Lepanus sauroni 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 : 75-77

Lepanus sauroni Gunter & Weir , new species

( Figs. 7B , 9E , 12D , 18)

Type series. Holotype: ♂ “ AUSTRALIA: N.T. Humpty Doo , 6 km E, 9. ii–4. iii.1987, R.I. Storey ” [12°37'S, 131°18'E] / “ANIC database No. 25-065528” / “ Lepanus NT4 det. T.A.Weir 2018 ”/ T244826” in QM. Paratypes: Humpty Doo , 6 km E, [12°37'S, 131°18'E], 9.ii–4.iii.1987, R.I. Storey (25- 060380 x 4 in ANIC 2 × ♂, 2 × ♀, 25- 0 58573 x 2 in QDPC 2 × ♀); Darwin CSIRO, McMillans Road , [12°24'42"S, 130°55'19"E], 25.xii.1993 – 10.i.1994, S.B. & J. Peck ( CMNEN-00030261 in CMNC ♀); Darwin CSIRO, McMillans Road , [12°24'42"S, 130°55'19"E], 1–25.xii.1993, S.B. & J. Peck ( CMNEN-00030264 ♀, 0 0 0 30270 ♀, 0 0 0 30280 ♀ in CMNC; 0 0 0 30412 ♂ in ANIC); 11.5 km E of Humpty Doo, 12°35'46"S, 131°12'22"E, 50 m, 10–11.ii.2015, G.B. Monteith (25-065478 x 1 in ANIC ♀ also as COL3132); Central Hill , 12 km N, [13°51'S, 136°38'E], 30 m, 19–20.ii.2005, D.J. Cook (25- 0 65472 x 6 in QM also as T154889–T154894 2 × ♂, 3 × ♀, 1 × sex undetermined, 25-065472 × 1 in ANIC ♂); 15 km along Beagle Bay Road, 17°45'22"S, 122°16'48"E, 12 m, 13–14.ii.2015, G.B. Monteith (25- 063083 x1 ♀ in ANIC); Beagle Bay Road turnoff, 17°53'10"S, 122°16'37"E, 23 m, 13–14.ii.2015, G.B. Monteith (25- 063082 x 1 in WAM ♀) ( COL3036 ); Gantheaume Point Road, 17°57'50"S, 122°12'14"E, 12 m, 12–13.ii.2015, G.B. Monteith (25- 063081 x 2 in WAM 1 ♂, 1♀) ( COL3039 ); Gubinge Road end, Broome, 17°58'30"S, 122°12'36"E, 17 m, 12– 13.ii.2015, G.B. Monteith (25- 063079 2 × ♂, 1♀, 25- 063080 x1 ♀ in ANIC) ( COL3037 , COL3038 ); 14 km along Beagle Bay Road, 17°46'08"S, 122°16'55"E, 20 m, 13–14.ii.2015, G.B. Monteith (25-065477 x1 ♂ in QM also as COL3133).

Description. Bicoloured with head and pronotum dark brown and rest of the body light brown. Antennal clubs grey.

Total length: 1.8–2.3 mm. Holotype measurements: Total length 2.0 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 and medially interrupted. Dorsal part of eyes narrow in size, separated by interocular space approximately 20 times eye width (30–32: 1.5); eye canthus not dividing the eye. Head 1.35 × wider than long (39:29).

Prothorax: Hypomeral surface very finely reticulate with light punctation. Hypomeral striae about half length of the hypomeron. Pronotum 1.7 × wider than long (68:40).

Elytra: Surface smooth. Striae 1–3 narrow and appearing double, with very fine punctate edges; striae 4–7 appearing single. Elytra 1.15 × wider than long (74:63).

Legs: Front edge of protibiae deeply angulate; apical digit somewhat elongate and sharp; 3 teeth on outer edge. Inner edge of metatibiae almost straight. Metatarsi with 2nd tarsomere subequal to the 5th. Tarsal claws intermediate and toothed.

Abdomen: Pygidium with tear-drop shape depression containing a tubercle that is a vertical raised line. Depression occupies half size of disc and extends under the virtually straight upper edge of pygidium. Abdominal surface reticulate right across. Segment 6 finely 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 and mesepimeron smooth. Metanepisternum reticulate.

Female: Pygidium with oval-shape depression containing a tubercle that is more rounded but still elongate. Abdominal ventrite 6 gibbous, otherwise as for the L. pygmaeus species group.

Etymology. This species is named sauroni for the distinctive pygidial depression with elongate turbercle that resembles the Eye of Sauron from Peter Jackson’s film adaptation of The Lord of the Rings.

Distribution. Known only from 27 specimens from coastal open forests in Western Australia and the Northern Territory including Groote Eylandt within the IBRA regions DAL, DAC, and ARC ( Fig. 17 ). Our BIOCLIM model predicted L. sauroni has a widespread distribution occurring in all of the most northerly IBRA regions.

Comments. This species has previously been referred to as “ Lepanus NT4” under the informal nomenclature sensu Yeates et al. (2011). A specimen collected near Broome, Western Australia (Gantheaume Point Road) was sequenced in the study of Gunter et al. (2018) and is designated as a paratype here (ANIC25- 063081). It was recovered as a member of the monsoonal clade of Lepanus , which contains species in the L. pygmaeus species group. Lepanus sauroni has been collected in both dung or mushroom baited pitfall traps from open forest, sandy heath, and sandy open forests.

Figures

FIGURE 7. Habitus of species within the Lepanus pygmaeus species group. A, Lepanus pygmaeus; B, Lepanus sauroni; C, Lepanus tozerensis. All specimens in comparative scale. Scale bar 1 mm.

FIGURE 9. Pygidial configuration of species within the Lepanus pygmaeus species group. A, Lepanus pecki; B, Lepanus podocarp; C: Lepanus pungalina; D, Lepanus pygmaeus; E, Lepanus sauroni; F, Lepanus tozerensis. All specimens in comparative scale. Scale bar 0.2 mm.

FIGURE 12. Left, dorsal, and right view of aedeagi of species within the Lepanus pygmaeus species group. A, Lepanus podocarp; B, Lepanus pungalina; C, Lepanus pygmaeus; D, Lepanus sauroni; E: Lepanus tozerensis. 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 17. Map of known records of Lepanus sauroni including predicted distribution overlaid with predicted distribution boundary of L. pygmaeus (dashed line) taken from Fig. 13 map.