Scanning electron micrographs showed that wing-coupling apparatuses of the Russian wheat aphid. Diuraphis noxia (Mordvilko), are composed of a fore-wing fold and a set of spiral-shaped (or curved twice) hind-wing hamuli. We observed that the fold was simple (320 μm long, and 12 μm diameter) on the anal margin of the fore wing at the junction with vein Cu2. The hamuli were spiral-shaped structures which were different from the previous description as fish hooklike (or Clinked once) structures. The hamulus was 3.21 μm in length, and 1.45 and 0.32 μm in diameter basally and distally, respectively. The number of hamuli varied among individuals (range 2–5) and varied between left and right hind wings of some individuals. Twenty-one of 39 (54%) alatae had a symmetrical number of hamuli (either 2 or 3) on both sides of the hind wings; 18 (46%) had an asymmetrical number of hamuli. The observed variation in the number of hamuli might be a reason why these structures have not been used for aphid taxonomy. The possible causes of asymmetry of hamuli and wing-coupling mechanism are discussed according to the apparatus structure we observed.