Semiardistomis major, Valdés, 2012

Valdes, Pavel, 2012, Notes about morphological features of the Western Hemisphere subtribe Ardistomina, and revision of genus Semiardistomis Kult (Coleoptera, Carabidae, Scaritinae, Clivinini), ZooKeys 210, pp. 19-67 : 37

Semiardistomis major sp. n. Figs 49 57

Holotype.

Male (USNM), glued on pinned point, genitalia attached in microvial, labeled: printed "Peru: Loreto, Cmp. S. Branch, 11 May 90 75°20'W, 05°12'S T. L. Erwin Coll"/ "Running at night on muddy bank of Rio Samiria-Igapó forest soil organic, grasses"/ "ADP 94456".

Paratypes.

8 exemplars (USNM), 2 exemplars (PVCCu) labeled as the holotype.

Etymology.

The specific epithet is a Latin adjective alluding to the large size of the adults.

Diagnosis.

Elytral surface smooth, striae complete, impunctate, 4 setiferous punctures on interval 3, shoulders rounded. Profemur glabrous. Abdominal sternum VII with 5+5 setiferous punctures.

Habitus.

dorsal aspect, as in Fig. 49 .

Measurements and variation.

Variation of measurements (mm) and ratios for Semiardistomis major sp. n. (n=11) are: HL = 0,93-0,97-0,99; PL = 1,50-1,61-1,66; PW = 1,92-1,98-2,02; EL = 4,47-4,71-4,80; EW = 3,13-3,23-3,33; SBL = 6,90-7,28-7,46; PW/EW = 0,61; PW/PL = 1,23; PL/EL = 0,34; EW/EL = 0,69.

Description.

Body piceous with green reflections, mouthparts and antennae testaceous, legs ferrugineous.

Frons, gena, antennal lobes, pronotum, prosternum, proepisternum, elytra, metasternum and abdominal segments smooth.

Anterior marginal setae on pronotal disc closer to posterior setae than to anterior angles. Elytral disc with 5 setae in interval 3. Abdominal sternum VII with setae near base, 2 on each side; distance between inner pair of preapical setae 0.6 times that between inner and outer setae. Profemur glabrous. Ventral surface of protibia with many setae on basal half.

Clypeus with anterior margin concave medially; lateral lobes distinct, behind level of anterior margin. Frontal impressions deep and wide. Supraantennal lobes with median sulci impressed in basal half. Eyes prominent. Antennomere 2 shorter than antennomere 3; antennomeres 4-10 about 1.8 times longer than wide.

Mentum with median carina extended distad slightly beyond anterior margin of lateral lobes; pit organs opened through oval orifices to the mental- submental suture.

Pronotum ovate, lateral border extended to base.

Elytra oblong, humeri square, striae complete in their length, impunctate.

Metathoracic wingsmacropterous.

Genitalia in both sexes as described for the puncticollis species-group.

Geographical distribution

( Fig. 57 ). Known only from the region of Loreto, in Amazonian Peru.

Habitat and activity.

Records from labels suggest that the habitat of Semiardistomis major is typical of most members of the genus, living on loose soil adjacent to fresh water bodies. In this case data indicate a river bank with organic soil. Active at night.

Material examined.

PERU. Loreto. Rio Samiria Cocha Shinguito near lake margin 25 Aug 1991 (USNM, 1).

Figures

Figure 57. Distribution map of members of the puncticollis species-group.

Figures 49 - 50.. 47 Semiardistomis major sp. n. 50 Semiardistomis rugosus (Putzeys). Dorsal aspect. Scale bar 1 mm.