Thortus luscus Leschen, Chen & Harmer, 2024, sp. nov.
Creators: name: Leschen, Richard A. B.
name: Chen, Yandong
name: Harmer, Aaron M. T.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Cryptophagidae
Thortus
Thortus luscus

description: Thortus luscus sp. nov.
(Fig. 12)
Type material. HOLOTYPE: ♁ (LUNZ), labelled: ‘NZ: 38°S 175.58°E MauRes, F:-; P:- (3363ha) #W651-013, 33cm diam litter: 72hr Berlese, Edge dist 34.7m (9.2m offset), RK Didham 19-Feb-08.’ PARATYPES (8; AMNZ, FRNZ, LUNZ, NZAC). NORTH ISLAND: WO: 1 (LUNZ), Mangatautari, 20 Nov - 17 Dec 2008, south cell outside cell, C.H. Watts, [38°2.679′S, 175°33.832′E]; 1, Mangatautari, 21 Jan - 24 Feb 2008, south cell outside cell, C.H. Watts, [38°2.679′S, 175°33.832′E], NZAC 04272535; 1, Maungatautari, 18 Dec 2010 - 20 Jan 2011, C.H. Watts, 37°58.133′, 175°33.683′E, AMNZ 86330;1 (LUNZ), Maungatautari Mountain, 18 Dec 2010 - 20 Jan 2011, C.H. Watts, 38°0′S, 175°34.8′E; 1 (LUNZ, same as holotype), Mau Reserve Forest Park (Mangatautari), 19 Feb 2008, litter, R.K. Didham, 38°0′S, 175°34.8′E; 1, Sanctuary Mountain, Maungatautari, southern enclosure, 20 Nov 2020, litter, R. Leschen, Y. Chen, 38°2.679′S, 175°33.832′E, RL2265, NZAC 03038714. BP: 1 (FRNZ), Dansey [Road Scenic] Reserve, pitfall trap OP5, C.Wardhaugh, 9 Jan - 3 Feb 2023, 38°5.417′S, 176°7.45′E; 1 (FRNZ), Endean′ s Bush native forest pitfall 1, C. Wardhaugh, 13 Dec 2022 - 9 Feb 2023, 38°9.871′S, 176°1.622′E.
Diagnosis. Thortus luscus sp. nov. is unicolourous and has a unifacetted eye. The abdominal postcoxal lines are divergent, but do not reach the middle of the disc of abdominal ventrite 1. It most closely resembles T. simplex, differing from it by having the pronotum widest at the middle and by having parasutural striae.
Description. Length 1.30–1.40 mm. Colour of body unicolourous red-brown, with lighter antennal club, mouthparts and legs. Body surface glabrous, microsculpture present on ventral surfaces and distinct on the abdominal ventrites, absent or very weak and present on lateral surfaces of the head and at the sides of the pronotum. Dorsal setae silver, consisting of short scattered decumbent setae. Ventral surfaces with suberect setae; punctation ovate on prosternum, mesoventrite foveolate and strongly impressed, disc of metaventrite with punctures variable and as impressed as those on prosternum, but generally smaller, punctation of abdominal ventrites 1 to 4 smaller or equal to those on metaventrite and lass impressed, setae not longer at sides, punctation on ventrite 5 denser with a well-defined patch of posteriorly-directed setae. Head not lengthened with relatively short gena that is subequal to the length of antennomere 1; frons constricted, narrowed to a width subequal in length to antennomere 1; supra-antennal ridge with well-developed rim, bead absent; vertex delimited anteriorly by a transverse crenulate line, anterior surface punctured, posterior surface subglabrous and irregularly foveolate; gular punctation semi-regular and ovate, diameters more or less equal to those on sides of head. Eye consisting of a single facet. Antennomere 2 barrel-shaped, slighter longer than wide, antennomere 3 subconical, about as long as slightly narrower than 2 and longer and wider than 4, proportions of antennomeres 4–8 nearly the same, antennomere 9 wider than 8 and narrower than 10 and 11, antennomere 10 transverse and about the same width as 11, antennomere 11 longer than 10, shorter than 9 and 10 combined. Pronotum transverse, pronotal length/width ratio ~1.16, widest at middle; anterior margin convex; anterior angles obtuse, rounded and not projecting; lateral edges weakly convex, converging anteriorly, gradually converging posteriorly; pronotal disc with punctation coarse and subuniform and foveolate, shallow, sparse to absent in central disc, separated by a distance of up to 1 times their diameter and larger at the base; median impression absent; transversely depressed at basal 1/5; basomedial macropuncture present but weakly indicated and elongate and may be weakly triangulate; posterolateral angles right, sharp, not or slightly projecting posteriorly; posterior margin sinuate with a weak scutellar lobe. Prosternal process with well-developed lateral marginal beads, without longitudinal depression medially, process more or less subparallel-sided, slightly expanded posteriorly behind procoxae, apex subacute, width slightly narrower than procoxa 0.5 times as long as length of prosternum; procoxal cavity without anterolateral notch. Scutellary shield subtrapezoidal and transverse, 2.3 times as wide as long. Elytra about 1.31 times as long as combined widths, about 1.11 times wider than width of pronotum, about 1.70 times longer than length of pronotum; setation uniform consisting of relatively short decumbent setae; humeral plica present; parasutural stria present, incomplete and extending to about basal 1/3; punctation less dense than pronotum, but at base more impressed. Metaventrital process with anterior margin weakly curved, marginal bead weakly indicated at middle. Tarsi moderately slender, 5-5- 5 in female, 5-5- 4 in male, male pro- and mesotarsomeres 1–3 with tenent setae; mesotarsomeres 1–3 of subequal lengths, mesotarsomere 5 subequal to tarsomeres 1–4 combined. First abdominal ventrite with intercoxal process relatively narrowed and subacute, postcoxal lines relatively short, divergent, extending to basal 1/3 rd of sclerite. Aedeagus with relatively long parameres articulated to phallobase, paramere about 2 times as long as wide; apices somewhat truncate or subrounded, without membranous projections, unisetose; basipenis about 3.43 times as long as distipenis; distipenis about 1.76 times as long as wide, lateral lobes separated, basal plate absent; internal sac with a pair of long slender endophallites, one, at least is expanded apically.
Etymology. The specific epithet is the Latin adjective ‘ luscus ’, meaning ‘one-eyed’.
Distribution. North Island: WO, BP (Fig. 21).
Remarks. Thortus luscus sp. nov. is known from nine specimens, collected at Maungatautari, Endean’s Bush, and Dansey Road Scenic Reserve. It has been taken in pitfall traps and sifting litter and dead wood.
description: Published as part of Leschen, Richard A. B., Chen, Yandong & Harmer, Aaron M. T., 2024, Revision of flightless New Zealand Picrotini (Coleoptera: Cryptophagidae): phylogeny of Thortus, eye reduction, and rarity, pp. 455-500 in Acta Entomologica Musei Nationalis Pragae 64 (2) on pages 476-479, DOI: 10.37520/aemnp.2024.031, http://zenodo.org/record/14655048