Mamersa rouxi Walter, 1911

Smit, Harry, 2017, New records of water mites from standing waters in Thailand, with the description of nine new species (Acari: Hydrachnidia), Zootaxa 4312 (1), pp. 69-91 : 70

Mamersa rouxi Walter, 1911

( Fig. 1 )

Mamersa paddicola Jin & Guo, 1993 —new syn.

Material examined. 1/1/0, Nong Chang Yai Reservoir , Ubon Ratchathani Province, 15° 23.874ʹ N, 104° 49.756ʹ E, 25-x-2010.

Description. See Walter (1911) and Viets (1935). Additional characters: Male idiosoma 834 long and 753 wide, female idiosoma 899 long and 826 wide. Genital field: male 259 long, and 316 wide, female 267 long and 332 wide. The male has an oblique anterior margin of the genital valve, in the female this margin is straight with a short medial extension. The pre-genital sclerite of the male is rhomboid in the male and triangular in the female. The configuration of the mediodorsal plates dg5 and dg6 (cf. Harvey1988) of both sexes is asymmetrical.

Remarks. Jin & Guo (1993) stated that, in describing M. paddicola Jin & Guo, 1993 , the new species differed in the presence of two pairs of posterolateral plates. However, they overlooked M. rouxi , a species they did not mention in the paper. Their illustrations match the description of the latter species, and we therefore propose to synonymize M. paddicola with M. rouxi . The differences in the shape of the pre-genital sclerite and the genital valves was not mentioned by Viets (1935). The species is new for the fauna of Thailand. It has been found on the Aru Islands, Sumatra and Sulawesi ( Indonesia, Wiles pers. comm.), China and Thailand (present study).

Figures

FIGURE 1. Mamersa rouxi Walter, genital field. A = female; B = male. Scale bars = 50 µm.