Data from: Biomechanical drivers of the evolution of butterflies and moths with a coilable proboscis

The ability of butterflies and moths to drink nectar through a proboscis
up to 3 times longer than their body has remained a puzzle. Although
current biomechanical models suggest that the proboscis is used as a
straw, the forces required to pull liquids through these long straws would
require adaptations that have not yet been described, such as
disproportionately large muscles that create strong pressure
differentials. Our analyses revealed a common feature that allows
butterflies and moths to drink through an elongated proboscis: the
presence of bubble trains in the conduits of the feeding system. We
combined X-ray phase-contrast imaging, optical video microscopy,
micro-computed tomography, phylogenetic models of evolution, and fluid
mechanics models of bubble train formation to understand the biomechanics
of butterfly and moth feeding. Our models of evolution suggest that the
bubble train mechanism appeared in the early evolution of butterflies and
moths with a proboscis long enough to coil. We propose that the bubble
train mechanism is a key feature in the diversification of butterflies and
moths with a coilable proboscis.