Onthophagus kokopygus 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 : 508-509

Onthophagus kokopygus Krikken & Huijbregts , new species

( Figs. 5 , 17 , 50–57 )

Type material. Holotype male (CMNC) from PNG: 34 mi E Port Moresby, Kokoda trail, 2000 ft, 16–17.vii.1974, S. Peck, T43–45. Paratypes listed in Appendix 1.

Diagnosis. Usually (rufous) medium-brown, more or less shiny, if darker legs remaining lighter brown; most of dorsum densely, finely ocellate-punctate. Pygidium canaliculate-punctate, as in next species. Tip of longer mesotibial spur incised. Clypeal border anteriorly bisinuate. Clypeofrontal transition with short transverse elevation. Eye foramina large, open behind, i.e., tapering posterior end of gena just not reaching occipital side; interocular distance approximately 2.5 eye widths. Genal tip subangular. Frons at most slightly raised, not ridged or tuberculate. Very small, body length usually 3.0– 3.5 mm.

Description (holotype, male). Body length slightly over 3 mm. Habitus convex, dorsum slightly deplanate. Color largely medium-brown, shiny, in spite of dense punctation on dorsum; venter and legs similarly brown. Pronotal, elytral, and pygidal punctation with short, whitish bristles (about as long as punctural diameter); underside with numerous short pale-brown bristles and longer setae; most of punctation ocellate, sharply defined, generally isodiametic.

Head brown, almost entirely finely, densely, distinctly punctate, punctural diameters largely similar. Clypeal border widely, evenly rounded from vague clypeogenal transition to broadly, slightly bisinuate anterior border, margin slightly reflexed; clypeogenal transition continuous at border; clypeogenal suture virtually effaced; clypeofrontal transition with low but distinct, short, arcuate, transverse elevation. Genal border virtually straight in front, lateral tip obtusely angular, posterior extension tapering and just not reaching occipital side. Frontal surface between eyes very slightly transversely raised (no distinct ridge). Eye foramina broadly subelliptic, with approximately 15 facet rows across widest point. Ratio interocular distance / maximum eye approximately 2.5.

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

Elytra brown, (on magnification) moderately shiny between interstrial punctures; scutellum indistinct, shape of base and apex unmodified; epipleuron glabrous, brown, matt. Elytra broad, with 8 fine, straight to slightly curved, striae; stria 7 evenly, very slightly curved in front, ending at humeral umbone; strial punctures fine, on disc mostly separated by 5–10 puncture diameters, very slightly crenulating interstriae. Interstrial surfaces hardly convex, with dense to crowded, shallow, fine, ocellate punctation, on disc usually 2–4 punctures over width between adjacent striae.

Antennal club light brown, scapus unmodified. Mentum shallowly emarginate in front. Postocular area of propectus concave, matt, posteriorly delimited by simple coxal-marginal ridge. Propectoral sides with several fine punctures. Metasternum shiny, anterior lobe slightly convex in front; metasternal lobe and disc with slight midline impression, finely, abundantly punctate; metasternal flanks shiny, with numerous fine, ocellate punctures. Abdominal ventrites matt, each laterally with more or less distinct rows of ocellate punctures, anal ventrite with more punctures, somewhat shiny. Pygidium with general surface slightly, evenly convex, canaliculate-punctate: with several well-defined, curvy channels (confluent punctures), shiny brown on raised “islands”; base with transverse ridge, apex broadly marginate.

Legs slender, generally shiny brown. Protibia robust, with 3+(1) larger external denticles (distal 3 long, more or less acuminate, proximal one obsolescent), distinctly separated by serration; proximal serration consisting of 6 small denticles; apico-external denticle oblique to tibial axis; apico-internal angle unmodified, terminal spur fine, elongate-acuminate, curved; protibial underside with low longitudinal crest; protarsus slender. Profemur robust, underside shiny, densely, irregularly punctate. Mesofemoral and metafemoral undersides with numerous 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, spine-bearing fossorial protrusions. Mesotarsi and metatarsi generally compact-complanate, with very fine sickle-shaped claws; mesotarsomeres and metatarsomeres 1 long, straight, unmodified, shorter than 2–5 combined. Terminal spurs on mesotibiae and metatibiae elongate, tapering (longer one on mesotibiae with rounded-hooked tip). Length proportions terminal spur // metatarsomeres 1–5 in approximate integers: 6//6/3/2/1/2.

Parameres distally with tapering-convergent stalks (full-face view), directed downward (lateral view), Fig. 17 .

Measurements in mm (dorsal view). Maximum width of head 1.15. Median length of pronotum 1.00, maximum width 1.70. Sutural length of elytra 1.60, maximum width combined 1.95.

Variation and sexual dimorphism. Sexes very similar. Body color varies from lighter rufous to dark brown. Female head at most with slight transverse swelling.

Comment. Onthophagus daymanus and O. kokopygus share some unique attributes (pygidial sculpture, mesotibial spur), which probably indicates they are closely related species.

Etymology. Name is a contraction, referring to type locality and characteristically sculptured pygidium.

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 40 – 57. Onthophagus species, body parts. 40 – 44, O. mimikanus, female holotype; 45 – 49, O. dayanus, holotype; 50 – 57, O. kokopygus, holotype (50 – 54), female paratype, E Port Moresby (55). — Head (full-face) 40, 45, 50, 55; pronotum (dorsal) 41, 46, 51; left elytron (dorsal) 42, 47, 52; protibia (upper side) 43, 48, 53; metatibia (underside) 44, 49, 54; elytral tips and pygidium 56; mesotibial apex, tarsus, spurs 57. Scale lines equal 1 mm.