Atopida lescheni sp. nov.

(Figs 1L–M, 3E, 5G–H, 13A, 17L)

Type material. Holotype, 1 ex. (NZAC): “Rapahoe \ 3.11.40 \ E. S. Gourlay ”, “var.”, “ E. S. Gourlay \ Dec. 1970 \ Ent. Div.”; paratype, 1 ex. (NZAC): same data as holotype; paratype, 1 ex. (NZAC): “SWEPT BEECH FOREST \ AND STREAM \ BY COBB RESERVOIR \ 18 DEC. 1967 \ B.M.MAY”; paratype, 1 ex. (NZAC): “ Mt Peel. 1200m \ Cobb V. Nelson \ Dec 67 \ S Bridge”, “moss”.

Diagnosis. Externally resembling other species with crenulate lateral pronotal carinae that inhabit South Island, like A. insularis sp. nov., A. tuhua sp. nov. etc. Certain identification possible only after examination of male genitalia: trigonium as long as parameroids, triangular, pointed at apex, parameres with sharp denticles on inner margins.

Description. Male. Body elongated, moderate size (TL 4.1–4.4 mm), moderately convex, surface of head and pronotum uneven. Body yellowish-brown to almost black. Punctation on head and pronotum granulate, strong and dense, punctures doughnut-shaped, touching each other, with the exception of central portion of disc, where punctures are more sparse, with shining interspaces; punctation on elytra simple, punctures separated by 0.3–0.5× diameter of a puncture. Body covered with moderately long, erect setae. Supraantennal ridges projecting to form long, triangular outgrowths (Fig. 3E). Sides of pronotum subparallel to slightly rounded, widest in half of its length, sides crenulate, anterolateral angles distinctly produced, posterolateral angles pointed. Elytra without carinae, humeri well-marked. Ventrite 5 subtriangular, with rounded apex. Penis (L 0.51 mm, W 0.26 mm) moderately elongated, with explanate lateral lobes, trigonium rather narrow, triangular, pointed at apex, as long as parameroids; parameroids elongated, apices pointing outwards, covered with numerous punctures, rounded at apices; pala triangular, a bit longer than parameroids. Tegmen (L 0.45 mm, W 0.34 mm) wide, rectangular, parameres triangular, with scarce punctures and sharp denticles on inner edges and on apices.

Female unknown.

Measurements and ratios. Males (n = 4) TL 4.10–4.35 mm (4.18 mm), PL 0.70–0.80 mm (0.73 mm), PW 1.15–1.30 mm (1.25 mm), EL 3.35–3.55 mm (3.45 mm), EW 2.00– 2.05 mm (2.03 mm), TL/EW 2.02–2.12 (2.06), PW/PL 1.63–1.86 (1.73), EL/EW 1.68–1.73 (1.70), EL/PL 4.44–4.93 (4.77), EW/PW 1.54–1.74 (1.62).

Distribution. The species is known from localities in Nelson and Buller areas of South Island (Fig. 18E).

Etymology. Dedicated to Richard A. B. Leschen, one of the leading contemporary coleopterists, who encouraged us to study New Zealand marsh beetles and helped during our New Zealand trip in 2016.

Remarks. Due to low number of known specimens, little is known on the variability of the species, which nevertheless seems to be significant, at least in colouration. Specimens from the area of Cobb Reservoir are yellowish, while those collected in Rapahoe are almost black.