Lepanus ustulatus (Lansberge, 1874)

Gunter, Nicole L. & Weir, Thomas A., 2021, Revision of Australian species of the dung beetle genus Lepanus (Coleoptera: Scarabaeidae: Scarabaeinae): review of the L. ustulatus, L. storeyi, and L. nitidus species groups and description of eight new species, Zootaxa 4923 (1), pp. 1-66 : 5-12

Lepanus ustulatus species group

This group includes five species, all of which have been sequenced and form a strongly supported monophylum (see Fig. 1 ).

Diagnosis. The L. ustulatus species group is identified by their large size (> 3.5 mm) and by having a transverse sinuate fold across the base of the pygidium. The front edge of the protibia is truncate, the apical spur is absent in males and the apical digit is absent in females ( Fig. 2 A–B). All species share the following characteristics. Occasional exceptions are listed in brackets.

Length: 3.5–6.5 mm.

Males. Head: Broad U-shape between clypeal teeth that are not upturned. Margin of head completely bordered, rounded; genal angles slightly prominent, angulate at clypeogenal suture. Mentum thickened anteriorly, reticulate with long setae basally and apically. Dorsal part of eye wide.

Prothorax: Pronotum anterior angles sharp. Basal edge rounded, with a fine margin medially, and without punctures. Lateral margins bordered. Hypomeral surface reticulate. Hypomeral stria absent.

Elytra: Intervals very finely punctate, striae superficial and impunctate. 8th stria slightly curving inwards posteriorly.

Legs: Protibia with tooth on underside near base of tarsus and two or three teeth on the outer edge. Apical digit short and broad. Front edge of protibia truncate; apical spur absent. Metatarsus with 5 tarsomeres with 2nd tarsomere the longest. Basal metatarsomere lobed on inner edge. Tarsal claws small and simple.

Abdomen: Pygidium with a transverse sinuate fold across the base. Abdominal ventrites reticulate for full width. Suture between ventrites 5 and 6 weak.

Pterothorax: Medial lobe of metaventrite broadly margined between mesocoxae. Lateral lobes of metaventrite punctate. Metanepisternum reticulate.

Hind wings: Fully developed.

Females. Protibia with apical spur arising from truncate front edge, apical digit absent. Tooth on the underside of protibia usually smaller than in males (except similar in L. cardwellensis ). Inner edge of metatibia not crenulate.

Checklist of species

Lepanus cameroni Gunter & Weir , new species

Lepanus cardwellensis Gunter & Weir , new species

Lepanus globulus ( Macleay, 1887)

Lepanus lemannae Gunter & Weir , new species

Lepanus ustulatus ( Lansberge, 1874)

Key to species of the Lepanus ustulatus species group

1 Protibia with 3 teeth on outer edge ( Fig. 2 A–B); elytral surfaces very finely reticulate, at least in part; generally larger species 4.5–6.5 mm .......................................................................................... 2

– Protibia with 2 teeth on outer edge ( Fig. 2C ); elytral surfaces wholly non reticulate, nitid; generally smaller species 3.5–5.0 mm ................................................................................................. ................................................................................................... 3

2 Pygidium with reticulate depressed central area extending under the transverse sinuate fold ( Fig. 4D ); male metatibia with inner edge more or less roundly expanded apically, bearing a defined brush of fine setae ( Fig. 2F ); aedeagus as in Fig. 5D ; north Queensland from Atherton Tableland to central Queensland south of Mackay. .................................................................................................. Lepanus lemannae Gunter & Weir , new species

– Pygidium with reticulate depressed central area not extending under the transverse sinuate fold, separated from it by an impressed line ( Fig. 4E ); male metatibia with inner edge not expanded apically, without a defined brush of fine setae ( Fig. 2D ); aedeagus as in Fig. 5E ; from central Queensland south of Gladstone to central New South Wales around Taree................................................................................. Lepanus ustulatus ( Lansberge, 1874)

3 Eye canthus not dividing eye, leaving a gap of about 4 facets ( Fig. 2J ); ridge on underside of protibia with coarse crenulations in the middle ( Fig. 2G ); aedeagus as in Fig. 5A ; north Queensland Iron Range................................................................................................... Lepanus cameroni Gunter & Weir , new species

– Eye canthus dividing or nearly dividing eye, leaving a gap of not more than 1 facet ( Fig. 2L ); ridge on underside of protibia more finely crenulated or without crenulations ( Figs. 2 H–I).................................................... 4

4 Ridge on underside of protibia distinctly crenulated in the middle ( Fig. 2H ); head usually finely punctate; posterolateral corners of pronotum distinct ( Fig. 2K ); pygidium with reticulations of central depressed area obvious ( Fig. 4C ); male protibia with apical digit broad ( Fig. 2C ); aedeagus as in Fig. 5C ; north Queensland Wet Tropics from south of Cooktown to Atherton Tableland................................................................... Lepanus globulus (Macleay, 1888)

– Ridge on underside of protibia without crenulations but with a distinct flange in the middle ( Fig. 2I ); head very finely punctate; posterolateral corners of pronotum rounded ( Fig. 2M ); pygidium with reticulations of central depressed area less obvious, area more nitid ( Fig. 4B ); male protibia with apical digit narrower; aedeagus as in Fig. 5B ; north Queensland Cardwell Range area ......................................................... Lepanus cardwellensis Gunter & Weir , new species

Figures

FIGURE 1. Phylogenetic estimate of relationships among described species in the genus Lepanus. Consensus topology generated from Bayesian analysis (BA) with node values for posterior probability BA and bootstrap values of clades also supported in maximum-likelihood analysis. Strongly supported nodes are indicated by coloured circles at base of nodes, while other support values are listed in full. Species groups revised here are highlighted by the grey boxes and IBRA regions for these specimens are also listed following the general locality in bold. Abbreviations for localities are as follows CMC: Central Mackay Coast; CYP: Cape York Peninsula; NNC: NSW North Coast; NSW: New South Wales; NT: Northern Territory; QLD: Queensland; SEQ: South Eastern Queensland; SYB: Sydney Basin; TS: Torres Strait; WA: Western Australia; WET: Wet Tropics.

FIGURE 2. Some diagnostic characters of the Lepanus ustulatus species group. A, Dorsal view of male protibia of Lepanus ustulatus; B, dorsal view of female protibia of Lepanus ustulatus; C, dorsal view of male protibia of Lepanus globulus; D, male metatibia of Lepanus ustulatus; E, female metatibia of Lepanus ustulatus; F, male metatibia of Lepanus lemannae; G, lateral view of male protibia of Lepanus cameroni; H, lateral view of male protibia of Lepanus globulus; I, lateral view of male protibia of Lepanus cardwellensis; J, head of Lepanus cameroni showing eye canthus not dividing the eye; K, posterolateral view of pronotum of Lepanus globulus showing corners distinct; L, head of Lepanus globulus showing eye canthus almost dividing the eye; M, posterolateral view of pronotum of Lepanus cardwellensis showing corners rounded.

FIGURE 4. Pygidial configuration of species within the Lepanus ustulatus species group. A, Lepanus cameroni; B, Lepanus cardwellensis; C, Lepanus globulus; D, Lepanus lemannae; E, Lepanus ustulatus. All specimens in comparative scale. Scale bar 0.5 mm.

FIGURE 5. Left, dorsal and right view of aedeagi of species within the Lepanus ustulatus species group. A, Lepanus cameroni; B, Lepanus cardwellensis; C, Lepanus globulus; D, Lepanus lemannae; E, Lepanus ustulatus. All specimens in comparative scale. Scale bar 0.5 mm.