Nothochodaeus minotaurus Huchet, 2021

Huchet, Jean-Bernard, 2021, Two new species of Nothochodaeus Nikolajev, 2005 from Palawan Island, Philippines (Coleoptera: Scarabaeoidea: Ochodaeidae), Insecta Mundi 2021 (893), pp. 1-12 : 2-4

Nothochodaeus minotaurus Huchet , new species ( Fig. 1–4 , 20 )

Type material. Holotype female ( CJBH), labeled: a) rectangular, white paper, printed: “ PHILIPPINES, Palawan / El Nido , VI. 2012 / Flight interception trap / V. Gutierrez Lgt”; b) rectangular, framed, white paper: “ Coll. J.-B. Huchet ”; c) rectangular, red paper: “ TYPE ”; d) red paper: “ Nothochodaeus / minotaurus n. sp. / HOLOTYPE / J.-B. Huchet det. 2021”. Genitalia stored in a small glycerol vial, pinned under the specimen. To ensure the perenniality of this material, the holotype is intended to be deposited at the Muséum national d’Histoire naturelle, Paris.

One female paratype ( CJBH) labeled: a) “ PHILIPPINES, Palawan / Roxas, VI. 2012 / Flight interception trap / V.Gutierrez Lgt”. One female paratype ( CJBH) labeled: a) “ PHILIPPINES, Palawan / Roxas, XII. 2013 / Flight interception trap / V. Gutierrez Lgt”. Genitalia stored in a small glycerol vial, pinned under the specimens.

Diagnosis. Body medium-sized, robust, convex, densely pubescent, unicolored, uniformly chestnut-brown; surface nitid; the head quadrituberculate with a distinct acute tubercle on each side of the clypeal carina, and two other flattened tubercles, barely perceptible, on the vertex. The stridulatory peg is present.

Description. Holotype female ( Fig. 1 – 4 ). Length: 8.4 mm (from the apex of the mandibles to the apical part of the tergite VIII). Width: 4.3 mm (greater width of the pronotum). Head: Strongly transverse, sub-hexagonal, flattened dorso-ventrally. Surface shiny, long pubescent, the setae obliquely directed backwards; surface microreticulate covered with medium setiferous granules separated by approximately twice their diameter. Labrum transverse, dorsally convex, strongly emarginate and transversely split into two superimposed laminae in the middle front; dorsal surface with large setose punctures, the anterior edge pubescent. Eyes very large, globose, strongly produced laterad, lacking ventral projection of canthus. Anterior clypeal membrane transverse, trapezoidal, in thin hyaline tegumentary plate overhanging the labrum. Clypeus subtrapezoidal, slightly obliquely declivous forwards, the front margin distinctly beaded and pubescent on edge; clypeus separated from frons by a weakly curved carina ended by a distinct acute tubercle on both sides ( Fig. 3 ); the area behind the carina shallowly concave. Vertex bituberculate, the tubercles flattened, obsolete ( Fig. 1 ). Mandibles subequal, falciform, broadly scooped dorsally. Mentum subquadrangular, slightly transverse, the base sublinear, the sides slightly convex, weakly depressed; the disc densely pubescent; a median longitudinal groove extending nearly from the base to the insertion of the palps forward. Labium with 3-segmented palpi: basal palpomere very reduced, slightly curved; median palpomere strongly developed, securiform, 3–4× longer than the basal palpomere; distal palpomere elongate, fusiform, inserted at the inferodistal third of the median palpomere. Maxillae with 4-segmented palpi; lacinia and galea well sclerotized, distinctly separated. Galea well developed, subtriangular, the inner margin with ten long thick curved setae and three thinner apical setae, the latero-external edge glabrous. Galea subdivided into galea (distal part) and subgalea (proximal part) (respectively “proxagalea” and “distagalea” according to Nel and Scholtz (1990)). Lacinia in the shape of a thin longitudinal plate, apically acuminate as an elongated curved spur, its inner edge densely pubescent. Antenna 10-segmented, fawn-colored, the scape densely pubescent, the outer antennomere club segment distinctly brightened and pubescent at the upper edge. Pronotum: Transverse, convex, the lateral edges and base fringed with long setae, the outline entirely margined, the marge distinctly widening in the middle of the base forming a transverse bulge in a portion extending on both sides up to the level of the humeral callus. Anterior margin slightly convex behind the head, with a thin hyaline membrane in front. Front angles obtuse, the posterior ones regularly rounded. A short, barely impressed, median longitudinal furrow at base. Pronotal surface with double punctation consisting of long setiferous medium foveolate punctures mixed with small setose punctures, the setae obliquely directed anteriorly; surface shiny with two darkened foveae in the middle of each side. Scutellum sublinguiform, weakly depressed in front, the surface slightly concave with few scattered setose medium punctures. Elytra: Transverse, densely pubescent, their color similar to that of the pronotum. Surface with well impressed striae, consisting of sunken large points separated by about 1× their diameter; each puncture, rather deep, round, with a very short non-erect bristle along the internal anterior edge; interstriae weakly convex, with strong and tight punctation consisting of small setose granules, the setae oriented backward; juxta-sutural interstriae darkened, noticeably depressed. Humeral callus well developed. Abdomen: Strongly convex with six visible ventrites (III–VIII). The ventrites convex, shiny, with a transverse row of large darkened granules along their anterior edge; the granules setose, quite close in the median part of the ventrites (separated by ± 2× their diameter), more spaced on the sides (separated by ± 3–4× their diameter). Tergite VIII (pygidium) convex, the surface with large setose punctures not uniformly distributed, the setae denser in the apical part. Metasternal process subplanar with a thin, barely visible median darkened groove in the anterior half; mesocoxae widely separated. Stridulatory apparatus (sternite VI) present. Legs: Protibia tridentate externally, the basal tooth spinose, acute, very reduced. Femurs without accessory teeth, their surface with two parallel rows of setose punctures. First metatarsomere of equal length than tarsomeres 2–5 combined. Genitalia: Female terminalia rather weakly chitinized. Gonopode IX dimeric (one subcoxite and one coxite on each side), the terminal stylus IX lacking ( Fig. 4 ). Subcoxite IX barely sclerotized, roughly triangular, with two long setae at the apical end of the ventral edge; coxite IX elongated, digitiform, bearing about twenty long setae.

Sexual dimorphism. Unknown.

Etymology. In reference to the Minotaur, a twin-horned mythological creature.

Distribution. North Palawan (El Nido, Roxas) ( Fig. 20 ).

Remarks. From the presence of two distinct tubercles on the vertex and the outer 3rd protibial tooth located near the base, N. minotaurus Huchet , new species appears to be morphologically closest to Nothochodaeus maruyamai Ochi, Kon and Masumoto, 2013 from the Malay Peninsula but also to N. hirtus , from Java. It differs from N. maruyamai by the presence of two acute tubercles on each side of a distinctly raised clypeal carina (the clypeal carina is very thin, slightly raised, and weakly tuberculate on either side in N. maruyamai ). Additionally, the pronotal punctation of N. minotaurus Huchet , new species, is denser than that of N. maruyamai , and the setose punctures distinctly larger. N. minotaurus Huchet , new species is distinguished from N. hirtus by its smaller size, the conformation of the clypeal carina (very high and without tubercles in N. hirtus ). Finally, the pronotal punctation of N. hirtus is very distinct (very dense, consisting of small, tightly packed but non-contiguous setose granules).

In addition to similar coloration patterns, these three species share the presence of a pair of weakly raised tubercles on the vertex. Interestingly, other species belonging to the geographically distant genus Parochodaeus Nikolajev, 1995 present similar tubercles, as notably the neotropical species P. bituberculatus (Erichson, 1847) , inhabiting Peru and Chile, but also P.pudu Paulsen and Ocampo, 2012 , from Argentina (in this last species, the tubercles are nevertheless very prominent).

Dupuis (2005), based on a detailed study of three female representatives of the family ( Ochodaeus gigas Marseul, 1913 , O. miliaris Klug, 1832 and O. pocadioides Motschulsky, 1859 (this last species now included in the genus Parochodaeus Nikolajev, 1995 (Huchet 2016)) evidenced the presence of a trimeric gonopod IX (subcoxite/ coxite/stylus) within these taxa. A similar conformation has recently been demonstrated in the South African species O. congoensis Benderitter, 1913 , O. adsequa Kolbe, 1907 as well as in the genus Afrochodaeus Huchet, 2020 ( Huchet 2020). Although belonging to three distinct genera, all these species belong to the tribe Ochodaeini Streubel, 1846 . Interestingly, unlike representatives of the Ochodaeini , the gonopod IX of Nothochodaeini Nikolajev, 2015 (ie. Nothochodaeus Nikolajev, 2005 and Ceratochodaeus Huchet, 2017 ) is dimeric and lacks a terminal stylus ( Fig. 4 ). An exhaustive study of the female terminalia at suprageneric level would obviously be relevant to reach a definitive conclusion. Although rarely described and used, the morphology of female genitalia is revealed to be of great value within the systematics of the Ochodaeidae as evidenced by Ortuño (2007). Along with male genitalia, we are convinced that female terminalia bear relevant features that may be useful both in the specific identification of the taxa and to clarify the phylogenetic relationships between the different genera.

Figures

Figure 3. Nothochodaeus minotaurusHuchet, new species, head, frontal view (paratype), inset illustrating the two acute clypeal tubercles (Photo J.-B. Huchet, MNHN).

Figure 20.Distribution map of Nothochodaeus minotaurus Huchet, new species (red dots), and N. huxleyi Huchet, new species (yellow dots) on Palawan Island (the type locality indicated with a star).

Figures 1–2. Nothochodaeus minotaurus Huchet, new species, female holotype. 1) habitus, dorsal view. 2) habitus, latero-dorsal view (Photos J.-B. Huchet, MNHN).

Figures 4–5. Ochodaeidae, female terminalia. 4) Nothochodaeus minotaurus Huchet, new species (holotype), right part.5) Ochodaeus miliaris Klug, 1832, with stylus IX present (after Dupuis, 2005) (Cx: coxite; Ep: epipleurite; Sc: subcoxite; Te: tergite). (Fig. 5: photo courtesy of F. Dupuis; scale = 100 µm).