Ateuchus colossus, Moctezuma, Victor, Sanchez-Huerta, Jose Luis & Halffter, Gonzalo, 2018

Moctezuma, Victor, Sanchez-Huerta, Jose Luis & Halffter, Gonzalo, 2018, Two new species of Ateuchus with remarks on ecology, distributions, and evolutionary relationships (Coleoptera, Scarabaeidae, Scarabaeinae), ZooKeys 747, pp. 71-86 : 75-80

Ateuchus colossus sp. n. Figs 6, 7

Type material

(20 ♂♂, 21 ♀♀). Holotype: 1 ♂ labeled "MEXICO, Oaxaca, San Miguel Chimalapa, San Antonio, 14-X-2015, coprotrap, 16°39'39.3"N, 94°13'23.6"W, cloud forest, 1605 m, V. Moctezuma col.". Paratypes: 1 ♂, same data as holotype; 3 ♀♀ same data except " 16°39'40.9"N, 94°13'25.1"W, 1611 m"; 6 ♂♂, 3 ♀♀, same data except " 16°39'41.8"N, 94°13'13.9"W, 1548 m"; 1 ♂ same data except " 16°39'42.5"N, 94°13'15.1"W, 1553 m"; 5 ♂♂, 5 ♀♀, same data except " 16°39'41.2"N, 94°13'15.6"W, 1562 m"; 2 ♂♂, same data except " 16°39'36.5"N, 94°13'35.1"W, 1665 m"; 1 ♀, same data except " 16°39'40.1"N, 94°13'22.4"W, 1599 m"; 1 ♂, 2 ♀♀, same data except “16°39'40.2’’ N, 94°13'21"W, 1595 m"; 1 ♀, same data except “16°39'40.7’’ N, 94°13'19.7"W, 1593 m "; 1 ♂, same data except " 16°39'36.8"N, 94°13'29.8"W, 1636 m"; 2 ♂♂, same data except " 16°39'42.5"N, 94°13'15.1"W, 1553 m"; 1 ♀, same data except " 16°39'37.5"N, 94°13'27.1"W, 1621 m"; 2 ♀♀, same data except " 16°39'41.1"N, 94°13'16.9"W, 1573 m"; 2 ♀♀, labeled "MEXICO, Oaxaca, San Miguel Chimalapa, Benito Juárez, 24-IX-2015, coprotrap, 16°42'38.2"N, 94°6'40.6"W, pine-oak, 1271 m, V. Moctezuma col."; 1 ♀, labeled "MEXICO, Oaxaca, Santa María Chimalapa, López Portillo, 25-IX-2015, coprotrap, 16°40'28.6"N, 94°3'56.6"W, pine forest, 1219 m, V. Moctezuma col.".

Type deposition.

Holotype and 2 ♂♂, 2 ♀♀ paratypes will be deposited in IEXA. Paratypes will be deposited in the following collections: CEMT (2 ♂♂, 2 ♀♀), CMNC (2 ♂♂, 2 ♀♀), CNIN (2 ♂♂, 2 ♀♀), FSCA (2 ♂♂, 2 ♀♀) JLSHC (2 ♂♂, 2 ♀♀), TAMU (2 ♂♂, 2 ♀♀), VMC (rest of paratypes).

Description.

Holotype male, total length 10.7 mm, maximum elytral width 5.6 mm. Body elongate-oval and convex, dorsum and venter glossy black without metallic sheen, clypeal margin dark reddish brown. Clypeal margin slightly V-shaped, with rounded tooth, lateral margin of head arcuate. Clypeal surface with coarse punctures separated by ≈1-2 diameters, frons surface finely punctate with punctures becoming almost unapparent near frons center, well-impressed clypeogenal suture, genae finely punctate. Pronotum smooth but minutely punctate, midline weakly impressed on posterior half of pronotum, anterior pronotal margin complete and well impressed. Ante rior pronotal angles very acute and projecting anteriorly. Center of pronotal posterior margin with a line of coarse and well-impressed punctures. Proepisternum coarsely wrinkled, proepimeron finely wrinkled. Elytral surface smooth, shiny, and minutely punctate. Striae well-impressed, becoming deeply impressed on elytral apex. Well-impressed strial punctures, slightly wider than striae. Interstriae flat. Pygidium strongly convex and finely punctate. Pygidium dark reddish brown with green metallic sheen on apex. Protibia tridentate, apical spur expanded into a slightly irregular oval shape. Mesotibia with two apical spiniform spurs. Metatibia with apical spur large and spiniform. Ventral apical half of profemur finely and scarcely punctate, but punctures becoming coarse along posterior margin of profemur. Ventral surface of meso- and metafemur minutely punctate. Internal sac of the aedeagus with three hook-shaped copulatrix lamellae, two small and one large; three accessory lamellae; raspule not well developed.

Female. Differs from the male by coarsely punctate head, protibia with acute and slender spur that bends apically, last abdominal sternite broader and pygidium less convex.

Variation

(among 30 randomly selected paratypes). Mean total length 9.9 mm (8.9-10.7 mm). Mean elytral with 5.5 mm (5.2-5.9 mm). Type series color is uniform.

Etymology.

From the Latin adjective colossus that derives from the Greek noun κολοσσός (kolossos = gigantic statue), referring to the fact that this is the largest species of the genus Ateuchus in North America known to date.

Distribution.

The type series was collected in the region of Los Chimalapas, in the east of the state of Oaxaca (Fig. 8).

Ecology.

This species inhabits cloud and temperate forests (pine and pine-oak), within the elevational range 1219 to 1665 m a.s.l. This species was collected using pitfall traps baited with human excrements.

Diagnosis.

This species is distinguished from other North American species by its large body size (at 8.9-10.7 mm, it is the largest Ateuchus species in the region), anterior pronotal angles very acute and produced anteriorly, anterior pronotal margin complete, pronotal posterior margin with a line of coarse punctures, and male genitalia with three hook-shaped copulatrix lamellae, three accessory lamellae and ill-developed raspule.

Remarks.

Ateuchus colossus seems to be closely related to A. illaesum (Fig. 4), but they can be distinguished by differences in size ( colossus is larger), the shape of the anterior pronotal angles (very acute and produced anteriorly on colossus ), accessory and copulatrix lamellae (Figs 7, 9).