Thortus crowsoni, Leschen & Chen & Harmer, 2024

Thortus crowsoni sp. nov.

( Fig. 8 View Fig )

Type material. HOLOTYPE: ♀ ( NZAC, card-mounted after dissection), labelled: ‘NZ: S. Canterbury, Geraldine , Peel For. Nat. Res. under bark of Kanikoreas matais, 27. xii. 1956, SC2 R. Crowson // Entomology Div. D.S.I.R. New Zealand // NZ Arthropod Collection Private Bag 92170 Auckland New Zealand NZAC04235098 About NZAC .’

Diagnosis. Thortus crowsoni sp. nov. is a bicolourous species with a unifacetted eye and a broad body. It is most similar to T. ovalis but has well-developed punctures on the pronotum and the head and has a broader clypeal constriction, and lack of a fine, transverse line on the vertex. Description. Length 1.70 mm. Colour of body dark reddish-brown, with lighter elytra, antennal club, mouthparts and legs. Body surfaces semiglabrous, microsculpture absent. Dorsal setae silver, consisting of short scattered recurved setae. Ventral surfaces with suberect setae; punctation ovate on head and prosternum, mesoventrite foveolate, not strongly impressed, disc of metaventrite with ovate punctures that are slightly less impressed than those on prosternum, punctation of abdominal ventrites 1 to 4 generally smaller or equal to those on metaventrite, weak, 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, with length narrowed subequal to length of antennomere 1; frons wide and not constricted, narrowed to width to about equal in length to antennomere 1; supra-antennal ridge with well-developed rim, bead absent; vertex not delimited anteriorly by a weak transverse crenulate line, surface rugulose with deep punctures of mixed sizes, two rows of weak transverse rows, the largest fused with their anterior rims connected and forming a crenulate line; gular punctation deep and ovate, diameters less than those on sides of head. Eye unifacetted. Antennomere 2 barrel-shaped, slightly wider than long, antennomere 3 subconical, longer and narrower than 2 and longer and slightly wider than 4, proportions of antennomeres 4–8 nearly the same, antennomere 9 slightly wider than 8 and narrower than 10 and 11, antennomere 10 not 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 ~0.86, widest near middle; anterior margin weakly convex; anterior angles obtuse, not projecting and rounded; lateral edges weakly convex, curved anteriorly at anterior 1/3, gradually converging posteriorly; pronotal disc with punctation not uniform and foveolate, enlarged towards base, shallow, present in central disc (without a median glabrous strip), separated by a distance of up to 1 times their diameter; median impression absent; transversely depressed at basal 1/5; basomedial macropuncture absent; posterolateral angles almost right, sharp, slightly projecting posteriorly; posterior margin sinuate with a scutellar lobe. Prosternal process with well-developed lateral marginal beads, with longitudinal depression medially, process subparallel- -sided, slightly expanded posteriorly behind procoxae, apex curved, width slightly narrower than procoxa and 0.5 times length of prosternum; procoxal cavity without anterolateral notch. Scutellary shield subtrapezoidal and transverse, 1.7 times as wide as long. Elytra about 1.20 times as long as combined width, about 1.14 times greatest width of pronotum, about 1.58 times length of pronotum; setation uniform consisting of relatively short, curved setae; humeral plica absent; parasutural stria absent; punctation present, sparse and not as impressed as that on pronotum. Metaventrital process with anterior margin straight, marginal bead present at sides, absent at middle. Tarsi moderately slender, 5-5- 5 in female, male unknown; mesotarsomeres 1–3 of subequal lengths, mesotarsomere 5 slightly longer than tarsomeres 1–4 combined. First abdominal ventrite with broad rounded intercoxal process, postcoxal lines long, weakly convex, extending middle of sclerite.

Etymology. The specific epithet is a patronym for Roy Crowson, collector of the holotype, and modernist reviser of Coleoptera classification. The specimen, along with others in yellow-aged spirits, was gifted to the RABL during his first visit to Glasgow in 1992.

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

Remarks. Thortus crowsoni sp. nov. is known from a single specimen collected with specimens of Thortus ovalis . The misspelling on the label may refer either to kahikatea ( Dacrycarpus dacrydioides (A.Rich.) de Laub. ) or matai ( Prumnopitys taxifolia (Banks & Sol. ex D. Don) de Laub. ).