Fig. 1.

Directional coincidence of the movements of shimmering bees and of the preying wasp. a Experimental giant honeybee nest in quiescent state. b Three frames (ff 81–83; fps = 50 Hz) document a wasp on prey flying just above the bees’ nest and provoking shimmering waves; the wasp marked in the centre of the white circle (f 81) and in the centre of the yellow and red circles (ff 82,83) respectively; the white and yellow points mark the position of the wasp’s thorax in respective frames before; yellow lines give the nest contours. c Differential images (∆ff 81–82, ∆ff 82–83) displaying segmented motions (Δlum > 5) as white spots. Flight movement of the wasp was documented in the centre of the white circle (∆ff 81–82) and of the red circle (∆ff 82–83), respectively. d The cross-points quantify the centres of the momentary motions of wasp (red) and shimmering (blue) as evaluated in the differential image ∆ff 80–81; in image ∆ff 81–82, the arrows give the movement vectors as the connections of the cross points at ∆ff 80–81 and ∆ff 81–82