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, 26º 58.334 S 152º 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, 23º 34’2.85” S 117º 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.