Maurodus occiduus, Leschen & Reid & Nadein, 2020

Leschen, Richard A. B., Reid, Chris A. M. & Nadein, Konstantin S., 2020, Generic Review of New Zealand Chrysomelinae (Coleoptera: Chrysomelidae), Zootaxa 4740 (1), pp. 1-66 : 42

Maurodus occiduus , sp. nov.

( Figs 6E,F , 12E,F ; map Fig. 20A )

Diagnosis. Body broadly oval and bicoloured; pronotum bicoloured with a distinct spot in the anterolateral portion of the disc. Antennal groove weakly indicated; inner ridge weak or absent and glabrous area present or absent. Prosternal lines in front of procoxae parallel. Elytra with midbasal stria or puncture present; maculae broad with outer edges sinuate and contacting broadly at midline; microsculpture predent or absent. Ventrites dark-coloured and infuscate, with hypomera and epipleura uniformly pale-coloured; male ventrite 5 not vaulted at middle. Legs unicoloured yellow to weakly infuscate; tarsomere 1 of male greatly enlarged.

Description. Length 3.5–4.4 mm (greatest depth 1.70–2.10 mm). Body broadly oval and bicoloured with head, most of the pronotum, elytral macula, and middle portions of the ventral surfaces black; anterior portion of clypeus, margins of pronotum and elytra, mouthparts, antennae, hypomera, and epipleura yellow to pale-coloured; a distinct spot is present in the anterolateral portion of the pronotal disc; elytral maculae sinuate along lateral edge; femora and tibiae unicoloured yellow to weakly infuscate with femora dark at base. Microsculpture distinct to absent on pronotum and elytra. Clypeus moderately to very finely punctate, more or less trapezoidal, anterior margin straight; frontoclypeal suture absent or present but not strongly impressed and not meeting at midline; lateral postclypeal lines present medial line absent; vertex moderately to very finely punctate. Ratio of antennomere lengths: 1.3/1.0/1.4/1.2/1.2/1.0/1.2/1.2/1.4/1.4/1.9. Antennal groove weakly indicated; inner ridge weak or absent and glabrous area present or absent. Pronotum transverse (2.10–2.17 x wider than long), lateral margins at base subparallel-sided and sides weakly converging anteriorly, not strongly convex; punctures non-uniform, more or less coarse at base and progressively diffuse anteriorly, those at base usually stronger than elsewhere on the dorsum, or about as impressed on some specimens with the posterolateral striae punctate. Prosternal lines or carinae in front of procoxae parallel; intercarinal space weakly convex. Elytra widest at middle with a weakly convex outline (1.03–1.04x the greatest elytral width), 2.50–2.67 x longer than pronotal length and broad; punctation very weakly striate, not impressed towards midline, but sometimes forming punctate striae postero-apically or forming distinct grooves; midbasal stria or puncture present and may be weakly developed, broad and shallow. Male ventrite 5 not vaulted at middle. Median lobe of aedeagus in lateral view narrowing at posterior ¼ to apex and acute; in dorsal view, weakly parallel-sided and broad subrounded apex; flagellum present. Tarsomere 1 of male greatly enlarged.

Comments. Maurodus occiduus can be distinguished from most species of the genus by the bicoloured pronotum with a distinct spot in the anterolateral portion of the disc. The lack of a vaulted abdominal ventrite 5 in the male differentiates this species from the similar-looking M. maculatus . There is some variation on the punctuation and development of the antennal groove, but the groove is not as well developed as other members of the genus, and generally does not have a well-developed inner carina or ridge: this variation is present among specimens in the Haast area.

Distribution. South Island: WD, OL, FD.

Etymology. The specific epithet is derived from the Latin word occiduus meaning west, referring to its distribution in the South Island.

Type material examined. Holotype ( AMNZ): male [mounted on card], “Waiho Gorge S Westland 15-1-25 [hand written on bottom card by? C.E. Clarke] // C.E. Clarke Collection ” . Paratypes (25): South Island. WD/OL: Haast Pass, 44.078195S, 169.386185E, 10.04.1979 [J. Nunn] (1, NZAC) . WD: NC, Arthurs Pass , 860m, 14–23. iv. 1984, J.W. Early, Yellow pan trap in moss in Nothofagus solandri forest (1, LUNZ) ; 4 km N of Haast Pass, Fantail Falls 450m, 44.078195S, 169.386185E, leaf litter, 04.01.1984, P.M. Hammond (1, BMNH) ; 6 km SW Mahitahi, 43.662571S, 169.577551E, swamp forest, 05.02.1984, P.M. Hammond (1, BMNH); S Westland, Waiho R, 43.422503S, 170.170088E, 12.01.1925, C.E. Clarke Collection (1, AMNZ) ; same except 13.01.1925 (1, BMNH) ; same except 14.01.1925 (2, BMNH) ; same except C.E. Clarke, G. V. Hudson (1, BMNH) ; same except 16.01.1925 C.E. Clarke (1, BMNH) ; S Westland, Waiho Gorge , 43.422503S, 170.170088E, 12.01.1925, C.E. Clarke Collection (1, AMNZ) ; same except 14.01.1925 (8, AMNZ) ; same except 16.01.1925 (1, AMNZ) ; Waiho R. V, 42.953168S, 170.829454E, forest litter, 06.02.1984, P.M. Hammond (1, BMNH) ; Mt Greenland, 42.953168S, 170.829454E, 08.01.1943, C.E. Clarke, C.E. Clarke Collection (1, BMNH; 1, AMNZ) ; same except 09.01.1943 (1, BMNH; 2, AMNZ) .

Figures

FIGURES 6A–F. Habitus and structures of Maurodus spp.; A, Maurodus nunni, dorsal; B, Maurodus nunni, dorsal; C, Maurodus nunni, lateral; D, Maurodus ornatus, anterior view of head; E, Maurodus occiduus, dorsal; F, Maurodus occiduus, lateral.

FIGURES 12A–N. Habitus and genitalia; A, Nanomela sp., dorsal, scale = 1 mm; B, Nanomela tiniheke, dorsal, scale = 1 mm; C, Maurodus maculatus, aedeagus, dorsal view; D, Maurodus maculatus, aedeagus, lateral view; E, Maurodus occiduus, aedeagus, dorsal view; F, Maurodus occiduus, aedeagus, lateral view; G, Maurodus nunni, aedeagus, dorsal view; H, Maurodus nunni, aedeagus, lateral view; I, Maurodus supernus, aedeagus, dorsal view; J, Maurodus supernus, aedeagus, lateral view; K, Zeaphilon marskeae, aedeagus, dorsal view; L, Zeaphilon marskeae, aedeagus, lateral view; M, Zeaphilon mirandum, aedeagus, dorsal view; N, Zeaphilon mirandum, aedeagus, lateral view.

FIGURES 20A–B. South Island with subantarctic Snares Island (insert).