Zenascus aurum, Grzymala & Leschen, 2020

Grzymala, Traci L. & Leschen, Richard A. B., 2020, Sexual Dimorphism of New Zealand Puppet Beetles (Aderidae, Coleoptera, Tenebrionoidea): Systematic Revision, Description of Three New Genera, and Phylogeny for Zenascus, gen. n., Zootaxa 4889 (1), pp. 1-59 : 30-35

Zenascus aurum sp. n.

Figs 11C , 14C , 18C , 20C , 21C , 23C , 24A , 27A

Etymology. The specific epithet is in reference to the gift of gold brought by one of the three kings during the Epiphany because of the geographic restriction of this species to the Three Kings Islands. This is additionally a reference to the distinctive golden pubescence of this species, which serves to separate it from the similar Z. obscurus . The name is formed from the Latin aurum (gold).

Diagnosis. This species is distinguished from congeners by the biseriate pubescence, the short and narrow antennomere 3, and the elytra testaceous except for a thick oblique brunneous stripe occupying ¼ of the elytral disc. Zenascus aurum is most similar in general habitus appearance to Zenascus obscurus . Zenascus aurum is distinguished by the testaceous elytral disc with a small brunneous area, whereas Z. obscurus is characterized by an entirely brunneous elytral disc. Additionally, Zenascus aurum has also only been collected from Three Kings Island while Z. obscurus has been collected from the North and South Islands of New Zealand.

Description. Length 1.84 mm. Head, antennal scape, antennomeres 4–11, pronotum, elytra, legs, and venter brunneous to fuscous. Dorsal integument matte, vestiture biseriate, one decumbent, thin, long seta arising anterad of each puncture, length about 3.5× puncture length, with 4–5 decumbent, thin, shorter setae between each pair of punctures, length about 2/3× primary seta. Ventral vestiture biseriate, similar to dorsum. Head, HW 0.53 mm, HL 0.23 mm, lacking impression between antennal ridge and vertex absent and deep, elongate punctures present on vertex absent, only micropunctures present. Antennae with distance between insertions wide, approximately equal to diameter of three antennal insertions; length reaching past basal 2/3 of elytra when extended backward; scape rounded, slightly longer than wide, subequal in width basally and apically; pedicel subglobular; antennomere 3 subequal in length to pedicel, slightly reduced in width, width slightly expanding apically; antennomere 4 longer than 3 and slightly greater in width; antennomeres 4–8 subequal in length and width, each slightly expanded apically; antennomeres 4–9 subserrate, serration produced anteriorly; antennomeres 9 and 10 decreasing in length, subequal in width; antennomere 11 elongate; antennomeres 3–11 covered in moderately dense, suberect pubescence, without additional pilosity. Pronotum, PW 0.39 mm, PL 0.38 mm, subquadrate, width subequal to slightly greater than length, width 1.03× length; pronotal width 0.56× elytral width, pronotal width 0.74× head width; sides slightly sinuate; disc with two slightly impressed basal fovea, with transverse sulcus just anterad of center; deep elongate punctures present, approximately evenly spaced, separated by an average of one punctural width and absent from midline posteriorly to center. Elytra 2.12× longer than wide and 3.84× longer than pronotal length, EW 0.69 mm, EL 1.46 mm; disc with moderately impressed oblique subscutellar depression; elongate punctures present, separated by an average of two punctural lengths. Proleg with tarsomeres 1 and 2 subequal in length, tarsomere 1 with ventral short, stout spine; ventral surface of tarsomeres 2 and 3 with adhesive setae. Midleg with tibia gently curved inward from base to apex. Hindleg without distinct, deep punctures along posterior margin of coxa; femur with distinctly thickened setae on postero-ventral face, overlying slight excavation along entire length of femur, apico-ventral impression absent; tibia gradually expanded in width from base to apex, apex inner face triangular and densely pubescent. Abdomen with lateral and medial lengths of ventrite 2 subequal; deep punctures confined to abdominal process and across entirety of ventrites 1 and 2 except for distinct line indicating sutural separation; deep punctures confined medially on ventrites 3 and 4; ventrite 5 with only small, shallow micropunctures present, without medial impression. Phallobase broadly rounded anteriorly, delimited from apicale laterally and medially with distinct sclerotization; apicale posteriorly narrowly acute, accessory lobes present, with four setae, one thin, elongate seta and two thin, short setae at apex, one thin, short seta basad to these; penis with anterior struts elongate, but not extending past phallobase.

Females. Length 1.78–2.11 mm, HW 0.53–0.56 mm, HL 0.20–0.24 mm, PW 0.38–0.47 mm, PL 0.35–0.41 mm, EW 0.66–0.98 mm, EL 1.43–1.67 mm. Antenna with scape rounded, slightly longer than wide, subequal in width basally and apically; pedicel subglobular; antennomere 3 subequal in length to pedicel, slightly reduced in width; antennomere 4 wider and longer than antennomere 3; antennomeres 4–6 subequal in length and width; antennomere 7 subequal in width and slightly shorter than antennomere 6; antennomeres 7–10 subequal in length and width; antennomere 11 slightly wider and longer than antennomere 10.

Natural history. This species is known only from the Three Kings Islands and has been collected primarily from beating plants, specifically Phormium tenax J. R. Forst & G. Forst , but has also been found under the bark of Metrosideros excelsa Sol. ex Gaertn. and by sifting litter.

Distribution. Offshore island : Three Kings Island (TH).

Type material examined. Holotype, Female ( NZAC): “Castaway / Camp // Three Kings Is / Great I. Nov. 70 / NZ. Ent.Div.Exp. // G. Kuschel // ex. Phormium / tenax litter” . Paratypes (8): Offshore island . TH: Great I, 30/11/1983, beating plants, C.F. Butcher (3, NZAC) ; Great I, Castaway Camp , 11/1970, ex. Phormium tenax, G. Kuschel (1, NZAC) ; same, but no host data (2, NZAC) ; Southeast Bay , 12/02/1983, under bark of Metrosideros excelsa (1, NZAC) ; South West Island , 11/1970, litter, G. Ramsay (1, NZAC) .

Figures

FIGURES 11A–E. Dorsal habitus images. (A) Zenascus coloratus (Broun), male; (B) Zenascus obscurus (Broun), male; (C) Zenascus aurum, sp. n., female; (D) Zenascus nitidus (Broun), male; (E) Zenascus elenae, sp. n., male. Scale bars = 1.0 mm.

FIGURES 14A–J. Antennal illustrations for Zenascus species, male on left, female on right.(A) Z. coloratus; (B) Z. obscurus; (C) Z. aurum, sp. n.; (D) Z. nitidus; (E) Z. elenae, sp. n.; (F) Z. antennalis; (G) Z. xenarthrus; (H) Z. roberti, sp. n.; (I) Z. luniger; (J) Z. incensum, sp. n. Scale bar = 0.1 mm.

FIGURES 18A–E. Scanning electron microscope images, Zenascus species, elytron, dorsal view. (A) Z. coloratus; (B) Z. obscurus; (C) Z. aurum, sp. n.; (D) Z. nitidus; (E) Z. elenae, sp. n. Scale bars = 10μm.

FIGURES 20A–J. Scanning electron microscope images, ventral view of metafemora for Zenascus species. (A) Z. coloratus, male; (B) Z. obscurus, male; (C) Z. aurum, sp. n., male; (D) Z. nitidus, female; (E) Z. elenae, sp. n., male; (F) Z. antennalis, female; (G) Z. xenarthrus, male; (H) Z. roberti, sp. n., male; (I) Z. luniger, male; (J) Z. incensum, sp. n., male. Scale bars = 60μm.

FIGURES 21A–E. Abdominal ventrite illustrations for Zenascus species showing generalized punctation pattern. (A) Z. coloratus (Broun), male; (B) Z. obscurus (Broun), male; (C) Z. aurum, sp. n., male; (D) Z. nitidus (Broun), male; (E) Z. elenae, sp. n., male.

FIGURES 23A–J. Male genitalia illustrations for Zenascus species. (A) Z. coloratus; (B) Z. obscurus; (C) Z. aurum, sp. n.; (D) Z. nitidus; (E) Z. elenae, sp. n.; (F) Z. antennalis; (G) Z. xenarthrus; (H) Z. roberti, sp. n.; (I) Z. luniger; (J) Z. incensum, sp. n.

FIGURES 24A–F. Scanning electron micrographs of gland pores on metafemur of Zenascus spp. (A) Z. aurum, sp. n.; (B) Z. antennalis; (C) Z. xenarthrus; (D) Z. roberti, sp. n.; (E) Z. luniger; (F) Z. incensum, sp. n. Scale bars = 2μm.

FIGURES 27A–D. Distribution maps. (A) Zenascus aurum, sp. n., Zenascus incensum, sp. n., and Zenascus xenarthrus, (B) Zenascus coloratus, (C) Zenascus elenae, sp. n. and (D) Zenascus luniger.