letween eyes; frontal furrows deeply impressed, almost sulcate; eyes large and prominent.

Pronotum ( Figure 14 ): Transverse (W/ L, x 1.63; range, 1.53-1.75; 3 specimens); otherwise as in X. gruti , except side margins sinuate at basal third.

Elytra: Striae 5-8 well impressed and punctulate; intervals convex, at least in basal third; disc with four rows of faintly impressed punctulae, each well separated from the other, intervals flat; side margins broadly explanate; humeral projection well developed, blunt; chaetotaxy as in X. gruti; plica small, evident externally.

Microsculpture: As in X. gruti .

Secondary sexual characters: Male genitalia ( Figure 31 ) and female genitalia characteristic ol the species group.

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

NATURAL HISTORY.—F. Nevermann collected two specimens on "wilted foliage of Quararibae turbinata, October" ( Bombacaceae ) and one specimen "on dry leaves, September." No teneral specimens seen.

LOCALITY RECORDS ( Figure 69 ).—I have seen three specimens from the following locality: CENTRAL AMERICA: COSTA RICA: Hamburg Farm at Reventazon (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.

FIGURES 31-35.—Male genitalia, left lateral aspect, of five species of the gruti group: 31, Xysto- somus anterocostis, Hamburg Farm, Costa Rica; 32, X. sublaevis, Volcan de Chiriqui, Panama; 33, X. sulcicostis, Volcan de Chiriqui, Panama; 34, X. seriatus, Nova Teutonia, Brazil; 35, X. ovatulus, Nova Friburgo, Brazil.