Wasserthal, L.T. (1976): Heartbeat reversal and its coordination with accessory pulsatile organs and abdominal movements in Lepidoptera. - Experientia 32: 577-578.
Haemolymph in certain Lepidoptera at rest is periodically transported from the anterior body to the abdomen and reversed by the coordinated activity of the heart, the accessory pulsatile organs and the abdomen. This oscillatory haemolymph transport is suggested to support haemolymph exchange and air ventilation in the anterior body and wings.
Intermittent activity of the accessory pulsatile organs (b, c) coordinated with the backward pulse periods of the heart (a, black bars) and abdominal ventilatory bouts