Oileus gasparilomi Cano & Schuster

Cano, Enio B. & Schuster, Jack C., 2012, A new species of Oileus Kaup (Coleoptera, Passalidae) from Guatemala, with a key to the species of the genus, ZooKeys 194, pp. 81-87 : 82-83

Oileus gasparilomi Cano & Schuster sp. n. Figures 17

Material examined.

Nine specimens.

Type material.

Holotype male, pinned: GUATEMALA: Quiché Dept., Municipio de Chajul, aldea Chel, camino a Cabá, 15°38'57.10"N, 91°01'10.25"W (DMS), 1795m, bosque nuboso, VI 2008. Col. A. González-Madrid (UVGC).

Paratypes. five males and three females, same data as holotype, pinned (UVGC, USAC, IEXA and IBUNAM).

Diagnosis.

Oileus gasparilomi is a macropterous species, closely related to the Oileus rimator complex of species. The clypeus with anterior border straight, the postocular sulcus divided by a keel and the pronotum not clearly bilobed (almost straight) separates the new species from Oileus rimator . Ventrodorsal basal sclerotizations of the phallus (autapomorphy of the genus Oileus according to Boucher (2005)) is present in dorsal view of the aedeagus (Figure 4).

Description. Head. Anterior border of labrum concave, dorsal surface granular. Clypeus inclined, anterior border straight, posterior border crenulate. Frontoclypeal suture slightly concave at center, external tubercles rounded. Frontal area inclined, smooth and shiny in front of Median Frontal Structure (MFS); frontal ridges feebly developed, inner tubercles absent. Frontal fossae glabrous and smooth, composed of three separated small fossae: the anterior separated from the slightly bigger medial one by a keel than runs laterally from the MFS, and this separated from the posterior by an incomplete keel. MFS of “striatopunctatus” type (see Reyes-Castillo 1970); sides of base of MFS subparallel, as wide as rest of MFS; center horn long with apex largely free and slightly directed upward, surpassing the posterior margin of clypeus (Figure 5); without dorsal groove. Supraorbital ridge bituberculate, anterior tubercle larger than posterior; posterior half of ridge elongate, with a small posterolateral impression. Canthus with apex rounded, apex forming a right angle. Eyes large, width = 0.98 mm (each eye). Head width (including eyes) = 9.2 mm. Ratio of sums of both eyes widths/total head width = 0.21; postocular sulcus wide, punctate and setose, divided by a central longitudinal keel. Ligula markedly protuberant medially, with central tooth small; setose punctations present laterally and posteriorly. Lateral lobes of mentum opaque towards the borders, with abundant setiferous punctations. Base of mentum medially glabrous and shiny; anterior central border convex; basal fossae oval, punctate-setose and opaque. Hypostomal process long, wide. Infraocular ridge present; proximal area concave and striate, basal area rounded, external area punctate-pubescent. Mandibles with three apical teeth (Figure 5); internal teeth wide, short, bifid in left mandible; both mandibles with a small basal tubercle (Figure 1); dorsal tooth occupies half length of the mandible; internal face smooth. Antennal club (Figures 1, 6 and 7) with the three segments very wide and subequal (width of penultimate segment = 3.5 mm).

Thorax. Anterior border of pronotum not clearly emarginate medially, almost straight. Lateral fossae of pronotum without coarse punctations. Pronotum with marginal groove narrow and smooth; anterior angles rounded. Pronotum with sparse, small and shallow punctations, moderately visible at low magnification. Mesosternum with lateral depression elongate, with elongate punctations, setose, with external border opaque. Mesepisternum with large opaque area. Metasternum laterally with dense setiferous punctations; disk shiny, delimited by 16-19 (up to 34) rugose punctations; marginal fossa setose, with coarse elongate punctations posterior part 1.5-2 times wider than the median part.

Elytra. Striae marked with defined punctations; striae 1-4 less well marked than 9-10, interstriae 1-5 with scarce micropunctations, more abundant and visible at lower magnification on interstriae 6-10. Anterior border of elytra vertical (Figure 4); humerus with tuft of setae on interstriae 5-10.

Wings. Well developed.

Legs. Profemur with anterior-ventral groove well marked, reaching the punctate setose apical area. Mesotibia with one (or two, if a spiniform keel is present) spine(s).

Abdomen. Marginal groove incomplete, occupies 3/5 of last sternite.

Aedeagus (Figures 2-4). In ventral view, phallus spherical; parameres and phallobase not fused; parameres without a longitudinal division. In dorsal view (Figure 4), ventrodorsal basal sclerotizations of the phallus present.

Dimensions (mm) (n = 9): total length 35.75-41.80, (µ = 38.26); elytral length 20.30-22.40, (µ = 21.35); pronotal length 8.4-9.6, (µ = 9.14); pronotal width 10.7-12.0, (µ = 11.74); humeral width 11.65-12.65, (µ = 12.07).

Larva. Unknown.

Etymology.

Named after Gaspar Ilóm, a native hero of the novel "Men of Maize" by Miguel Ángel Asturias. The collection locality is called "mountains of Ilóm”.

Distribution and ecology.

The species is known only from mid-altitude cloud forest from the type locality, near Chel Village, road to Cabá in Chajul, Quiché, Guatemala. The southernmost locality of the closest relative, Oileus rimator , is in the northern mountains of Chiapas, Finca La Trinidad, at Municipio El Bosque ( Quintero and Reyes-Castillo 1983), separated from the locality of the new species by approximately 260 km.

Commentaries.

Quintero and Reyes-Castillo (1983) cite one specimen of Oileus rimator (Truqui) from the Museum of Natural History, Paris (MNHN), identified by H.W. Bates as “Oileus” sagittarius Smith (an invalid, unavailable name), collected in Guatemala. They considered the locality as erroneous. The Guatemalan Oileus gasparilomi is closely related to the Mexican Oileus rimator and the specimen of the MNHN may have been confused by Quintero and Reyes-Castillo, but most probably the specimen was mislabeled. Consequently, we also consider the locality as erroneous.