Meroplius

Key to the Palaearctic species of Meroplius View in CoL

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 View FIGURE 1 )............................... 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) View in CoL

-. 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) View in CoL

-. 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 View in CoL

-. Male fore femur with a not flattened basal spine ( Fig. 3C View FIGURE 3 ); male surstylus trifurcated apically ( Fig. 3E View FIGURE 3 )...................................................................................................... M. trifurcus sp. nov.