Navigator interior Moeseneder & Hutchinson

Moeseneder, Christian H. & Hutchinson, Paul M., 2016, Navigator, a new endemic genus of Cetoniinae (Coleoptera: Scarabaeidae) from Australia, with descriptions of two new species and behavioural studies, Zootaxa 4173 (6), pp. 530-556 : 549-551

Navigator interior Moeseneder & Hutchinson , new species

( Figs. 1 G3, 1J, 13)

Material examined (2 specimens). Holotype, female ( Fig. 13 ): AUSTRALIA: central Australia , 88/2995 [ WAM]. Condition: Good. Left protarsomere 5 missing, right mesotarsomeres 1–5 missing . Paratype, female: 88/2997 [WAM]. Condition: Fair. Left protarsomeres 2–5 missing, left mesotarsomeres 2–5 missing, right mesotarsomeres 3–5 missing, right metatarsomeres 2–5 missing, left metatibia and internal spur missing.

Diagnosis. Form: 17.6–18.5 mm, dorsal surfaces coarsely punctate, often coalesced. Colour: black. Head: clypeolateral declivity present, clypeus widest preapically, clypeus apical margin weakly concave. Elytra: posthumeral arch weakly sinuate, costae distinct, narrow. Abdomen: mesometasternal process undeveloped, female sternites convex. Legs: female inner metatibial spur spatulate, metacoxa posterolateral angle spinose.

Description. Holotype. Female ( Fig. 13 ). Length 18.5 mm, width 9.6 mm. Ovate. Head. Black. Clypeus; clypeolateral ridge linear, divergent from antennal insertion, widest preapically, arcuate to apical margin, apical margin weakly concave medially; lateral declivity moderate, near vertical; disc flat with low medial ridge along basal half, gradually inclined to moderately raised lateral and apical margins, coarsely punctate, glabrous. Frons with indistinct low circular medial elevation declivous to clypeal base where broader; disc coarsely punctate glabrous, glabrous at base of ocular canthus. Ocular canthus bearing few short ginger setae apically. Antenna; scape dark brown-black, distally cincta of few pale setae; posterior margin with brush of long, ginger setae; pedicel dark brown-black, glabrous; antennomere 3–7 light brown with darker maculae, bearing few long, pale setae; club dark brown, equal to length of antennomeres 2–7, 0.5 x length of head; antennomere 8 internal surface with patch of short setae, antennomere 10 external surface light brown on ventral two-thirds. Thorax. Pronotum black; basomedian margin concave; basolateral margin linear, angled anteriorly; basolateral angle obtuse; posterolateral margin linear, convergent to post medial arc, then attenuate to anterolateral angle; anterior margin sinuate concave; lateral margin bearing ridges; disc coarsely punctate, denser and coalesced along lateral and apical margins, bearing sparse microsetae laterally. Scutellum black, base broad, elongate, broadly raised medially, with fine dense punctures, glabrous. Elytron, dark brown with costae brown-black; narrowly exposing mesepimeron; lateral margins parallel, exposing metacoxa at weakly sinuate posthumeral arch, broadly arcuate to apex, lateral margins exposing abdominal sternites; disc coarsely punctate, mostly coalesced, eroding margins of costae, bearing microsetae; humeral and apical umbones not distinctly raised; costae 1 and 2 distinct, narrow, costa 3 as apical remnant; sutural costa narrow, present as fine ridge in apical half, terminating at 90º angle. Mesometasternal process present as flat area between mesocoxae, vertically declivous at anterior margin of mesocoxae, setae in declevity short, black. Metasternum black, sparsely punctate, bearing microsetae medially, becoming rugulose laterally, bearing moderately long grey setae. Legs. Black, dark brown at base of denticles; tarsomeres black with brown apices. Profemur dorsoventrally flattened, slightly tapering to apex; dorsal surface sparsely punctate, denser and rugulose along anterior and apical margins, bearing long, ginger pilosity. Protibia elongate, narrow, tridentate, denticles long, acute, basal denticle smallest and premedial, not equidistant; dorsal surface with macropunctures loosely arranged in longitudinal rows, punctures smaller at base of denticles, clothed with few short, ginger setae, setal brush sparse. Protarsomeres equal to tibial length, bearing few short, ginger setae. Mesofemur dorsoventrally flattened, widest at midlength; ventral surface sparsely punctate, bearing moderately long, ginger setae. Mesotibia elongate; ventral surface with single longitudinal row of coarse punctures, bearing sparse, short, ginger setae; internal margin and dorsal surface moderately clothed with long, ginger setae; external margin bearing small acute medial denticle; apex bispinose, spurs long, fine, tapering. Mesotarsomeres equal to tibial length, bearing few short, ginger setae. Metafemur dorsoventrally flattened, broad; anterior margin broadly arcuate; ventral surface moderately punctate, bearing moderately long, sparse, ginger setae. Metatibia elongate, narrow, parallel; ventral surface with several longitudinal rows of punctures, bearing sparse, short, grey setae; internal margin and dorsal surface sparsely clothed with moderately long, grey setae; external margin bearing small acute medial denticle ( Fig. 1 J, detail 1); apex sinuate trispinose; external spur broad, parallel with arcuate apex; internal spur broader and spatulate with linear internal margin. Metatarsomeres shorter than tibial length, bearing long, dark, brown setae. Metacoxa posterolateral angle spinose ( Fig. 1 G, detail 3). Abdomen. Sternites dark brown, apical third of sternite 6 black; sternites evenly convex; sternite 6 2 x length of sternite 5; sternites 2–5 sparsely punctate medially, bearing micro setae, becoming moderately punctate in basolateral regions, bearing long, pale setae; sternite 6 punctate, setose across medial and lateral areas. Pygidium brown, 45º angle to body ( Fig. 1 E, detail 3), concentrically rugose with centre at apical third, glabrous, with small shallow puncture at basolateral angle.

Variation in paratype. Female. Length 17.6 mm, width 9.5 mm. Clypeolateral ridge parallel. Elytron black. Legs brown, markings almost absent. Pygidial basolateral punctures absent.

Males. Unknown.

Differential diagnosis. Differs from all other Navigator species by clypeus anterior margin arcuate and metacoxa posterolateral angle spinose.

Remarks. The two known specimens of N. interior are females and were donated to the WAM as part of the Edgar Francis Du Boulay collection in 1964 (based on correspondence from 17 August 1964 between the Director of the WAM and Edgar Francis Houssemayne of Glen Forrest, Western Australia). It is unclear how the specimens came into the collection since Francis Houssemayne Du Boulay (1837–1914) and his sons Edgar Francis Houssemayne Du Boulay (1880–1972) and William Lawrence Du Boulay (1882–1955) were all collectors and their collections seem to have been intermingled. We designate the specimen that is labelled with a collection locality as the holotype ; the other specimen becomes a paratype. Both are possibly over 100 years old, based on their provenance, the condition of the specimens and the style of handwriting on the labels. The holotype bears a label attached by R.M. Young in 1989, which incorrectly identifies the species as Pseudoclithria maura .

Distribution. Neither of the two beetles we examined carries specific location information; a printed label on the holotype reads “C. Australia ”. This may be a reference to either the central region of Australia or the territory of Central Australia as the southern region of what is now the Northern Territory was known as from 1927–1931. In either case, these regions encompass areas of at least 500 0 0 0 km2.

Etymology. We chose the word interior for this species. It is a reference to the Australian continent’s large, dry interior region and aptly reflects our vague knowledge of its distribution. This name is a noun in apposition.

Figures

FIGURE 1. Navigator characters. A—characters of the head (example N. pixii male): A 1 — margins laterally divergent, A 2 — head widest preapically, A 3 — shallow arcuate to linear anterior margin, A 4 — gradually inclined margins, A 5 — shallow preclypeus, A 6 — cross-section, A 7 — lateral declivity absent. B—characters of the head (example N. ruficornis female): B 1 — lateral declivity present, B 2 — deep preclypeus, B 3 — cross-section, B 4 — lateral declivity present. C—characters of the pronotum (example N. pixii male): C 1 — concave linear basolateral margin, C 2 — broad median angle of lateral margins, C 3 — coarsely punctate disc. D—characters of the elytra (example N. pixii male, except D 9): D 1 — weakly sinuate-linear posthumeral arch, D 2 — slightly exposed metacoxa, D 3 — elytral basal half parallel sided, D 4 — apical half of elytra broadly arcuate to apex, D 5 — slightly protruding mesepimeron, D 6 – 7 — indistinctly raised apical umbone, D 8 — visible pygidium D 9 — pygidium not well visible (example N. ruficornis). E—characters of the female abdomen: E 1 — distinctly convex and distended sternites, E 2 — pygidium in normal plane (example N. ruficornis), E 3 — pygidium in elevated plane (example N. pixii). F—character of the abdomen: F 1 — undeveloped mesometasternal process. G—metacoxa posterolateral angle: G 1 — angulate (examples N. pixii and N. ruficornis), G 2 — broadly arcuate (example N. fossor), G 3 — spinose (example N. interior). H – K: characters of the metatibia: H— Navigator fossor female: H 1 — spatulate internal spur, H 2 — unidentate, H 3 — trispinose apex. I— Navigator ruficornis female: I 1 — large, median denticle, I 2 — trispinose apex. J— Navigator interior female: J 1 — small, median denticle. K— Navigator pixii male: K 1 — unispinose apex. Note: cross-sections in A and B are from clypeal anterolateral angle to clypeolateral margin, not in transverse axis.

FIGURE 13. Navigator interior holotype, female.