Natures Wonders: noisy wing insects (Introduction)

by David Turell , Monday, November 13, 2017, 19:43 (2567 days ago) @ David Turell

Some much camouflage they can only be found by following their sound at night, and only the males are noisy:

https://www.sciencedaily.com/releases/2017/11/171113095612.htm

"A new species of bushcricket which mimics dead leaves to the point of near invisibility and sings so loud humans can hear it has been examined for the first time using advanced technologies to reveal the unusual acoustic properties of its wings.

"Scientists investigating the newly-described species, named Typophyllum spurioculis in reference to the vivid orange eye spots on its legs and its necrotic-looking wings, found that when the males sing the entire wing resonates at the frequency of the call -- something which does not happen in other species of bushcrickets.

"Usually the resonating call of a bushcricket is localised to the region where the sound originates, and is created by a plectrum on the right wing being plucked by a tooth-covered file on the left wing to produce sound vibrations. The plectrum is connected to a drum-like structure that works as a speaker to radiate and amplify the signal.

"Significantly, the research team from the University of Lincoln, UK, found that in Typophyllum spurioculis, it is actually the whole wing, which resonates and amplifies the generated sound signals -- and that song is so loud it is audible to humans.

"The scientists also found that the females are larger than the males and also remain silent, with only the males employing their unusual acoustic abilities. Both sexes have wing regions that resemble damaged, discoloured leaves which provide excellent camouflage in the dense foliage of the South American rain forests, and are almost impossible to spot.

"In another twist on the conventional rules of nature, researchers also found that the bright orange spots, which sit at the base of the bushcricket's legs, are not to deter predators, but instead are likely to be involved in visual communication between the sexes. This is to be examined in future studies.

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"The study was led by entomologist Dr Fernando Montealegre-Z from the University of Lincoln's School of Life Sciences. He said: "We wanted to find out more about this species, and we were very pleased to find an abundance of both sexes in the Cloud Forest of Colombia and Ecuador, something we had not been able to find before.

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"'The unusual whole-wing-resonance might partly explain why the male's song is particularly loud and also in the range audible to the human ear, while its closest relatives are all singing at higher frequencies which we cannot detect with our ears.

Comment: This is a local adaptation to a particular forest. How did this insect get to just the right coloration? Is it God at work?