Zelandobates occidentalis Smit & Pešić, 2020 —,

SmitK, Harry & PešićK, Vladimir, 2024, New records of rare water mites from New Zealand, with the description of a new genus (Acari: Hydrachnidia), Acarologia 64 (2), pp. 602-611 : 610

Zelandobates occidentalis Smit & Pešić, 2020 — n. syn.

New records — South Island. 1(juv.)/0/0, Ten Mile Creek, Paparoa NP, N of Greymouth, 42°20.370′ S, 171°16.350′ E, 16 m asl, 22.xii.2022 ; 1/0/0, Jackson River, S of Haast, 44°06.734′

S 168°35.635′ E, 53 m asl, 28.xii.2022 ; 1(juv.)/0/1, Hollyford River, Fiordland NP, 44°48.614′

S, 168°02.229′ E, 550 m asl., 4.i.2023 ; 0/1/0, Upper course Acheron River, interstitial, crossing Lyndon Road, Kurowai Torlese Tussocklands Park, 43°19.733′ S 171°40.478′ E, 795 m asl,

13.i.2023 ; 1(juv.)/0/0, Lewis River at Deer Valley Campsite along Lewis Pass Road, 42°24.278′

S, 172°23.814′ E, 806 m asl, 20.i.2023. 2/0/0, Lewis River, interstitial, at Deer Valley Campsite, 42°24.278′ S, 172°23.814′ E, 806 m asl, 20.i.2023 ; 1/0/0, Caution Creek, Fox Glacier Track,

43°29.584′ S 170°01.690′ E, 277 m asl, 12.ii.2023.

Remarks — Recently Smit and Pešić (2010) described two Zelandobates species from

New Zealand, Z. tongariro , from a single male from North Island, and Z. occidentalis from South Island. Following the original description of the latter species, Z. tongariro differs by (1) anterolateral platelets located lateral to anterodorsal plate and a pair of glandularia at the anterior margin of anterodorsal plate separated, not fused with the latter plate as in occidentalis, (2) a pair of small, elongated platelets and two pairs of glandularia located lateral on each side of genital field separated, not fused to each other as in occidentalis, (3) Vgl-2 and excretory pore situated immediately posterior to genital field, not fused with posterior margin of the genital field as in occidentalis. Newly collected material from this study reveals a significant variability in the degree of dorsal and ventral sclerotization. Most of the collected specimens have a dorsum with a large unpaired anterior plate with the postocularia and three pairs of glandularia as described in the original description Z of. occidentalis (see Figure 10A in Smit and Pešić 2020). In one male from Lewis stream, found together with an individual which has a large unpaired anterior plate with three pairs of glandularia, the anterolateral platelets lateral to the anterodorsal plate and a pair of glandularia at the anterior margin of the anterodorsal plate were not fused with the latter plate matching the condition found in type T of. tongariro

(see Figure 8A, D in Smit and Pešić 2020). In all specimens we checked in this study (which were generally smaller than the specimens from the original descriptions of tongariro and occidentalis), a pair of small, elongated platelets and two pairs of glandularia located lateral on each side of genital field were separated, and Vlg2 and the excretory pore were not fused with the genital field (see Figure 4 ). Therefore, based on the new evidence and taking into account page priority in the descriptions of the abovementioned species, we propose to synonymize Z. occidentalis with Z. tongariro .

Distribution — Known from North and South Island.

Figures

Figure 4 Zelandobates tongariroSmit & Pešić, 2020, male, Lewis River at Deer Valley Campsite: posterior part of the ventrum. Scale bar = 100 μm.