Lepanus mckenziei 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 : 69-70

Lepanus mckenziei Gunter & Weir , new species

( Figs. 6B , 8H , 11C , 14 )

Type series. Holotype: ♂ “ 15.25S 124.38E, CALM Site 26/1, Augustus Island, Jan 1989, N. McKenzie ” [15°25'S, 124°38'E] /“ Berlesate, ANIC 1270 , closed forest litter” / “ANIC Database No. 25- 060386 ” / “ Lepanus WA4 det. T.A.Weir 2011 ” / “ANIC Image” in WAM. Paratype: CALM Site 10/4, Carson Escarpment, 11 km ESE Theda Homestead, [14°51'S, 126°29'E], i.1989, N. McKenzie (25- 060387 x1 ♀ in ANIC).

Description. Uniform brown in colour. Antennal clubs yellow.

Total length: 1.8–2.0 mm. Holotype measurements: Total length 1.8 mm, elytral width 1.3 mm.

Male: Head: U-shaped between clypeal teeth, which are short and slightly upturned. Basal carina present but interrupted medially. Margin not angulate at clypeogenal suture. Genal angle weakly defined. Dorsal part of eyes narrow in size, separated by interocular space approximately 13 times eye width (26:2); eye canthus nearly dividing eye. Head 1.3 × wider than long (34:26).

Prothorax: Hypomeral surface finely reticulate with light punctation. Basal margin rounded. Hypomeral striae long. Pronotum 1.65 × wider than long (54:33).

Elytra: Surface smooth. Striae 1–5 narrow and double, with very fine punctate edges; striae 6-7 appearing single. All striae on disc equal width. Elytra 1.05 × wider than long (64:60). Elytral flange and groove narrow.

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 minute, appearing simple.

Abdomen: Pygidium with an almost ovoid depression containing a tubercle that is slightly horizontal positioned in upper third; tip of tubercle darker. Upper edge of pygidium concave. Depression occupies more than half of disc and extends under upper edge. Surface slightly reticulate. Abdominal ventrites finely reticulate 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 and mesepimeron smooth. Metanepisternum reticulate.

Female: As per the L. pygmaeus species group.

Etymology. Named for Norm McKenzie, who organized the 1988–1989 CALM survey of the Kimberley rainforests and who collected the only known specimens.

Distribution. Known from only two specimens from the NOK bioregion ( Fig. 14 ). Limited sampling has been conducted in the Kimberley.

Comments. This species has previously been referred to as “ Lepanus WA4” under the informal nomenclature sensu Yeates et al. (2011). Both known specimens were collected from berlesed, closed-forest litter and the only known male specimen is teneral.

Figures

FIGURE 6. Habitus of species within the Lepanus pygmaeus species group. A, Lepanus lingziae; B, Lepanus mckenziei; C, Lepanus menendezae; D, Lepanus pecki; E: Lepanus podocarp; F, Lepanus pungalina. 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 11. Left, dorsal, and right view of aedeagi of species within the Lepanus pygmaeus species group. A, Lepanus lentil; B, Lepanus lingziae; C, Lepanus mckenziei; D, Lepanus menendezae; E, Lepanus pecki. 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.