Movie 2.

Acherontia atropos. During downstroke the metathoracic spiracle under contraction of the dorsolongitudinal muscles is enclosed in the intersegmental cleft. Inversely during upstroke under contraction of the dorsoventral muscles the lateral sclerites are moved backwards and the spiracle opens. Sony Alpha 9, slow motion option. The recording frame rate of 30 fps was slightly lower than the wing beat frequency of the moth 30. 24/s almost freezing the movements, generating a slow-motion effect (see Materials and Methods).