Fig. 4. Four successive frames from high-speed video (scale bar 3 mm) showing tegminal positions within the time course of the (closing) AM pulse pattern in Myopophyllum n. sp. The insect is oriented upward. The position of the right wing scraper region, visible through semitransparent wing cells of the left, is marked by a red arrow; coloured broken lines show where in the oscillogram time course the frame was obtained. (A) CW velocities are associated with each frame: the wings lose velocity before the production of a pulse. Scale bar, 2 ms. (B) There is a conspicuous displacement of the wings during the production of a pulse and the CWV increases to 142 mm s^-1. (C) The wings close again more slowly during the silent interpulse interval and CWV drops to 82 mm s^-1; during this time interval the scraper is relocated. (D) The new pulse is produced with a conspicuous displacement of the wings; CWV increases to 118 mm s^-1.