Piona alpicola (Neuman, 1880)

Smit, Harry, Gerecke, Reinhard, Pešić, Vladimir & Gledhill, Terence, 2015, On the taxonomic state of water mite taxa (Acari: Hydrachnidia) described from the Palaearctic, part 3, Hygrobatoidea and Arrenuroidea with new faunistic data, Zootaxa 3981 (4), pp. 542-552 : 549-550

Piona alpicola (Neuman, 1880)

Piona falcigera Koenike, 1905 , nov. syn.; Piona brehmi Walter, 1910 , nov. syn.; Piona dentipes Lundblad, 1962 , nov. syn.; Piona trisetica bituberosa K. Viets, 1930 , nov. syn.

Material examined. Piona trisetica tuberosa : Holotype male, Ihl-See near Segeberg, Holstein, Germany, 24-ix- 1924, leg. Lundbeck (slide 4023, coll. Viets, SMF). Piona dentipes : Holotype male, Lake Sautusjärvi, Sweden, 10- viii-1917, leg. Lundblad (slide 5389, SMNH). Paratype female, same data as holotype (slide 5390, SMNH). Other material: male, Lake Jukkasjärvi, Sweden, 10-viii-1917, leg. Lundblad (slide 5903, SMNH); 3 males, 2 females, lake Sautusjärvi, Sweden, 10-viii-1917, leg Lundblad (tube, SMNH). Piona brehmi : male, female, Södermanland, lake Kyrksjön, Sweden, 31-v-1924, leg Lundblad (resp. slide 755, 756, SMNH); male, stream Österdalälven near Idre, Dalarna, Sweden, 8-viii-1918, leg Lundblad (slide 5918, SMNH); female.

Lundblad (1962) described Piona dentipes based on the different claw of III-L-6. This claw is straight and pointed in P. dentipes , in P. alpicola it is curved and narrowed distally. However, Lundblad (1962) did not illustrate III-L-6 of P. al picol a correctly, and the shape is dependant on the position of this leg segment. In fact it is bifurcated, but usually from a lateral view only one claw can be seen well. The shapes of the palps of the two species are similar. Lundblad (1962) illustrated the medial side of the right palp, with the distal setae of P-5 rather small, and P-4 with three distinct setal tubercles and one less distinct setal tubercle. In lateral view the left palp has four distinct setal tubercles, and P-5 with distinct distal setae (as in P. alpicola ). The female of P. dentipes is similar to the female of P. alpicola , with a semi-circular pre-genital sclerite. Therefore we conclude that the two species are conspecific. Piona brehmi has a similar III-L-6 as P. alpicola , and should therefore also be synonymized with that species. Lundblad (1962) synonymized P. trisetica tuberosa with P. brehmi (which we agree upon), but as the latter is now a synonym of P. alpicola , also the former is a synonym of P. alpicola .