Researchers have constructed a replica of a swallowtail butterfly to learn the secrets of how this big-winged insect takes flight.
Researchers have built and flown a replica of a swallowtail butterfly to see exactly how this puzzlingly big-winged, slow-flapping insect soars.
The results could inspire the design of future aircraft based on the swallowtail's distinctive mode of flying.
Swallowtails have giant wings relative to the size and weight of their bodies. These unique butterflies' front wings also partially overlap their back wings, restricting the freedom of motion as well as the frequency of their wings when flapping.
In a trait they do share with other butterflies, swallowtails also lack stabilizing tail wings like those found on airplanes. These fins would serve to dampen the up-and-down motion of the butterflies' fuselage-esque body in flight as each pump of their wings gives them a boost (picture how a butterfly bobs over a sunny meadow).
Given this setup, swallowtails' ability to control how they fly appears to be rather limited, with their bodies moving passively rather than actively responding to in-flight aerodynamics, as is common in insects with differing wing arrangements.
Hiroto Tanaka, a postdoctoral fellow at Harvard University and lead author of a new study, said he and his co-author were "interested in the meaning of such a way of flight" and wondered why in the course of evolution this flying style would emerge.
To investigate how the the swallowtail gets around just with simple flapping motions, Tanaka constructed a lifelike "ornithopter" that matched the dimensions of the butterfly.