Thortus bullerensis, Leschen & Chen & Harmer, 2024

Thortus bullerensis sp. nov.

( Fig. 7 View Fig )

Type material. HOLOTYPE: ♁ ( NZAC), labelled: ‘Dublin Terrace Buller 25.11.61 leaf litter J. I. Townsend. [handwritten] // Thortus sp. nov. [handwritten] det. R. A. Crowson // Entomology Div. D.S.I.R. New Zealand / NZ Arthropod Collection Private Bag 92170 Auckland New Zealand NZAC04235080 About NZAC .’ PARATYPE ( NZAC). SOUTH ISLAND: BR: Norris Creek, Buller Road, 14 Oct 1970, litter, J.I. Townsend, [42°6.245′S, 172°12.171′E], NZAC 04272538.

Diagnosis. Thortus bullerensis sp. nov. is a unicolourous species with a well-developed eye, a narrowed frons, the gena short, the pronotum widest in the anterior 1/3, and the parasutural stria incomplete. It is most similar to T. parallelus , which has the pronotum widest at the middle and the marginal bead of the metaventrital process present. Description. Length 1.35 mm. Colour of body unicolourous red-brown, with lighter antennal club, mouthparts and legs. Body surface semiglabrous, microsculpture absent from most surfaces, very weak and present on ventral surfaces of the head, hypomeron and lateral portions of the abdominal ventrites. Dorsal setae silver, consisting of short scattered suberect and subdecumbent setae. Ventral surfaces with suberect setae; mesoventrite foveolate, not strongly impressed, disc of metaventrite with punctures variable, some more impressed than those on prosternum, punctation of abdominal ventrites 1 to 4 generally smaller or equal to those on metaventrite, setae longer at sides, punctation on ventrite 5 denser with a well-defined patch of posteriorly-directed setae. Head lengthened with short gena, subequal to length of antennomere 1; frons constricted, narrowed to width just less than half the length of antennomere 1; supra-antennal ridge with well-developed rim, bead present; vertex delimited anteriorly by a weakly transverse crenulate line, anterior surface glabrous, posterior surface with broad foveolate punctures; gular punctation deep and ovate, diameters larger than those on sides of head. Eye consisting of approximately 13 facets. Antennomere 2 barrel-shaped, wider than long, antennomere 3 subconical, longer and narrower than 2 and longer and slightly wider than 4, proportions of antennomeres 4–8 equal, antennomere 9 wider than 8 and narrower than 10 and 11, antennomere 10 transverse same width as 11, antennomere 11 longer than 10, shorter than 9 and 10 combined. Pronotum transverse, pronotal length/width ratio ~0.81, widest at apical third; anterior margin convex; anterior angles obtuse, not projecting and rounded; lateral edges weakly convex, weakly curved anteriorly, gradually converging posteriorly; pronotal disc with punctation subuniform and foveolate, shallow, absent in central disc with a broad median glabrous area, separated by a distance of up to 1–2 times their diameter and larger at the base; median impression absent; transversely depressed at basal 1/5; basomedial macropuncture present, triangulate; posterolateral angles almost right, sharp, slightly projecting posteriorly; posterior margin sinuate with a weak scutellar lobe. Prosternal process with well-developed lateral marginal beads, without longitudinal depression medially, process subparallel-sided and slightly converging posteriorly, slightly expanded posteriorly behind procoxae, apex curved, width slightly narrower than procoxa and about half total prosternal length; procoxal cavity without anterolateral notch. Scutellary shield trapezoidal and transverse, 2.1 times wider than long. Elytra about 1.37 times as long as combined width, about 1.11 times width of pronotum at greatest width, about 1.90 times length of pronotum; setation dual consisting of relatively short suberect and shorter subdecumbent setae; humeral plica present; parasutural stria present and incomplete, present to about basal 1/3; punctation less dense than pronotum, except at base where it is more impressed. Metaventrital process with anterior margin straight, marginal bead present at sides, absent at middle. Tarsi moderately slender, 5-5- 5 in female, 5-5- 4 in male, tenent setae not observed; mesotarsomeres 1–3 of subequal lengths, mesotarsomere 5 subequal to tarsomeres 1–4 combined. First abdominal ventrite with broad rounded intercoxal process, postcoxal lines long, divergent, extending middle of sclerite. Aedeagus with relatively short parameres that are fused at their bases and fixed to phallobase, paramere about as wide as long; apices asetose (?), without membranous extensions; basipenis about 2.5 times length of distipenis; distipenis about 1.60 times longer than width, lateral lobes separated, basal plate absent; internal sac with a pair of short slender endophallites.

Etymology. The specific epithet is taken from the Buller region; adjective.

Distribution. South Island: BR ( Fig. 21 View Fig ).

Remarks. Thortus bullerensis sp. nov. is endemic to the Buller region of the South Island. It was collected from leaf litter. The two specimens were completely disarticulated.