Puelchesia Ocampo and Smith

Ocampo, Federico C. & Smith, Andrew B. T., 2006, Puelchesia gracilis, a new genus and species of Pachydemini endemic to the Monte biogeographic province in Argentina (Coleoptera: Scarabaeidae: Melolonthinae), Zootaxa 1349, pp. 53-62 : 55-56

Puelchesia Ocampo and Smith , gen. nov.

( Figs. 1–13 )

Type species. Puelchesia gracilis Ocampo and Smith , here designated.

Description. Head ( Figs. 1–4 ): Eye canthus absent ( Figs. 3, 4 ). Clypeus broadly rounded, margin reflexed. Labrum reduced, conical, not visible beyond clypeal margin. Labium reduced, labial palpus absent. Antennae with 8 antennomeres, antennal club 3- segmented. Pronotum ( Figs. 1–3 ): Convex, wider than long. Marginal bead present in all margins; anterior margin concave, with membrane; lateral margins slightly angular; posterior margin slightly sinuous. Anterior angles acute; posterior angles broadly rounded. Elytra ( Figs. 1, 2 ): Convex, elongate, subparallel, completely covering dorsal surface of abdomen. Elytra with 9 striae. Ve n te r: 3 ventrites exposed medially, penultimate ventrite broadly membranous on apical margin. Pygidium oblique with respect to body, not recumbent toward metacoxae. Legs ( Figs. 1, 2 , 7–9 ): Protibiae with 3 teeth, protibial spur slightly curved. Meso- and metatibiae with medial transverse carinae. Meso- and metatibial spurs subcontiguous, metatibial spurs both set below tarsal articulation. Metatibial tarsal insertion simple, without notch. Metatarsus 1.7 times longer than metatibia. Pro-, meso-, and metatarsomeres 1–4 subequal in length, tarsomere 5 longer than 1–4 individually; all tarsi with long, apical setae ( Figs. 1, 2 , 7, 8 ). Tarsal claws simple (without teeth, lobes, or bifurcations), symmetrical ( Figs. 1, 2 , 7, 8 ). Male Genitalia ( Figs. 10, 11 ): parameres simple, symmetrical, elongate, gracile,

Classification. This genus is placed in the tribe Pachydemini based on the characters listed below in the Diagnosis section. The tribe Pachydemini includes 116 genera and approximately 530 species worldwide ( Evans 2003; Smith & Evans 2005; Lacroix 2006). They are distributed in all major biogeographic regions except India and Australia. Neotropical Pachydemini are mainly distributed in the Monte, Chacoan, Central Chile, and Patagonian biogeographical provinces. In the Neotropics, the group is represented by 18 genera and approximately 30 species, although several new taxa are in the process of being described by the senior author and Eider Ruiz Manzanos. The classification of this tribe is tenuous ( Evans 1988, San Martin & Martín Piera 2000) and is currently under review by Ocampo and Eider Ruiz-Manzanos. Under the current Melolonthinae classification system, the placement of this genus in Pachydemini is warranted.

Etymology. Puelchesia is a Latinization of the name for the Puelches indigenous people from southern Mendoza. The name is feminine in gender.

Diagnosis. The genus Puelchesia can be distinguished from all other Neotropical Melolonthinae by the following combination of characters: size 5 mm or less; clypeus broadly rounded; labrum reduced, conical, not visible beyond clypeal margin; antennae with 8 antennomeres, antennal club 3-segmented; venter with 3 ventrites exposed medially; pygidium oblique with respect to body, not recumbent toward metacoxae; metatibial spurs subcontiguous, both set below tarsal articulation; metatarsus longer than metatibia; pro-, meso-, and metatarsomeres 1–4 subequal in length, tarsomere 5 1.3 times longer than 1–4 individually; tarsal claws simple (not toothed), symmetrical.

Neotropical Pachydemini were briefly reviewed by Martínez (1975), who also provided a genus-level key to the tribe. Puelchesia will key out to the subgenus Acylochilus (Acylochiloides) Martínez in Martínez’s key but can be separated from this genus by having the metatibia longer than the metafemur (shorter in Acylochilus ); the pygidial apex not recumbent toward the metacoxae; three ventrites exposed (one ventrite is exposed in Acylochilus ); and elongate, gracile parameres (short and thick in Acylochilus ). Due to the small size of Puelchesia , it could also be confused with the genus Longicrura Frey. However , the later genus is known only from Brazil, has 9 antennomeres, and dentate claws.

Figures

FIGURES 1 – 2. Puelchesia gracilis dorsal and lateral view.

FIGURES 3 – 11. Puelchesia gracilis; 3) head and pronotum, dorsal view; 4) head, ventral view; 5) antenna, dorsal view; 6) left hind wing; 7) left mesotibia and tarsus; 8) left metatibia and tarsus; 9) metatibial apex; 10, 11) male genitalia, lateral and dorsal view.

FIGURE 12. The type locality of Puelchesia gracilis.

FIGURE 13. Distribution of Puelchesia gracilis.