Maurodus impressus ( Broun, 1914 ) 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 : 36

Maurodus impressus ( Broun, 1914) , comb. nov.

( Fig. 5A , 13C; map Fig. 19A )

Aphilon impressa Broun, 1914:258 . Type locality: McClennan’s Bush, near Methven.

Diagnosis. Body oval and unicoloured.Antennal groove not demarked by ridges. Prosternal lines in front of procoxae parallel. Elytra with midbasal puncture weakly indicated; microsculpture present. Ventral portions dark-coloured; male ventrite 5 not vaulted at middle. Legs unicoloured.

Description. Length 3.0– 3.2 mm (greatest depth 1.60 mm). Body oval and almost entirely black; antennae, mouthparts, and legs yellow to pale-coloured. Microsculpture distinct, present and strongly impressed on elytra. Clypeus finely punctate, semicircular, nearly as long as wide, anterior margin weakly curved; frontoclypeal suture present with lateral postclypeal lines present, medial line absent; vertex weakly punctate, less coarse than clypeal punctures. Ratio of antennomere lengths: 1.1/0.7/0.8/0.8/0.7/0.7/0.8/0.9/0.9/0.9/1.5. Antennal groove not demarcated by ridges. Pronotum transverse (2.00–2.43 x wider than long), lateral margins at base not subparallel-sided and sides converging anteriorly; punctures not uniform, coarse at base and progressively diffuse anteriorly and weak, those at base stronger than elsewhere on the dorsum. Prosternal lines or carinae in front of procoxae parallel; intercarinal space convex. Elytra widest at middle and moderately convex (0.90–1.00 x the greatest elytral width), 2.55–3.28 x longer than pronotal length and broad; punctation very weakly striate, not impressed towards midline; midbasal puncture weakly indicated. Male ventrite 5 not vaulted at middle. Spermatheca annulate, open and Lshaped and weakly narrowed basally without a distinct basal gland; collum absent.

Comments. Broun based the description on a single specimen which we located in the BMNH and confirmed as the holotype. Under direct light this specimen is red brown in colour with a darker border, a discolouration that may have been the result from dissection or it being slightly teneral; a variant pinned next to it in the Broun collection and from Mt Hutt is female and unicoloured. Broun mentioned that “it is the first of this genus that has been secured in the South Island” and differs “from all the species of about equal bulk this is distinguishable by the thoracic impressions and apparently smooth elytra.” This species is transferred from Aphilon to Maurodus because the abdominal ventrite has the subcoxal lines parallel to coxal cavity forming a narrow bead. It can be distinguished from all other members of Maurodus from its unicoloured body.

Type examined. Holotype ( BMNH): re-pointed with cleared abdomen and female terminalia in media on separate acetate card, “3666 [in Broun’s hand] // New Zealand. [red underline] Broun Coll. Brit. Mus. 1922-482. // McClellans. 25.3.1912. [in Broun’s hand] // Aphilon impressa [in Broun’s hand] // Aphilon impressum Broun [handwritten] det. M. Daccordi [printed] 1987 [in Daccordi’s hand]”.

Additional material examined: South Island. MC: Mt Hutt , 43.586446S, 171.524205E, 05.01.1913, 3666 Broun Collection (1, BMNH).

Figures

FIGURES 5A–H. Habiti and structures of Maurodus spp.; A, Maurodus impressus, dorsal view of holotype, length 3.1 mm; B, Maurodus cinctiger, frontal view of head; C, Maurodus cinctiger, dorsal view of head and pronotum; D, Maurodus lepidus, dorsal; E, Maurodus lepidus, dorsal; F, Maurodus maculatus, dorsal; G, Maurodus maculatus, lateral; H, Maurodus maculatus, oblique lateral.

FIGURES 19A–B. A and B, South Island.