Lepanus lentil 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 : 68-69

Lepanus lentil Gunter & Weir , new species

( Figs. 4B , 5F , 8F , 11A , 14 )

Type series. Holotype: ♂ “NT: CSIRO, Kakadu Nat. Park , Biodiversity Survey, Feb-Mar 2014, SITE126 B” / “ 12°59'45"S, 132°55'52"E ” / “ANIC Database No. 25-065471” / “ Lepanus NT2 det. T.A.Weir 2014” / “ANIC Image” in ANIC; Paratypes: Northern Territory: 9 km N by E Mudginbarry Homestead, [12°31'00"S, 132°54'00"E], 26.v.1973, M.S. Upton & R.S. McInnes (25-054060 × 1 ♀ in ANIC) ; Kakadu National Park, Site 201, 12.5475°S, 132.929°E, (12°32'51"S, 132°55'44"E,), 2013, S. Oberprieler (25-065527 × 1 ♀ in ANIC) ; Darr River , 31 km NNW Longreach, [23°13'00"S, 144°04'00"E], 22.x.1975, M.S. Upton (25-054059 × 1 ♂ in ANIC) .

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

Total length: 2.4mm. Holotype measurements: Total length 2.4 mm, elytral width 1.6 mm.

Male: Head: U-shaped between clypeal teeth, which are short and slightly upturned. Margin slightly angulate at clypeogenal suture. Genal angle weakly defined. Basal carina present with slight median angle. Dorsal part of eyes moderate, separated by interocular space approximately 12 times eye width (35: 3); eye canthus nearly dividing eye. Head 1.3 × wider than long (46:35).

Prothorax: Hypomeral surface finely reticulate with light punctation. Hypomeral striae about half the length of hypomeron. Pronotum 1.6 × wider than long (78:48).

Elytra: Striae 1–5 narrow and double, with very fine punctate edges. All striae on disc equal width. Elytra 1.2 × wider than long (90:75).

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 a lens shaped depression that is vertical and narrow. Depression occupies less than half size of disc and extends under the concave upper edge of pygidium. No tubercle is present in the depression. Abdominal surface reticulate. Abdominal ventrites finely reticulate right across. Segment 6 punctate.

Pterothorax: Medial lobe of metaventrite very finely punctate and broadly margined between mesocoxae. Lateral lobe of metaventrite punctate with fine reticulations. Meso-metaventral suture very slightly arched. Mesoventrite with slight notch anteriorly. Mesoventrite smooth. mesepimeron very finely reticulate. Metanepisternum reticulate.

Female: As per the L. pygmaeus species group.

Etymology. A noun in apposition referring to the distinct lens-shaped pygidial depression and derived from lenticula (Latin) meaning lens.

Distribution. This species is known from only from three specimens, which may reflect limited sampling in its range and not true rarity ( Fig. 14 ). It has been recorded from Kakadu National Park in the ARP but given the limited sampling in the neighbouring IBRA regions may be more widespread.

Comments. This species has previously been referred to as “ Lepanus NT2” under the informal nomenclature sensu Yeates et al. (2011). All specimens collected to date have been collected in open forest and woodlands.

Figures

FIGURE 4. Some diagnostic characters of the Lepanus pygmaeus species group. A, Head of Lepanus guthrieae featuring medially interrupted basal margin (white arrow) and reticulations on clypeal area only (black arrow); B, head of Lepanus lentil featuring angulate and complete basal margin (white arrow); C, pterothorax of Lepanus andersonorum showing fine, short carina extending backwards from the meso-metaventral suture (white arrow); D, posterior aspect of metatibia of Lepanus pecki; E, anterior aspect of metatibia of Lepanus pecki; F, anterior aspect of metatibia of Lepanus guthrieae; G, female protibia of Lepanus pygmaeus; H, male protibia of Lepanus pygmaeus; I, female protibia of Lepanus pecki; J, male protibia of Lepanus pecki; K, male protibia of Lepanus crenidens; L, male protibia of Lepanus pungalina; M, inner laterodorsal aspect male protibia of Lepanus pungalina showing bent apical digit (black arrow).

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 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.