Meroplius Rondani 1874

Key to the Palaearctic species of Meroplius 1. Postocellar setae absent; alula hyaline, devoid of microtrichia except along posterior edge............ M. fukuharai (Iwasa) -. Postocellar setae present; alula covered with microtrichia, as on rest of wing...................................... 2 2. Male fore femur with two black spines, distal spine curved or subtriangular (Fig. 1C)............................... 3 -. Male fore femur with two black spines, distal spine straight................................................... 4 3. Palpus black; postpedicel about twice as long as wide; male fore femur with distal spine not flattened and thickened apically................................................................................ M. fasciculatus (Brunetti) -. Palpus yellow; postpedicel about 1.1–1.3 times as long as wide; male fore femur with distal spine much flatter and thicker in apical half...................................................................... M. angulospinus sp. nov. 4. Katepisternum with densely greyish microtomentum only along upper posterior corner; male surstylus without multiple branches apically................................................................. M. minutus (Wiedemann) -. Katepisternum with densely greyish microtomentum along the entire upper margin; male surstylus with multiple branches apically............................................................................................ 5 5. Male fore femur with a flattened basal spine; male surstylus bifurcate apically....................... M. vittatus Ozerov -. Male fore femur with a not flattened basal spine (Fig. 3C); male surstylus trifurcated apically (Fig. 3E)...................................................................................................... M. trifurcus sp. nov.