Proculus reyescastilloi Delgado and Mora-Aguilar, 2014

Delgado, Leonardo & Mora-Aguilar, Eder F., 2014, Proculus reyescastilloiDelgado and Mora-Aguilar (Coleoptera: Passalidae: Proculini): A New Species from the Region of Chimalapas, Oaxaca, Mexico, The Coleopterists Bulletin 68 (1), pp. 91-94 : 91-94

Proculus reyescastilloi Delgado and Mora-Aguilar , new species

( Figs. 1–5 )

Type Material. Holotype male labeled:“ MÉXICO:

Oaxaca, San Miguel Chimalapa, San Antonio,

91

El Gringo, 10-VI-2013, Alt. 1,600 m, bosque mesófilo/ 16°40′43″ N, 94°15′46″ W, en tronco, E. Mora y L. Delgado cols.”. Five male and four female paratypes with same data as the holotype .

The holotype and one female paratype are deposited in IEXA . Two paratypes are deposited in UVGC , and one paratype is in each of the following collections: MNHN, USNM, MZSP, CNIN, EMAC , and LLDC.

Description. Holotype male ( Fig. 1 ). Total length 70.1 mm, pronotal length 18.8 mm, elytral length 37.6 mm, pronotal width 26.3 mm, elytral

width 26.5 mm, cephalic width 21.2 mm. Dorsal and ventral surfaces shiny black. Head with dorsal surface completely glabrous, except in regions lateral to the vertex; clypeus thin; frontoclypeal suture distinct laterally, absent between internal tubercles. Frontal ridges lacking; internal tubercles short, scarcely surpassing the frontoclypeal suture; median frontal structure with short, central tubercle without free apex ( Fig. 2 ). Anterior border of labrum concave; dorsal mandibular tooth larger than apical mandibular teeth, with broad base and distal margin forming a right angle from the anterior teeth in lateral view ( Fig. 3 ); external outline of mandibles rounded in ventral view, external side of mandibles planar in ventral view. Ligula between insertions of labial palpi wide and strongly concave, base and sides with long setae, anteriorly trapezoidal, apex laterally bidentate and medially deeply emarginate, surface shiny. Lateral lobe of mentum longitudinally tumid, center of mentum anteriorly semitrapezoidal with apex emarginate. Terminal article of labial palpi shorter than half the length of 2 nd article. Pronotum smooth, lateral fossae glabrous. Scutellum with dense, short setae. Mesosternum with setae on posterior sides and mesosternellum. Metasternal disc delimited partially by dense setae, marginal groove shallow. Elytral striae with shallow punctures, elytral intervals smooth. Anterior margin of elytra and humeri setose, setae on 10 th elytral interval posteriorly to basal 2/5 of elytra. Mesotibiae with 2 spines on external border. Aedeagus with median lobe symmetrical, apex short and rounded in lateral view; lateral lobes expanded, not sinuate in lateral view; basal piece short ( Figs. 4–5 ).

Paratypes. 5 ♂♂, 4 ♀♀. Variation is mainly noted for measurements of the paratypes: Total length 57.9–76.5 mm, pronotal length 15.9–21.9 mm, elytral length 31.3–39.5 mm, pronotal width 21.4–29.7 mm, elytral width 21.3–29.5 mm, cephalic width 17.8–23.4 mm.

Etymology. We respectfully dedicate the name of this species to Pedro Reyes-Castillo as recognition of his important and extensive contributions to the knowledge of the beetles of the family Passalidae .

Taxonomic Remarks. Proculus reyescastilloi is distinguished from the other species of this genus by the following combination of characters: Dorsal surface shiny, dorsal mandibular tooth large, with broad base and distal margin forming a right angle from the anterior teeth in lateral view, and apex of ligula laterally bidentate and medially deeply emarginate. The shape of the aedeagus is also diagnostic ( Figs. 4 and 5 ). The new species most closely resembles Proculus burmeisteri Kuwert , but it is distinguished by having the distal margin of the dorsal mandibular tooth forming a right angle in lateral view (angle acute in P. burmeisteri ); the tip of the ligula laterally bidentate with medial emargination apically (apex acute in P. burmeisteri ); and the aedeagus with a symmetrical median lobe, lateral lobes with apices rounded, and not sinuate in lateral view (aedeagus with an asymmetrical median lobe, projecting lateral lobes with blunt apices, and sinuate in lateral view in P. burmeisteri ).

Distribution. Proculus reyescastilloi is the first known species from Oaxaca, Mexico. It is currently known only from the type locality, situated in the southeastern portion of the state, in the region of Chimalapas. The type locality and surrounding areas present a rugged topography with ravines and hills with moist cloud forests ranging from about 1,450 to 1,800 m in elevation. The cloud forests of the Chimalapas region are isolated from the cloud forests of the Meseta Central de Chiapas and the Sierra Madre de Chiapas by drier lowlands. For the species of Proculus, Schuster et al. (2003) suggested several events of biogeographic vicariance related with the formation of dry valleys separating wet mountain regions, which presumably facilitated speciation. The isolation and flightlessness of P. reyescastilloi suggest than this species is restricted to the mid-elevation cloud forests of this region, and as in other species of this genus, it is a vulnerable species because of their dependence on the presence of large-diameter trees for their life cycle.

Biology. The specimens of P. reyescastilloi were found in galleries of rotten fallen logs of trees locally known as “chinini de monte” ( Persea sp. , Lauraceae ). A single gallery contained five specimens. The host trees were more than 60 cm in diameter and showed evidence of the activity of these beetles in the form of wood shavings.

KEY TO THE SPECIES OF THE GENUS PROCULUS KAUP (modified from Schuster et al. 2003, figures correspond to those of same work)

1. Dorsal mandibular tooth large (fig. 2a)........2

1′. Dorsal mandibular tooth small or indistinct (figs. 2b–2d)..................................................5

2. Elytra matt, elytral setae on the 10 th interval extending past the middle of the elytra; lateral lobe of mentum flat; anterior border of labrum slightly bisinuate or nearly straight..............4

2′. Elytra shiny, elytral setae on the 10 th interval not extending past the middle of the elytra; lateral lobe of mentum tumid or protruding ventrally, forming a longitudinal ridge; anterior border of labrum concave......................3

3. Dorsal mandibular tooth with distal margin forming an acute angle in lateral view; ligula with acute apex; aedeagus with median lobe asymmetrical, lateral lobes projected with the apex blunt, sinuate in lateral view (eastern Guatemala; El Portillo, Santa Bárbara, Celaque, Honduras) ......... P. burmeisteri Kuwert, 1891

3′. Dorsal mandibular tooth with distal margin forming a right angle in lateral view; ligula bidentate apically, medially emarginate; aedeagus with median lobe symmetrical, lateral lobes rounded apically, not sinuate in lateral view (Chimalapas, Oaxaca, Mexico)..... ........................... P. reyescastilloi , new species

4. Elytral setae on the 10 th interval present from the base to past mid-elytron; external edge of mandible angular when viewed from above; pronotum matte (Sierra del Norte de Chiapas, Mexico; Cuchumatan Mtns., Huehuetenango, Guatemala; possibly Colombia) ..................... ................................ P. opacus Kuwert, 1891

4′. Elytral setae on the 10 th interval present almost to elytral apex; external edge of mandible rounded when viewed from above; pronotum shiny (Sierra del Norte de Chiapas, Mexico; Sierra Santa Cruz, Sierra de las Minas, Cerro San Gil, Guatemala; possibly Costa Rica) ................. P. opacipennis (Thompson, 1857)

5. Elytral setae on the 10 th interval present only on humeral angle; lateral lobes of aedeagus 1/2 as long as basal piece; horn of median frontal structure with tip not obviously free.............6

5′. Elytral setae on the 10 th interval present almost to elytral apex; lateral lobes of aedeagus expanded, same length as basal piece; horn of median frontal structure with tip obviously free (possibly Veracruz, Sierra Madre de Chiapas (Soconusco), Mexico; coastal volcanic range, Guatemala) ........ P. goryi (Melly, 1833)

6. Lateral lobes of mentum flat; aedeagus small (fig. 5 f); internal frontal tubercles small (fig. 4 f), located 1/4 of distance from anterior clypeal border to horn of median frontal structure; dorsal mandibular tooth not distinct (fig. 2d); lateral pronotal fossae with setae (mountains NW of Yoro, Honduras).............. ............................. P. jicaquei Schuster, Cano and Reyes-Castillo, 2003

6′. Lateral lobes of mentum protruding ventrally forming a longitudinal ridge; aedeagus large (fig. 5a); internal frontal tubercles large (fig. 4a), located 1/3 or more of distance from anterior clypeal border to horn of median frontal structure; dorsal mandibular tooth distinct (fig. 2c); lateral pronotal fossae glabrous ( Belize; Sierra Santa Cruz, Sierra de las Minas, Sierra de Merendón, eastern Sierra de los Cuchumatanes, Guatemala; San Pedro Sula, Honduras)....... P. mniszechi Kaup, 1868

Figures

Figs. 1–5. Proculus reyescastilloi, holotype. 1) Habitus; 2) Head, dorsal view; 3) Head, lateral view; 4) Aedeagus, ventral view; 5) Aedeagus, lateral view. Figs. 1–2 scale = 10 mm; Figs. 3–5 scale = 5 mm.