Pachystethus matzapatlecus Ramírez-Ponce & Morón, 2012

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 : 15-17

Pachystethus matzapatlecus Ramírez-Ponce & Morón , new species

( Figs. 26–35 , 46 a–c, 52)

Type material (20 males, 5 females). Holotype male housed at IEXA with following label data: a) “ México, Oaxaca, Santiago Comaltepec, La Esperanza, 31-VIII-05. Mora, E. col.” (typeface), b) “Colecta directa en flor, 1550 m, Bosque mesófilo de montaña- Oreomunnea mexicana ” (typeface), c) our holotype red label. Allotype female housed at IEXA with following label data: a, b) same data as holotype; c) our allotype yellow label.

Paratypes (19 males, 4 females; CNIN, IEXA, MXAL) with our paratype yellow labels and following label data: “A. Ibarra. MEXICO. Oaxaca, Puerto Eligio, S. de Juarez 12-IX-82 ” (handwritten) (7 males, 1 female; CNIN); “A. Ibarra. MEXICO. Oaxaca, Metates, S. de Juárez. 16-IX-82 ” (handwritten) (8 males, 2 females; CNIN, IEXA, MXAL); “ Mexico: Oaxaca Metates Sierra de Juárez. 8-III-83 J. Bueno” (handwritten) (1 male, CNIN); “Km. 65 carr. Tuxtepec Oaxaca, México 18-IX-82 A. Ibarra” (handwritten) (2 males, CNIN); “A. Ibarra, México Oaxaca. Km. 65 Carr. Tuxtepec. Oax. 18-IX-82 ” (handwritten) (1 female, CNIN); “ 5 km W La Esperanza, 27-IX-1977, 1,500 m, J. Llorente” (typeface) (1 male, MXAL).

Description. Holotype: male. Length 9.0 mm, width 4.0 mm. Color shiny black on almost entire body; reddish dark brown on legs. Head. Clypeus subtrapezoidal, anterior border straight, briefly raised, and not directed forward; anterior angles widely rounded; clypeal surface rugose with abundant large punctures. Frontoclypeal suture straight, clearly defined. Frons slightly convex, glabrous, densely punctate; puctures rugose at center, more disperse on lateral and posterior margins. Punctures around eyes scattered. Antennal club slightly longer than the length of all preceding antennomeres combined; lamellar shape semiovate, nearly straight ( Fig. 27 ). Eyes medium size, ovate; ocular margin dorsally noticeable and setose. Eye canthus thick with glabrous, rounded apex and flattened surface; surface with shallow minute punctures. Mouthparts ( Figs. 32–35 ): maxillary basistipe flattened, with irregular punctation; labrum wide and sinuate; labium sinuate, as long as wide, with irregularly rugopunctate, setose prementum. Pronotum: wider than long, moderately convex; surface with scattered, small, round punctures; lateral borders angled with bulky sides and large, deep lateral pits; posterior angles raised. Mesoepimera briefly exposed over humeral calli. Space between mesocoxae wide; mesometasternal process long and stout, briefly projecting anteriorly past mesocoxa, with wide, rounded apex directed downward; metasternum covered with numerous wide punctures, sides moderately setiferous, mesial region glabrous with deep longitudinal sulcus. Elytra flattened and ovate, striae weakly impressed with disperse and shallow, small punctures; elytral costae well defined; elytral suture raised on posterior third; brief preapical slope; lateral margins nearly straight with scattered stout, short setae on epipleural area and other slender setae near margin. Epipleural fold narrow, briefly excavated in lateral view, abruptly narrowed after metacoxa. Scutellum : slightly longer than wide; lateral margins briefly angled, apex rounded; surface with irregular, large punctures. Abdomen: sternites with scattered setae on nearly continuous row of irregular, large punctures. Legs: protarsomeres 1–4 short and wide, as wide as protarsomere 5 and equal in length. Protibia stout, progressively widened distally, lateral borders divergent towards apex; external border with proximal denticle short and rounded; distal denticle long, slightly curved ( Fig. 26 ). Mesofemora with a well-defined longitudinal keel and setiferous punctures. Metafemora without keels. Metatibia with 3 deep transverse keels and spine-like, short setae; apex of metatibia clearly swollen. Metatarsomeres 1–2 longer than tarsomeres 3–5. Genitalia ( Figs. 28–31 ) parameres complex; shorter than the length of tectum; with upper part irregular; apices narrowed, upturned; lower part of parameres briefly curved backwards. Basal half of tectum wider than distal half, with outstanding posterolateral calli. Basal piece with long and rounded, pointed apodema. Spiculum gastrale ( Fig. 30 ) narrow; basal part straight with uniform width, shorter than lateral sclerites; associated plates large, subrounded, with numerous long setae near exterior border.

Allotype female. Length 11.0 mm, width 4.2 mm. Color shiny black on most of body surface; reddish dark brown on all legs. Antennal club as long as the length of funicle. Epipleural fold swollen and enlarged. Protibiae and protarsi narrower than in male. Genital plates elongate, subtriangular, with angled apex and scattered setae ( Fig. 31 ).

Paratypes (n = 27). Length: 9.0– 10.7 mm, width: 3.8–4.1 mm. Fifteen specimens (13 males, 2 females) are completely shiny black, with reddish brown legs and 12 specimens (9 males, 3 females) have the pronotum with reddish yellow lateral margins and black disc. Mesometasternal process in bicolored specimens appears slightly larger than in black specimens.

Diagnosis. Clypeus subrectangular. Pronotum with scattered small, circular punctures (approximate diameter 0.027 mm). Elytral surface nearly smooth, with striae weakly indicated by discontinuos rows of shallow, minute punctures; margins without bend. Protarsomeres 1–4 shortened, but slightly wider than protarsomere 5. Protibia stout, progressively widened distally; external border with proximal denticle short and rounded; distal denticle long, straight. Parameres short and complex with upper part narrowed, widely curved towards apex (Table 1).

Etymology. From the ancient indigenous Nahuatl language “ Matzapatlan ” a mythical city in the mountains of northern Oaxaca where the first mazateco or “ Ha Shuta Enima ” people lived.

Distribution, phenology, and natural history. This species is distributed in the humid slopes of Sierra de Juarez, northern State of Oaxaca in Mexico ( Fig. 54 ) between 650–1,550 m of elevation where cloud forests overlaps with tropical rain forest and coffee plantations. Adults are active during March, August, and September. Flowers of an unidentified species of Asteraceae are recorded as host for adults, and the immature stages remain undescribed.

Remarks. Pachystethus matzapatlecus has resemblance with P. ixtacomitanus and P. n e c t o c t e n u s, but may be distinguished from the former by the elytra with the posterior callus not prominent and a shallower punctation, and from the latter by the protibia thinner and protarsus thinner and elongate. The shape of parameres is also distinctive (Table 1).

Figures

FIGURE 54. Distribution of species of Pachystethus.

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.

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.