Friday, October 13, 2006
Beetles have evolved hard forewings as a protection to the flight wings. This enables them to use environments (such as under leaf duff or in the soil) as adults without damaging the wings. But, this advantage is balanced by the need to retract the much larger flight wings under the elytra in an organized and repeatable way.
I was watching this ladybird beetle for awhile, as it flexed its forewings (the shiny red elytra we recognize these beetles by) to reveal its flight wings in various stages of unfolding. The wings have no musculature and so the questions arises, how do they unfold . . . and refold, for that matter. The flight wings are constructed of veins connected by panels of thin cuticle, and it turns out, some rubbery protein (resilin) strategically positioned in flexible joints. The resilin gives durability to the folding areas, and also stores energy from the actual fold to power the unfolding process. The resilin also functions in flexing of the wings during flight. (Haas, Gorb, and Blickhan).
As I watched this ladybug, it was clear that bending of the abdomen is part of the mechanism that initiates the unfolding. Finally, the little truck fully extended both wings and took off from a branch tip into the wide world of the aeronautically and origamically gifted.
Small red truck becomes
airborn origami far
beyond human reach