Lepanus gubara Gunter & Weir, 2019

Gunter, Nicole L. & Weir, Thomas A., 2019, Revision of Australian species of the dung beetle genus Lepanus (Coleoptera: Scarabaeidae: Scarabaeinae): key to species groups and description of 14 new species from the L. pygmaeus species group, Zootaxa 4564 (1), pp. 41-80 : 63-67

Lepanus gubara Gunter & Weir , new species

( Figs. 5D , 8D , 10D , 14 )

Type series. Holotype: ♂ “AUST: NT: Kakadu NP, 25kmS Jabiru , Gubarra Spring, Rainforest 14-22. XII.93, FIT S&J Peck 93-127” [12°40'00"S, 133°08'00"E] / “Canadian Museum of NATURE CMNEN 00030233 ” / “ANIC Database 25-065549” / “ Lepanus NT8 det. T.A.Weir 2018 ” in ANIC. Paratypes: Northern Territory: Kakadu National Park, 25 km S Jabiru, Gubarra Spring, [12°40'00"S, 133°08'00"E], 14– 22.xii.1993, S.B. & J. Peck ( CMNEN-00030232 ♀ in CMNC); The Amphitheatre, Nitmiluk National Park , 14°09'00"S, 132°23'00"E, 16.iii.1995, G.B. Monteith & H. Janetzki (T 111952 ♂ in QM, T 111950 in QM ♀) .

Description. Uniform dark brown in colour. Antennal clubs black.

Total length: 2.1 mm. Holotype measurements: Total length 2.1 mm, elytral width 1.4 mm.

Male: Head: U-shaped between clypeal teeth, which are short and upturned. Margin slightly angulate at clypeogenal suture. Genal angle weakly defined. Basal carina present but interrupted medially. Dorsal part of eyes narrow in size, separated by interocular space approximately 15 times eye width (30: 2); eye canthus nearly dividing eye. Head 1.05 × wider than long (37:35).

Prothorax: Hypomeral surface finely reticulate with light punctation. Hypomeral striae at least half the length of hypomeron. Pronotum 1.55 × wider than long (58:37).

Elytra: Striae 1–5 narrow and double, with very fine punctate edges. All striae on disc not equal width, striae 6–7 are weaker and narrower; elytral flange and groove narrow. Elytra 1.15 × wider than long (70:60).

Legs: Front edge of protibiae deeply angulate; apical digit somewhat elongate and sharp; 2 teeth on outer edge. Inner edge of metatibiae almost straight. Metatarsi with 2nd tarsomere subequal to the 5th. Tarsal claws small and toothed.

Abdomen: Pygidium with tear-drop shape depression containing an inverted V-shape tubercle, positioned in upper third of the depression. Depression occupies at least half size of disc and just extending under the virtually straight upper edge of pygidium; secondary basal line not evident. Abdominal surface smooth with reticulations right across. Segment 6 punctate.

Pterothorax: Medial lobe of metaventrite finely punctate and broadly margined between mesocoxae. Lateral lobe of metaventrite smooth and punctate with setae. Meso-metaventral suture very slightly arched. Mesoventrite with slight notch anteriorly. Mesoventrite smooth, virtually impunctate. Mesepimeron smooth. Metanepisternum reticulate.

Female: As per the L. pygmaeus species group.

Etymology. Named for the type locality Gubara, Kakadu National Park. The locality label of the holotype lists “Gubarra Spring”, however the correct spelling for the locality is Gubara ( Parks Australia 2017; Kakadu National Park Visitor Guide).

Distribution. Known from only four specimens collected from Kakadu National Park and Nitmiluk National Park from the Northern Territory, in the ARP bioregion ( Fig. 14 ). All specimens have been collected in rainforest or open forest. Given the limited collecting in the ARP bioregion and surrounding PCK, DAC, ARC, CEA, and GFU bioregions, and presence in both open and closed forest, L. gubara is likely more widespread than currently reported.

Comments. Lepanus gubara was unknown at the time when the informal nomenclature for undescribed species of Lepanus was reported ( Yeates et al. 2011) but was designated the informal name “ Lepanus NT8” within this revision. The only known specimens were collected in flight-intercept traps and by pyrethrum. This species is superficially similar to L. pungalina but both males and females L. gubara can diagnosed by the virtually impunctate mesoventrite, secondary basal line of pygidium not evident, absence of reticulation on the head between clypeogenal suture and apical edge, and punctation of the sixth abdominal ventrite (heavier in L. gubara ).

Figures

FIGURE 5. Habitus of species within the Lepanus pygmaeus species group. A, Lepanus andersonorum; B, Lepanus crenidens; C, Lepanus feehani; D, Lepanus gubara; E, Lepanus guthrieae; F, Lepanus lentil. All specimens in comparative scale. Scale bar 1 mm.

FIGURE 8. Pygidial configuration of species within the Lepanus pygmaeus species group. A, Lepanus andersonorum; B, Lepanus crenidens; C, Lepanus feehani; D, Lepanus gubara; E, Lepanus guthrieae; F, Lepanus lentil; G, Lepanus lingziae; H, Lepanus mckenziei; I, Lepanus menendezae. All specimens in comparative scale. Scale bar 0.2 mm.

FIGURE 10. Left, dorsal, and right view of aedeagi of species within the Lepanus pygmaeus species group. A, Lepanus andersonorum; B, Lepanus crenidens; C, Lepanus feehani; D, Lepanus gubara; E, Lepanus guthrieae. Not in comparative scale, given size difference aedegi are roughly grouped in three size classes as per lower left schematic and scaled accordingly. Size class indicated by shaded silhouette and 0.2 mm scale bar.

FIGURE 14. Map of known records for 10 species within the Lepanus pygmaeus species group overlaid with predicted distribution boundary of L. pygmaeus (dashed line) taken from Fig. 13 map.