Zenascus obscurus ( Broun, 1893 ) 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 : 44-47

Zenascus obscurus ( Broun, 1893) , comb. n.

Figs 11B , 13 A–13H, 14B, 16A, 16B, 18B, 20B, 21B, 23B, 28B

Xylophilus obscurus Broun, 1893: 1164–1165 ; Pic, 1894: 430; Hudson, 1934: 204.

Hylophilus brouni ; Pic, 1901: 67 [unnecessary emendation]; Pic, 1902: 7; Pic, 1905: 231; Pic, 1910: 7.

Hylophilus obscurus ; Pic, 1905: 217.

Xylophilus brouni ; Maddison, 2010: 428.

Xylophilus pictipes Broun, 1893: 1164 ; Pic, 1894: 431; Hudson, 1934: 204; Maddison, 2010: 428. Syn. n.

Hylophilus pictipes ; Pic, 1902: 10; Pic, 1905: 216, 232; Pic, 1910: 14.

Diagnosis. This species is distinguished from congeners by the biseriate pubescence, the short and thin antennomere 3, brunneous elytra, and the unmodified male antennae. Zenascus obscurus is most similar in general habitus appearance to Zenascus coloratus and Zenascus aurum, Zenascus obscurus can be separated from Z. coloratus by the entirely brunneous elytra (though a few specimens have very slighty lightened elytral humeri) and the brunneous coloration of the prolegs and midlegs. Zenascus obscurus is distinguished from Z. aurum by the overall brunneous elytral integument as opposed to testaceous with an oblique brunneous band. Zenascus aurum has also only been collected from the Three Kings Islands whereas Z. obscurus is widely distributed across both the North and South Islands but is absent from the Three Kings Islands.

Description. Length 1.79–2.23 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× puncture length, with 4–5 additional decumbent, thin, shorter setae between each pair of punctures, length about 2/3× primary seta. Ventral vestiture similar to dorsum, biseriate. Head, HW 0.51–0.58 mm, HL 0.17–0.22 mm, impression between antennal ridge and vertex absent. Antennae with distance between antennal insertions wide, approximately equal to diameter of five antennal insertions; length reaching past basal ½ 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 0.44–0.52 mm, PL 0.38–0.47 mm, subquadrate, width subequal to slightly greater than length, width 1.11–1.17× length; pronotal width 0.52–0.69× elytral width, pronotal width 0.86–0.91× head width; sides slightly sinuate; disc with two deeply impressed basal fovea, transverse sulcus present just anterad of center; punctation consisting of deep elongate punctures, approximately evenly spaced, separated by an average of one punctural width, absent from midline posterior to center. Elytra 1.76–2.24× longer than wide and 3.71–4.39× longer than pronotal length, EW 0.63–1.0 mm, EL 1.41–1.80 mm; moderately impressed oblique subscutellar depression present; punctation consisting of elongate punctures, 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,entirety of ventrite 3, and confined basally to ventrite 4; ventrite 5 with small, shallow micropunctures, medial impression absent. Phallobase broadly rounded anteriorly, laterally and medially delimited from apicale, 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. Antennae with scape rounded, slightly longer than wide, subequal in width basally and apically; pedicel subglobular; antennomere 3 subequal in length and width to pedicel; antennomere 4 slightly wider than antennomere 3; antennomere 5 slightly wider than antennomere 4; antennomeres 5–7 subequal in length and width; antennomere 8 slightly shorter than antennomere 7; antennomere 8–10 subequal in length and width; antennomere 11 subequal in width and about 2× longer than antennomere 10.

Remarks. This is Broun species 2066, which was based on two specimens from Howick ( Broun 1893). In order to stabilize this name, a lectotype and one paralectotype are here designated from the material of Xylophilus obscurus located in the BMNH. Pic (1901) provided an unnecessary new name H. brouni , because the name “ obscurus ” which was a variety of Xylophilus pruinosus Kiesenwetter named by Pic (1892). This species is now a member of Cobososia Collado & Alonso-Zarazaga (see Nardi 2007; Alonso-Zarazaga 2010). Xylophilus pictipes is Broun species 2065 based on a single specimen from Howick ( Broun 1893). The male holotype was confirmed in the BMNH. The morphological differences between X. obscurus (two female specimens) and X. pictipes (one male specimen) appear to be those associated with males and females and X. pictipes is therefore synonymized herein.

Natural history. This is a relatively widespread and very common species, found on the main islands and on the Chatham Islands. It has been collected primarily using Malaise traps and flight intercept traps (FITs). Specimens have additionally been collected by beating both during the day and at night beating mixed forest vegetation, specifically from Coprosma grandifolia Hook. f., Melicytus ramiflorus , Pittosporum eugenioides A. Cunn. A few specimens have also been collected from pitfall traps and by sweeping Asparagus asparagoides (L.) Druce. Specimens have also been collected from fungus, including one from an unidentified sooty mold and another from Grifola collensoi (Berk.) G. Cunn.

Distribution. North Island : Northland (ND), Auckland (AK), Coromandel (CL), Waikato (WO), Bay of Plenty (BP), Gisborne (GB), Taranaki (TK), Taupo (TO), Rangitikei (RI), Wanganui (WI), Wellington (WN), and Wairarapa (WA). South Island : Marlborough Sounds (SD), Nelson (NN), Marlborough (MB), Buller (BR), North Canterbbury (NC), Westland (WD), Mid Canterbury (MC), Mackenzie (MK), Otago Lakes (OL), Fiordland (FD), Southland (SL), and Stewart Island (SI). Offshore island : Chatham (CH).

Type material examined. Xylophilus obscurus . Lectotype, female ( BMNH): “2066 // Paparoa // New Zealand / Broun Coll. / Brit. Mus. / 1922-482. // Xylophilus / obscurus [handwritten] // LECTOTYPE [female symbol] / “ Xylophilus ” / obscurus Brn. / (= brouni Pic ) [handwritten] / det. J.C. Watt / 1985”. Paralectotype, here designated ( BMNH): “2066 // Howick // New Zealand. / Broun Coll. / Brit. Mus. / 1922-482. // PARALECT. [female symbol] / “ Xylophilus ” / obscurus Brn. / (= brouni Pic ) [handwritten] / det. J.C. Watt / 1985”. Xylophilus pictipes . Holotype, female ( BMNH): “2065 // Howick // New Zealand / Broun Coll. / Brit. Mus. / 1922-482. // Xylophilus / pictipes // HOLOTYPE [female symbol] / “ Xylophilus ” / pictipes Brn. [handwritten] / det. J.C. Watt / 1985”.

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 13A–H. Zenascus obscurus, scanning electron micrographs. (A) head, frontal view; (B) antenna; (C) pronotum (D) proleg; (E) metatibia; (F) metaventrite; (G) abdomen; (H) tergite VII.