Pachystethus

Ramírez-Ponce, Andrés & Morón, Miguel Angel, 2012, Revision of the genus Pachystethus Blanchard with description of three new species from Mexico (Coleoptera: Scarabaeidae: Rutelinae: Anomalini), Zootaxa 3394, pp. 1-24 : 4-5

Key to the species of Pachystethus

1. Pronotum strongly convex; with large, deep, ovate punctures. Elytral striae deep, well marked all along entire length of the elytra. Meso-metasternal process with narrow base slightly narrowed towards the apex. Parameres short, simple ( Figs. 22–23 ). Southern Oaxaca, Mexico................................................................. .. P. nutans (Bates)

1’ Pronotum feebly convex; with small or medium sized, circular punctures. Elytral striae shallow, indicated by punctures or only marked along the posterior third of elytra. Meso-metasternal process with broad base, clearly narrowed towards the apex. Parameres long and varied in shape; with keels, notches, or folds............................................... 2

2. Elytra with distal part of interstriae prominent ( Figs. 42, 44, 47 , 48, 50, 53 )........................................ 3

2’ Elytra with distal part of interstriae not prominent ( Figs. 43, 46 , 49, 52 )...........................................5

3. Protibial inner border straight all along its length. Elytral surface punctate, with varied sculpturing. Parameres long, narrow, and gradually reduced towards the apex.................................................................... 4

3’ Protibial inner border clearly swollen on distal third. Elytral surface smooth, with scattered shallow punctures. Parameres short, broad, and abruptly reduced towards the apex ( Figs. 4-5 ). Veracruz, Mexico................... P. viduus (Newman)

4. Body elongate, pronotum narrowed towards the anterior end. Elytra ovate with acute apex; surface with irregularly-shaped punctures. Meso-metasternal process directed obliquely, recurved. Parameres with uniform anterior dorsal surface ( Figs. 16–17 ). Southern Chiapas, Mexico and Chimaltenango, Guatemala........................... P. crassesculptus (Bates)

4’ Body not elongate, pronotum widened towards the anterior end. Elytra subrectangular, with obtuse apex; surface with circular

punctures clearly impressed. Meso-metasternal process directed anteriorly. Parameres with swollen anterior dorsal surface ( Figs. 38–39 ). Northern Chiapas, Mexico............................ P. ixtacomitanus Ramírez-Ponce & Morón , n. sp. 5. Protarsomeres 1–4 wider and shorter than distal tarsomere ( Fig. 8 ). Protibia notably wider towards the apex, with divergent lateral borders ( Fig. 8 ). Parameres with dorsal surface transversely carinate ( Figs. 10–11 ). San Luis Potosi to Veracruz, Mexico............................................................... P. nectoctenus Ramírez-Ponce & Morón , n. sp.

5’ Protarsomeres 1–4 shortened, about as wide as distal tarsomere ( Fig. 26 ). Protibia slightly wider towards the apex, with convergent lateral borders ( Fig. 26 ). Parameres with dorsal surface flattened ( Figs. 28–29 ). Northern Oaxaca, Mexico.................................................................... P. matzapatlecus Ramírez-Ponce & Morón , n. sp.

Figures

FIGURES 20 – 25. Diagnostic structures in P. nectoctenus: 20) right proleg, 21) right antenna, 22) male genitalia in dorsal view, 23) male genitalia in lateral view, 24) spiculum gastrale, 25) female genital plates. Scale lines 1 mm.

FIGURES 42 – 47. Dorsal view of Pachystethus species: 42 a, b) P. viduus males; 42 c) P. viduus female; 42 d) P. viduus female, lectotype; 43 a) P. nectoctenus male; 43 b) P. nectoctenus female; 44 a) P. crassesculptus male; 44 b) P. crassesculptus female; 45 a, b) P. nutans males; 45 c) P. nu t an s female; 46 a, b) P. matzapatlecus males; 46 c) P. matzapatlecus female; 47 a) P. ixtacomitanus male; 47 b) P. ixtacomitanus female. Scale lines 1 mm.

FIGURES 48 – 53. Lateral view of Pachystethus species: 48) P. viduus a) male, b) female; 49) P. nectoctenus a) male, b) female; 50) P. crassesculptus male; 51) P. n u t a n s male; 52) P. matzapatlecus male; 53) P. ixtacomitanus male. Scale lines 1 mm.

FIGURES 2 – 7. Diagnostic structures in P. viduus: 2) right proleg; 3) right antenna, 4) male genitalia in dorsal view, 5) male genitalia in lateral view, 6) spiculum gastrale, 7) female genital plates. Scale lines 1 mm.

FIGURES 14 – 19. Diagnostic structures in P. nu t an s. 14) right proleg, 15) right antenna, 16) male genitalia in dorsal view, 17) male genitalia in lateral view, 18) spiculum gastrale, 19) female genital plates. Scale lines 1 mm.

FIGURES 36 – 41. Diagnostic structures in P. ixtacomitanus: 36) right proleg, 37) right antenna, 38) male genitalia dorsal view, 39) male genitalia lateral view, 40) spiculum gastrale, 41) female genital plates. Scale lines 1 mm.

FIGURES 8 – 13. Diagnostic structures in P. crassesculptus. 8) right proleg, 9) right antenna, 10) male genitalia in dorsal view, 11) male genitalia in lateral view, 12) spiculum gastrale, 13) female genital plates. Scale lines 1 mm.

FIGURES 26 – 35. Diagnostic structures in P. matzapatlecus: 26) right proleg, 27) right antenna, 28) male genitalia in dorsal view, 29) male genitalia in lateral view, 30) spiculum gastrale, 31) female genital plates, 32) labium, 33) labrum, 34) right maxilla, 35) left mandible. Scale lines 1 mm.