Onthophagus kokocellosus Krikken & Huijbregts

Krikken, J. & Huijbregts, J., 2013, New Guinea Onthophagus: taxonomy of ten small, unicolored new species (Coleoptera: Scarabaeidae: Scarabaeinae), Zootaxa 3619 (5), pp. 501-525 : 510-511

Onthophagus kokocellosus Krikken & Huijbregts , new species

( Figs. 7 , 18 , 64–68 )

Type material. Holotype male (CMNC) from PNG: Iora Creek, 17 km S Kokoda, Kokoda Trail, 1400 m, 3–6.viii.1976, O. Kukal, carrion, montane rainforest. Paratypes listed in Appendix 1.

Diagnosis. Dorsum generally black, matt, due to dorsum being crowded with large ocellate punctures. Pygidium similarly ocellate-punctate, contrary to the two preceding species (which have canaliculate-punctate pygidia). Clypeal border anteriorly bisinuate. Clypeofrontal transition of male with slight transverse elevation. Eye foramina large, shortly open behind, i.e. tapering posterior end of gena not reaching occipital side; interocular distance approximately 3 eye widths. Genal tip distinct, shortly rounded. Frons of male with slight transverse ridge, between (and not reaching) eyes. Proximal protibial denticle minimal, almost fully sunk into proximal serration. Small, body length usually 4.5–5.0 mm. Note the comment under the narrow-eyed O. kukali , described below, which looks like an underdeveloped O. kokocellosus .

Description (holotype, male). Body length approximately 4.5 mm. Habitus convex, dorsum slightly deplanate. Color largely black, matt due to crowded punctation on dorsum; parts of underside, and legs, brown. Pronotal, elytral, and pygidial punctation with short, whitish bristles (shorter than punctural diameter); underside with numerous short pale-brown bristles and longer setae; most of punctation ocellate, sharply defined, generally isodiametic.

Head black, almost entirely finely, distinctly, densely punctate, punctural diameters largely similar. Clypeal border widely, evenly rounded from vague clypeogenal transition to broadly bisinuate anterior border, margin not reflexed; clypeogenal transition virtually continuous at border; clypeogenal suture virtually effaced; clypeofrontal transition with slight, short, transverse elevation. Genal border very widely rounded in front, lateral tip shortly rounded, posterior extension tapering and just not reaching occipital side. Frontal surface between eyes with very slight transverse elevation, not reaching eyes. Eye foramina broadly subelliptic, with approximately 17 facet rows across widest point. Ratio interocular distance / maximum eye slightly less than 3.

Pronotum black, hardly shiny between crowded, ocellate punctation; surface moderately, evenly convex (lacking midline impression); anterior declivity gradual, unmodified; anterior and lateral borders finely marginate; base very finely marginate; anterior section of lateral border widely rounded anterolateral angle fully rounded; posterior section of lateral border extremely slightly concave (full-face view), posterolateral angle distinct, but rounded off; pronotal lateral and basal borders widely rounded in dorsal view.

Elytra black, (on magnification) shiny between interstrial punctures; scutellum indistinct, shape of base and apex unmodified; epipleuron glabrous, brown, matt. Elytra broad, with 8 straight to slightly curved, striae; stria 7 evenly, very slightly curved in front, ending at humeral umbone; strial punctures moderately distinct, on disc mostly separated by 2–4 puncture diameters, crenulating interstriae. Interstrial surfaces very slightly convex, with crowded, shallow, ocellate punctation, on disc usually 2–3 punctures over width between adjacent striae.

Antennal club yellow-brown, scapus unmodified. Mentum shallowly emarginate in front. Postocular area of propectus concave, matt, posteriorly delimited by simple coxal-marginal ridge. Propectoral sides with numerous (partly ocellate) punctures. Metasternum shiny, anterior lobe very slightly prow-shaped in front; metasternal lobe and disc with slight midline impression, finely punctate; metasternal flanks shiny, with numerous ocellate punctures. Abdominal ventrites matt, each laterally with more or less distinct rows of ocellate punctures, anal ventrite with more punctures, somewhat shiny. Pygidium brown, matt, but shiny between punctures; base with transverse ridge, sides and apex marginate; surface slightly, evenly convex, with crowded, strong, ocellate, bristlebearing punctures, toward apex punctures smaller.

Legs slender, generally shiny brown. Protibia robust, with 3+(1) larger external denticles (distal 3 long, subacuminate), distinctly separated by serration; proximal serration (from obsolescent denticle to base) consisting of 5–6 small denticles; apico-external denticle oblique to tibial axis; apico-internal angle unmodified, terminal spur strong, elongate (tips worn off?); protibial underside with low longitudinal crest; protarsus slender. Profemur robust, underside shiny, with densely punctate. Mesofemoral and metafemoral undersides with fewer, finer, scattered punctures. Mesotibiae and metatibiae very strongly dilated distad to transversely subelliptic crest, which is fringed with short fossorial spines below, and some long, fine spines above; externally with 2 slight, spinebearing fossorial protrusions. Mesotarsi and metatarsi generally very slender, with fine sickle-shaped claws; mesotarsomeres and metatarsomeres 1 long, straight, unmodified, slightly shorter than 2–5 combined. Terminal spurs on mesotibiae and metatibiae elongate, tapering. Length proportions terminal spur // metatarsomeres 1–5 in approximate integers: 5//9/4/2/2/5.

Parameres with tapering-convergent stalks (full-face view), bent downward (lateral view), Fig. 18 .

Measurements in mm (dorsal view). Maximum width of head 1.5. Median length of pronotum 1.5, maximum width 2.3. Sutural length of elytra 2.3, maximum width combined 2.6.

Variation and sexual dimorphism. Females very similar, head protrusions virtually effaced. Variation mainly in body size.

Etymology. Name is a contraction, referring to type locality and abundance of ocellate punctation.

Figures

FIGURES 1 – 8. Habitus (oblique view) of Onthophagus species, with indication of body length. 1, O. acerus, holotype ,, 6 mm; 2, O. aceroides, holotype, 5 mm; 3, O. baiyericus, holotype, 5 mm; 4, O. mimikanus, female holotype, 6 mm; 5, O. kokopygus, holotype, 3 mm; 6, O. daymanus, holotype, 4.5 mm; 7, O. kokocellosus, holotype, 4.5 mm; 8, O. bituberoculus, female paratype, Timika, 7 mm.

FIGURES 13 – 24. Parameres (lateral view) of Onthophagus species. 13, O. acerus, holotype; 14, O. aceroides, holotype; 15, O. baiyericus, holotype; 16, O. daymanus, holotype; 17, O. kokopygus, holotype; 18, O. kokocellosus, holotype; 19, O. bituberoculus, holotype; 20, O. kukali, holotype; 21, O. kokodentatus, holotype; 22 – 23, O. dissidentatus, paratype, Wau (22), paratype. N Port Moresby (23); 24, O. ofianus, holotype. Scale lines (on top of relevant parameres) equal 0.5 mm.

FIGURES 58 – 73. Onthophagus species, body parts. 58 – 62, O. bituberoculus, holotype; 63, O. bituberoculus (or near), male; 64 – 68, O. kokocellosus, holotype; 69 – 73, O. kukali, holotype. — Head (full-face) 58, 63, 64, 69; pronotum (dorsal) 59, 65, 70; left elytron (dorsal) 60, 66, 71; protibia (upper side) 61, 67, 72; metatibia (upper side) 62, (underside) 68, 73. Scale lines equal 1 mm.