Maurodus, 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 : 26-33

Maurodus , gen. nov.

( Figs 4–9 )

Type species: Caccomolpus ornatus Broun, 1910

Diagnosis. Body length greater than 3.0 mm and less than 8.0 mm; elliptical and moderately convex; colour uniform to tricoloured, metallic sheen absent. Antennae weakly clavate or subfilliform. Procoxal cavities externally open. Hindwings absent. Anterior edge of metaventrite straight; metaventral lines parallel and not extending to middle of ventrite. First abdominal ventrite with subcoxal lines parallel to coxal cavity and not extending to middle of ventrite.

Description. Length 3.2–5.1 mm. Body elliptical and moderately convex. Colour of body typically bicoloured to tricoloured, red, orange, black or white, rarely uiform, lacking metallic sheen.

Head not forming a short muzzle with genae extending a short distance beyond level of antennal and maxillary insertions, scarcely visible from above with mouthparts directed anteriorly, wide vertex or frons, nearly flat to feebly convex; postantennal calli weakly developed, but lacking pale areas; antennal groove present or absent. Eyes relatively well-developed, not protuberant, coarsely facetted and consisting of over 30 ommatidia; inner margin of eye without a small seta. Antennae long and weakly clavate, scape short and somewhat elliptic, shorter than the A2+3 combined, last four antennomeres forming a weak club, reaching beyond the hind margin of the pronotum; eye not contacting insertion, with distance between insertion and margin of eye less than diameter of insertion, distance between insertions about 6 times length of the scape. Clypeus transverse to trapezoidal, anterior margin usually straight; frontoclypeal suture usually present; lateral and medial postclypeal lines present or absent and deeply to weakly impressed. Labrum somewhat rectangular and distinctly transverse, anterior margin weakly emarginated and sides rounded, surface with 3 elongate setae per side, anterior margin at middle lacking distinct setal fringe, tormae long and thin, about 2 times longer than labral plate. Mandible with terebral edge simple. Maxillary palpus relatively short, palpomere 1 about as long as wide, palpomere 2 transverse and shorter than wide, palpomere 3 about 2 times longer than wide, greater in length than palpomere 2, conical to weakly acute. Labium with relatively wide ligula, greater or equal in width to the lengths of palpomeres 1 and 2 combined, apex not or very weakly divided at apex, palpal insertions separated by at least the width of the basal palpomere, palpi relatively short, palpomere 1 shorter than long, palpomere 2 as long as wide, palpomere 3 twice longer than wide with narrowed and truncated apex. Mentum rectangular and transverse, width of mentum equal to or shorter than the length of labial palpomere 3. Intermaxillary process short and not extending anteriorly far beyond maxillary insertions, delimited behind by a ridge or a bead.

Pronotum transverse and convex, with a bead along anterior and lateral margins; posterior edge as wide as or slightly narrower than base of elytra; anterior margin weakly emarginated, anterior angles weakly projecting and rounded; sides distinctly converging anteriad and straight or curved, posterior margin weakly convex, sinuate or straight; posterior angles acute; disc moderately convex without sublateral groove, trichobothria absent, punction not uniform and generally coarse and more dense at middle of posterior margin; lateral carinae complete. Prosternum not vaulted at middle, without transverse notches in front of coxal cavities; prosternal lines present and usually parallel, convergent anteriorly in some species or rarely polymorphic and extending forward almost reaching anterior edge of sternite; prosternal process broad, short and extending a short distance behind procoxae, expanded laterally behind coxae but not contacting the hypomeral process; posterior margin straight, procoxal cavities partially externally closed. Notopleural suture distinct. Scutellary shield visible and relatively small, triangular with rounded or subacute apex. Elytra strongly convex, well-developed humeral calli absent but a weak humeral impression may be present; midbasal stria or impression present; surface smooth, punctures weakly impressed and striate, epipleura wide and well developed, visible in lateral view, apex without ctenidium. Hind wings absent. Mesoventrite mostly hidden in ventral view, posterior portion between mesocoxae visible as a narrow strip; mesal part of mesoventrite with vertical surface confluent with prepectus. Meso- and metacoxae widely separated. Metaventrite shorter than abdominal ventrite 1 at midline, mesocoxal process very short and broad with a straight anterior margin, metaventral lines parallel, discrimen present but weakly impressed, transverse metaventral (metakatepisternal) suture present does not cross the midline or weakly impressed. Metendosternite lacking stalk and laminae, widely spaced lateral arms with subapical anterior tendons. Legs with tibiae flattened in cross section, meso- and metatibiae clubbed with abrupt constriction at basal 1/3 or approximately at midlength with lateral edge sinuate (sometimes the protibiae, and weakly sinuate in M. impressus and M. maculatus ), apically setose; tarsomeres 5-5-5 and variable, tarsomere 1 nearly as long as T2 or longer (lengthened or enlarged or not in males), 1.5 times longer than wide or equilateral, T2 transverse and wider than long and wider or narrower than T3, T3 about as wide as long or slightly transverse and deeply incised (bilobed), tarsomere 4 minute, T5 about twice as long as T3, claws simple.

Abdominal ventrite 1 long, but shorter than ventrites 2–5 combined, with a broad metacoxal process that is wider than long and with a curved apical margin, ventrites 2–4 equal in length and much shorter than ventrite 1, ventrite 5 longer than ventrites 3 and 4 combined with rounded posterior margin; first abdominal ventrite with subcoxal lines parallel to coxal cavity that do not extend to middle of ventrite. Aedeagus variable, curved to weakly curved or straight in lateral view and rounded to weakly laterally compressed in cross section; apex in dorsal view acute to rounded or apiculate; flagellum present or absent. Ovipositor with coxite 2 times longer than wide, stylus apically inserted and about 1/6 the length of coxite. Spermatheca curved, C- or V- shaped, collum absent with spermathecal duct inserted onto base, spermathecal gland absent or very weakly sclerotised.

Comments. This endemic genus has 11 species, including one transferred here from Aphilon ( A. impressus Broun ) and four transferred here from Caccomolpus ( C. cinctiger Broun, C. maculatus Broun, C. ornatus Broun , and C. plagiatus Sharp ). All are ground-dwelling, collected mostly by sifting leaf litter, and are flightless with relatively short metaventrites. Species are similar to Caccomolpus but can be distinguished by by their less rounded shape, parallel-sided metacoxal lines, and gaudy colouration. Many species are rare, some decribed only from singletons ( M. arcus , M. lepidus , M. nunni , and M. owenensis ).

Etymology. Patrynomic for Mauro Daccordi for his lifelong commitment to the study of Chrysomelinae (masculine).

Included species. Maurodus arcus sp. nov., M. cinctiger Broun , comb nov. (from Caccomolpus ), M. impressus Broun , comb nov. (from Aphilon ), M. lepidus sp. nov., M. maculatus Broun , comb nov. (from Caccomolpus ), M. nunni sp. nov., M. occiduus sp. nov., M. ornatus (Broun) , comb nov. (from Caccomolpus ), M. owenensis sp. nov., M. plagiatus Sharp , comb nov. (from Caccomolpus ), M. supernus sp. nov.

Distribution. North Island, South Island.

Figures

FIGURES 4A–F. Habitus of Maurodus spp.; A, Maurodus arcus, dorsal; B, Maurodus arcus, lateral; C, Maurodus cinctiger, dorsal, length 4.1 mm; D, Maurodus cinctiger, lateral, length 4.2 mm; E, Maurodus cinctiger, dorsal; F, Maurodus cinctiger, ventral.

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 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 7A–I. Habitus and structures of Maurodus spp.; A, Maurodus ornatus, dorsal; B, Maurodus ornatus, lateral, length 3.8 mm; C, Maurodus ornatus, dorsal, length 3.9 mm; D, Maurodus ornatus, lateral; E, Maurodus ornatus, dorsal view of head and pronotum; F, Maurodus cinctiger, dorsal view of adeagus; G, Maurodus cinctiger, lateral view of adeagus; H, Maurodus ornatus, dorsal view of adeagus; I, Maurodus ornatus, lateral view of adeagus.

FIGURES 8A–F. Habitus of Maurodus spp.; A, Maurodus owenensis, dorsal; B, Maurodus owenensis, ventral; C, Maurodus plagiatus, dorsal; D, Maurodus plagiatus, ventral; E, Maurodus plagiatus, lateral; F, Maurodus plagiatus, dorsal holotype.

FIGURES 9A–D. Habitus of Maurodus supernus; A, dorsal; B, ventral; C, lateral; D, ventral.