Navigator pixii 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 : 544-549

Navigator pixii Moeseneder & Hutchinson , new species

( Figs. 1 A, 1C, 1D1–8, 1E3, 1G1, 1K, 2B, 9–11)

Gen 3 sp 1 Golding 2009: 47.

Material examined (44 specimens). Holotype, male ( Fig. 9 ): AUSTRALIA: Boggomoss , 4.5 km N of Glebe Weir, Queensland, 3–30.xii.2012, C. & S. Moeseneder, FIT, MIC 61086-002 , T159400 [QM]. Condition: undamaged . Allotype, female ( Fig. 11 ): AUSTRALIA: Boggomoss , 32.5 km NE of Taroom, Queensland, hatched 21– 22.vi.2013, C. & S. Moeseneder, ex larva from soil, MIC 61160-004 , T159399 [QM]. Condition: undamaged.

Paratypes, 34 males and 8 females: AUSTRALIA. QUEENSLAND : 1 ♂, Boggom 3, via Taroom , 12.xi.1996 - i.1997, Cook & Monteith, FIT, T34273 [QM]; 1 Ƌ, Boggomoss, 4.5 km N of Glebe Weir , 3–30.xi.2012, C. & S. Moeseneder, FIT, CET2143 [PMH]; 2 Ƌ, Boggomoss, 32.5 km NE of Taroom , hatched 23.i.2013, C. & S. Moeseneder, ex larva, CET 2141 , CET 2142 [ PMH] ; 1 ♀, Boggomoss , 32.5 km NE of Taroom, hatched 21– 22.i.2014, C. & S. Moeseneder, ex larva, CET 2145 [ PMH]; 3 Ƌ , 4.5 km N of Glebe Weir , 13.x–3.xii.2012, C. & S. Moeseneder, FIT, MIC 61079 -001, MIC61079-002 [MIC], MIC61079-003 [SAM]; 1 Ƌ, 4.5 km N of Glebe Weir , 3–30.xii.2012, C. & S. Moeseneder, FIT, MIC 61086 -001 [MIC]; 1 Ƌ/3 ♀, 32.5 km NE of Taroom , C. & S. Moeseneder, ex larvae (collected 23.vi.2013), MIC 61126 -004 [PMH]; MIC61125-014, MIC61126-009 [MIC], MIC61126-008 [ANIC]; 5 Ƌ/1 ♀, 32.5 km NE of Taroom , C. & S. Moeseneder, ex larva (collected 21–22.vi.2014), MIC 61160 -003, MIC61160-007, MIC61160-009 [MIC], MIC61160-005 [WAM], MIC61160-006 [ANIC], MIC61160-008 [AM]; 1 Ƌ/1 ♀, 33 km E of Taroom , 13.x.–3.xii.2012, C. & S. Moeseneder, FIT, MIC 61061 -002, MIC61061-001 [MIC]; 3 Ƌ, Taroom, 8.x–15.xii.2003, T. Jack & D. Kitchin, FIT, CET0605 [PMH] no specimen numbers [DK]; 3 Ƌ/1 ♀, Taroom, 6 km N on Hwy, 21.ix–17.xii.1997, G.B. Monteith, FIT, T159371, T159376, T159379, T159378 [QM]; 10 Ƌ/1 ♀, Taroom, 6 km N on Hwy, 17.xii.1997 – 4.iv.1998, G.B. Monteith, FIT (except T159383 pitfall trap), T159372, T159374, T159375, T159377, T159380, T159381, T159382, T159383, T159384, T159385, T159373 [QM]; 2 Ƌ, Oak Wells, 15.xii.2001 – 7.iii.2002, Monteith & Cook, FIT, T159391, T159393 [QM] ( Fig. 10); 1 Ƌ, Oak Wells, 15.xii.2001 – 7.iii.2002, Monteith & Cook, pitfall trap, T159392 [QM].

Diagnosis. Form: 9.6–14 mm, ovoid, dorsal surface coarsely punctate, often coalesced. Colour: black with green, purple, or gold metallic reflections. Head: clypeolateral declivity absent, clypeus widest preapically, clypeus apical margin linear, male antennal club enlarged. Elytron: posthumeral arch weakly sinuate, costae distinct, narrow. Abdomen: mesometasternal process undeveloped, female sternites distended, female pygidium elevated and visible in dorsal view. Legs: male metatibia internal margin bearing setose longitudinal groove, female inner metatibial spur spatulate.

Description. Holotype. Male ( Fig. 9 ). Length 9.8 mm, width 5.1 mm. Ovate, depressed. Head. Black with metallic green and purple reflections. Clypeus; clypeolateral ridge present; lateral margin linear, slightly divergent from antennal insertion, widest preapically; apical angles broadly arcuate to linear apex; lateral and apical declivity obsolete; disc flat, gradually inclined to moderately raised narrow lateral and apical margins; frons with distinct narrow medial longitudinal ridge extending to base of clypeus; disc with coarse, coalesced punctures, bearing long, erect, pale pilosity. Ocular canthus bearing few long setae apically. Antenna: scape black with green reflections, bearing long, pale setae along entire length, setal brush on posterior margin; pedicel black with brown apical margin; antennomeres 3–7 brown, bearing few long, pale setae; club brown, arcuate, 2 x length of antennomeres 2– 7, equal to length of head; antennomere 8 with setae medially on internal surface; antennomere 10 external surface uniformly brown. Thorax. Pronotum, black with green and purple reflections; basomedian margin linear ( Fig. 1 C, detail 1); basolateral margin linear, slightly angled anteriorly; basolateral angle slightly obtuse ( Fig. 1 C, detail 2); posterolateral margin linear, parallel, broadly arcuate medially, linear attenuate to anterolateral angle; anterior margin linear; lateral margin bearing ridges; disc with coarse punctures, rugulose toward anterolateral angle, bearing long, erect, pale pilosity. Scutellum black, elongate with broad base; coarsely punctate bearing long, erect, pale pilosity. Elytron, purplish brown with dark brown costae; narrowly exposing mesepimeron ( Fig. 1 D, detail 5); lateral margin with pronounced humeral umbone; posthumeral arch sinuate ( Fig. 1 D, detail 1), exposing metacoxa ( Fig. 1 D, detail 2), linear and broadly arcuate to apex ( Fig. 1 D, detail 4); disc coarsely punctate, mostly coalesced and eroding margins of costae, bearing long, pale, erect pilosity; humeral and apical umbones not distinctly raised ( Fig. 1 D, details 6 and 7); costae 1 and 2 distinctly raised, narrow; sutural costa largely eroded, not elevated between scutellar apex and preapical declivity; sutural apices bearing small spine. Mesometasternal process present as narrow low rounded elevation, declivous between mesocoxae, declivity bearing sparse pilosity. Metasternum black with purple reflections, sparsely punctate medially, finely rugulose laterally, bearing long, pale pilosity. Legs. Dark brown to black with green reflections; tarsomeres dark brown. Profemur dorsoventrally flattened, slightly attenuate to apex; ventral surface moderately punctate, bearing long, pale pilosity. Protibia elongate, bidentate with acute denticles, denticle 2 post median; dorsal surface with coarse punctures in loose rows, smaller at base of denticles, bearing erect, pale setae, setal brush sparse. Protarsomeres 1–5 longer than tibial length, bearing few pale setae. Mesofemur dorsoventrally distinctly flattened, parallel; ventral surface sparsely punctate, becoming rugulose along posterior margin, bearing long, pale pilosity. Mesotibia elongate; ventral surface coarsely punctate in longitudinal rows, bearing moderately long, pale pilosity; internal margin and dorsal surface moderately clothed in long, pale pilosity; external margin without distinct denticle; apex bispinose; spurs long fine, tapering. Mesotarsomeres 1–5 longer than tibial length, bearing few long, pale setae. Metafemur dorsoventrally distinctly flattened, elongate; anterior margin moderately arcuate; posterior margin linear; ventral surface sparsely punctate, bearing long, pale setae. Metatibia internal margin arcuate in apical half; ventral surface with coarse punctures loosely arranged in longitudinal rows, bearing sparse long, pale setae; internal margin with wide longitudinal groove bearing dense brush of long, pale setae with ginger base; dorsal surface with sparse long, pale setae; external margin bearing micro denticle medially; apex unispinose ( Fig. 1 K, detail 1); spurs long, fine, tapering. Metatarsomeres 1–5 longer than tibial length, bearing few long, pale setae. Metacoxa posterolateral angle weakly obtusely angulate ( Fig. 1 G, detail 1). Abdomen. Sternites black with purple reflections; sternites 2–5 with shallow, narrow longitudinal groove, light brown; sternites 3–6 with sparse punctures in 2–3 rows, bearing long pale pilosity, denser laterally. Pygidium, black with metallic green reflections, vertical, concentrically rugose with centre in middle of disc, bearing long, erect, pale pilosity on disc and apically. Genitalia ( Fig. 2 B). Phallobase narrowest at apex, broadest near base of parameres, 1.5 x length of parameres. Parameres narrow, parallel, gradually widening to apex; dorsal cleft base broad, slightly angulate medially, attenuate to apex.

Variation in paratypes. Males. Length 9.6–11.7 mm, width 5.0– 5.6 mm. Frons lacking medial longitudinal ridge. Pronotum black with golden green reflections, basomedian margin slightly concave. Scutellum with green and purple reflections or with blue reflections. Elytron brown with golden green reflections. Mesotibia bearing short, obtuse or short, acute medial denticle. Sternites green with purple reflections. Pygidium black with green and purple reflections or burgundy with blue reflections. Specimen T159393 from Oak Wells ( Fig. 10) dorsally and pygidium entirely beige-brown with gold reflections, lacking any green reflections, scutellum darker; ventrally and legs entirely bronze-brown, body medially lighter. Specimen T159392 from Oak Wells dorsally and pygidium entirely brown with violet-red reflections, lacking any green reflections, scutellum darker; ventrally and legs entirely dark bronze-brown with few green reflections, body medially lighter.

Allotype. Female ( Fig. 11 ). Length 12.6 mm, width 5.9 mm. Deeper body, stockier. Head. Black. Clypeus with microsetae. Frons without medial longitudinal elevation, bearing sparse, short setae. Antenna; scape without green reflections; club length equal to antennomeres 2–7, less than 0.5 x head length. Thorax. Pronotum black; posterolateral margin divergent then medially broadly arcuate; setae sparser, shorter. Scutellum setae sparse and short. Elytron brown, margins except suture darker brown; costa 4 distinct; disc bearing sparse setae. Metasternal pilosity sparser, shorter. Legs. Green reflections absent. Protibia tridentate, basal denticle small, premedial. Mesofemur rugosity absent. Mesotibia with acute medial denticle. Metafemur elongate; anterior margin moderately arcuate; posterior margin linear. Metatibia elongate, narrow; ventral surface bearing row of coarse punctures; internal margin without setose groove; external margin with small acute medial denticle; apex trispinose, medial spine barely noticeable; external spur broad, parallel, curved outward with arcuate apex, internal spur spatulate bilaterally expanded. Metatarsomeres 1–5 shorter than tibial length. Abdomen. Black, sternites distended ( Fig. 1 E, detail 1), bearing moderately long setae. Pygidium, black, centre of concentric rugosity at apex; at 45º angle to body ( Fig. 1 E, detail 3).

Variation in paratypes. Females. Length 12.5–14.0 mm, width 5.7–7.0 mm. Pronotum black with green reflections. Elytron brown. Metatibial medial denticle absent. Sternites dark brown. Pygidium dark brown, 30º angle to body.

Differential diagnosis. Differs from N. ruficornis and N. interior by absence of clypeolateral declivity and metacoxa posterolateral angle angulate. Differs from similar N. fossor by male metatibia internal margin bearing setose groove, from female by smaller size and ovoid shape.

Etymology. This species is named after the pixie, a mythical creature of British folklore. Pixies are said to be small and often inhabit moorland areas, which are hydrologically similar to boggomosses. Navigator pixii , like its namesake, lives a somewhat hidden existence and has hence eluded description until now.

Further observations. We measured body lengths of male N. pixii specimens (x̅ = 10.71, standard deviation = 0.04, n = 28) and males of the taxa nearest in length, Pseudoclithria adusta and an undescribed Pseudoclithria species from Wannamal, Western Australia (x̅ = 11.73, standard deviation = 0.07, n = 21) and found (at P = 8.73e- 7) that with 10.7 mm, N. pixii males are, on average, the smallest Australian Schizorhinini .

Remarks. Golding (2009) published an image of a male specimen of N. pixii captioned “ Gen 3 sp 1 Qld. 7mm ” without further comment and in the section of unplaced genera and species. The specimen bears ID CET0605 and resides in the collection PMH.

Ecology, development, and distribution. Navigator pixii is known from three areas in southeastern Queensland, Australia. In 1996–1997 a series of these beetles was collected by Queensland Museum staff 32.5 km northeast of Taroom in flight intercept traps at a site that the collectors named “Boggomoss BM03” (referred to as BM03 in the following) ( Fig. 12 ) ( Monteith & Burwell 1997). Invertebrate fauna was sampled by the museum in the area to assess impact of the planned Nathan Dam, approximately 9.75 km downstream of BM03. The dam is expected to produce a reservoir that extends to approximately 1 km of BM03 (SunWater 2016). Site BM03, which is at the same location as SunWater’s (2016) site 9, Boggomoss Reserve, is located in an area where underground water seeps naturally to the surface and the ground is permanently wet. Known as boggomosses, these areas may measure from several metres to hectares in diameter. The habitat where the flight intercept trap was installed was described in the report as “… dense grasses and reeds and with some sphagnum bog zones. Some temporary pools of free water. Sparse eucalypts. The insect traps were set among some stunted brigalow on the edge of the bog.” At BM03 one adult male was caught in a baited flight-intercept trap. The bait, however, was most likely not an attractant to the cetoniine. Two of the museum’s boggomoss sites are listed in the inventory of Australian Heritage Places as Boggomoss Area No 1 (Department of the Environment 2015a), which contains site BM03, and Boggomoss Area No 2 (Department of the Environment 2015b). A second series of N. pixii was caught by the QM at the southern end of a 7 km long, narrow remnant strip of vegetation along each side of the Leichhardt highway, 5–6 km north of Taroom ( Fig. 12 ). The area is administered as a stock route and was used in the past as a reserve for drovers to feed travelling cattle. Due to the small lateral extent, this habitat encompasses only approximately 1.6 km 2. The dominant trees in the vegetation strip where Navigator pixii were collected were brigalow ( Acacia harpophylla ) and ooline ( Cadellia pentastylis Mueller ; Surianaceae ). The Taroom stock route site is listed in the inventory of Australian Heritage Places as the Brigalow Invertebrate Site (Department of the Environment 2015c). During the museum’s study, the N. pixii specimens from this site were also collected in flight intercept traps, with the exception of one female, which was found in a pitfall trap. Despite installation of several flight-intercept traps we were unable to acquire further specimens from the site during our study, which may indicate a temporal difference or a lack of adult emergence-inducing triggers. Specimens of Navigator pixii from aforementioned sites were collected in an ecological community known as Brigalow. The Brigalow Belt Forest of Queensland and New South Wales, Australia is an ecological community of open forest and woodland that consists of a variety of trees of which the dominant and co-dominant species is usually Acacia harpophylla , commonly known as Brigalow tree. Acacia harpophylla is an Australian endemic wattle with dark grey bark that grows to a height of 10– 25 m. Brigalow communities have declined to 10% of their former range and are endangered (Australian Government Department of the Environment 2015).

Observations of living adults of N. pixii in their natural habitat have, as far as we know, not yet been made. Following our discovery of the larval habitat of Navigator fossor in Western Australia we searched for similar habitat in the BM03 area. We encountered 2–8 mm long larvae of cetoniine appearance in the detritus and in the soil under the leaves ( Fig. 14 F) at a depth of 5–20 mm. The larvae were free-living and not within or visibly associated with roots or dead wood, or specifically concentrated around any other matter. The layer of eucalypt leaves at the site was shallow, approximately 20 mm. Found larvae were relocated to a laboratory environment and, upon emergence, confirmed to be Navigator pixii . On 27 September 2015 during a visit to the boggomoss site during very dry weather we did not find larvae, which were present after less dry weather on all three previous visits. In captivity, male N. pixii were fully developed in pupal cells as late as 23 February. One of the pupal cells constructed by a wild-caught Navigator pixii larva was parasitised by Rutilia (Donovanius) lepida (Guérin- Méneville, 1843) ( Diptera : Tachinidae ). The N. pixii specimen was consumed and a single R. lepida hatched from the pupal cell. A captive-hatched female N. pixii was observed to ingest honey, which was offered immediately after eclosion; hence adult females will feed despite not having been found on flowers.

Collection of N. pixii with flight-intercept traps produced an approximate male to female ratio of 17:3. A small number of larvae were reared and the resulting male to female ratio was 4:5. The difference in sex ratios may indicate that females are more sedentary than males. When observed in laboratory conditions, females of N. pixii tended to bury themselves immediately when the ground was suitable. Males wandered longer and buried themselves less often, and random inspection of captive specimens showed males on the surface more often than females.

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 2. Navigator male aedeagi. A— Navigator fossor. B— Navigator pixii. C— Navigator ruficornis. Note: male N. interior are unknown.

FIGURE 9. Navigator pixii holotype, male.

FIGURE 11. Navigator pixii allotype, female.

FIGURE 12. Site map of Taroom and Boggomoss, Queensland. Red pentagons – collecting locations of Navigator pixii; Oak Wells collecting location not shown due to distance. Light green areas – forests of various compositions, dark green areas – Brigalow ecological communities and other Acacia harpophylla co-dominant communities. Solid light red polygons along roads – stock routes, cross-hatched red polygons – protected areas; grey shading—ground elevations. The two collecting locations at Taroom show label data, which was most likely simplified, not exact locations.

FIGURE 14. Navigator habitat. A – D— Navigator fossor (all images near or 10 km west of Menzies, Western Australia): A— Acacia leaf litter and branch thicket. B— Acacia with scattered Grevillea. C—male on leaf litter under Acacia. D—larva in decomposing leaf substrate. E – F— Navigator pixii (images at Boggomoss site BM 03, Queesland): E—collecting locations of adults and larvae. F—accumulations of dead leaves, predominantly from Acacia harpophylla, on the ground under which larvae were found.