The elongated backs of moths’ wings are really essential for protection from bats. In this respect informs Florida Museum of Natural History.
Many moths and nocturnal butterflies have oddly shaped wings – long strips of unusual shape running down their backs. They look beautiful to many people, but scientists have long sought to understand the practical role they play. In recent years, evidence has emerged that the “tails” are made of ultrasonic reflective material, so while hunting, bats catch a bright signal source, tearing off a piece of the wing, but the butterfly itself survives.
Juliet Rubin and her colleagues decided to experimentally test the consistency of this theory. Saturnia moon butterflies (moon moths) participated in the experiments, which showed significant growth on the tips of the wing. The authors wanted to know if there was another explanation for this shape of the wings. Initially, during the experiments in the aviary, it turned out that the “tail” does not play a decisive role in reproduction – females approximately equally preferred males, which cut off the posterior parts of the wings and are normal. This refutes the competing hypothesis that the main purpose of the unusual wings is to attract a partner for insemination.
The biologists next tested whether the presence of a “tail” impairs the survival of daytime butterflies as they are preyed upon by birds that cannot echolocate. The authors wrapped the mealworms in confectionery dough in the shape and size of moon moth bodies and fitted real wings, half with rear overhangs. They hid these puppet moths among branches and leaves in an aviary and then released the Carolina wren there. It turns out that the birds are also indifferent to the presence of a “tail” and eat both butterflies with the same frequency.
Thus, scientists were able to disprove competing ideas and the existence of “side effects” in this adaptation, disproving the theory that this wing form originated.