Well, short enough not to be able to fly, but what gravid female with 'full' length wings can fly anyway? Since they are used for deimatic display, I think they are not vestigial, which I consider to be more akin to totally useless or almost gone. But even the vestigial hind wings of several flies have been found to act like a counter-balance for the main forewings.
Yeah, I think that the most apropriate biological term is "exaptation," which refers to organs or traits of a species that have become modified over time. In this case, the female mantid's wings, originally used for flight, have become atrophied and modified, often with the development of bright, warning coloration and eye spots, for deimatic display. For evolutionists, the term encompasses the belief that complex organs occuring today, such as wings or eyes, were originally more simple organs designed for a different purpose, that have been modified over time. A popular example holds that feathers were originally used to provide warmth, then for sexual display, then for flight. Darwin raised this issue in chapter vi of
The Origin of Species ("Origins of extreme perfection and complication"), but the term was not coined, I think, until the 1970's to replace "preadaptation." It was used by Stephen Gould and most famously, perhaps, by Ernest Mayr in The
Growth of Biological Thought: Diversity, Evolution, and Inheritance and more recently by the intelligent design proponent, Stephen Meyer in
Signature in the Cell: DNA and the Evidence for Intelligent Design that came out a cupla months ago.
So, there you have it, really interesting and exciting stuff, and excellent reading for those of you who will soon be forced to stay indoors during the cruel months of winter, though we in the Sunny South might enjoy it, too.
