Hydrachna bilobata Halík, 1940

Smit, Harry, 2014, Australian water mites of the genus Hydrachna Müller, with the description of five new species (Acari: Hydrachnidia: Hydrachnidae), Zootaxa 3827 (2), pp. 170-186 : 171

Hydrachna bilobata Halík, 1940

Material examined. Hydrachna laceriscutata— Male holotype, North Portland Dam, Victoria, Australia, 26 -xi- 1936, leg. F. Linder (slide 2979, NHRS-GULI 9032, SMNH). Queensland. 0/ 1 /0, Emu Creek at Clancy’s Camping Area, Benarkin State Forest, 26 º 58.334 S 152 º 0 9.916 E, alt. 162 m a.s.l., 3 -xi- 2005. Northern Territory. 0/ 1 /0, Billabong Yellow Waters, Kakadu NP, 21 -vii- 1994. Western Australia. 1 (juvenile)/0/ 3, Palm Pool, Millstream- Chichester NP, 23 º 34 ’ 2.85 ” S 117 º 2 ’ 32.10 ” E, 15 -viii- 1994.

Remarks. Lundblad ( 1947) synonymized H. laceriscutata Lundblad, 1941 with H. bilobata , but Cook ( 1986) was of the opinion that H. laceriscutata should stand as a separate species. I examined the male holotype, and it has the dorsal shield typical for H. bilobata (very long dorsal plate nearly as long as the idiosoma, anteriorly with lateral extensions). Cook ( 1986) based his conclusions on the more lobate genital field of the male, but in mounted specimens this is dependent on the position in the slide. Therefore I support Lundblad’s ( 1947) conclusion that H. laceriscutata is a junior synonym of H. bilobata . The female H. bilobata of Lundblad ( 1947) does not belong to this species, but to H. novaehollandica n. sp. (see there). The juvenile male from Western Australia ( 1367 long) lacks the posterior extension of the dorsal plate. Previously known from Victoria, New South Wales and Queensland.