Downesatax Vidrine, 1992

Smit, Harry, 2008, Australian Unionicola (Acari: Hydrachnidia: Unionicolidae), with the description of two new subgenera and eight new species, Zootaxa 1674, pp. 1-26 : 5

Subgenus Downesatax Vidrine, 1992

Downesatax Vidrine, 1992: 463 .

Smithatax Vidrine, 1992: 463 new syn.

Vidrine (1992) erected the subgenera Downesatax and Smithatax for a number of small Unionicola species. Species of these two subgenera have a very similar genital field, but differ in leg setation, especially of the first leg. Species of Downesatax have short leg setae, while those of Smithatax have long leg setae, but not on tubercles, as stated by Vidrine (1992, 1996). With the description of three more species ( U. longipalpis n.sp., U. latiseta n.sp. and U. curvipalpis n.sp.), the differences between these subgenera have become blurred. There are three species with the first leg with long, heavy setae ( U. minutissima , U. alpa , U. longipalpis ), one species with the first leg with shorter heavy setae ( U. vidrinei ) and two species with the first leg with a reduced number of setae, which are not as heavy as in the previous species ( U. latiseta , U. curvipalpis ). Therefore I synonymise the two subgenera. The heavy setae of the first leg of species belonging to the subgenus Downesatax are not on tubercles, as in the larger species, e.g. those of the subgenera Edwardsatax , Hexatax or Giselatax . Setal tubercles of PIV of the newly formed subgenus vary from large ( U. minutissima , U. latiseta , U. longipalpis ), to small ( U. alpa ) to absent ( U. curvipalpis , U. vidrinei ).