This is a great photo of a beetle initiating flight. The photographer has captured the moment when the posterior limbs are pushing off of the substrate (even insects initiate flight by leaping - Nachtigall and Wilson, 1967; Nachtigall, 1968; 1978; Schouest et al., 1986; Trimarchi and Schneiderman, 1993; 1995). There is also an obvious upward bend of the wings and a lot of twist.
These sorts of momentary wing shape changes (here caused by the rapid opening of the folded wings from under the elytra) are important features in the initiation of circulation and lift on the wings of small flyers, particularly insects, but are still relatively understudied. Some of the major groundwork in this area was laid out by Young et al. in 2009:
"Insect wings are complex structures that deform dramatically in flight. We analyzed the aerodynamic consequences of wing deformation in locusts using a three-dimensional computational fluid dynamics simulation based on detailed wing kinematics. We validated the simulation against smoke visualizations and digital particle image velocimetry on real locusts. We then used the validated model to explore the effects of wing topography and deformation, first by removing camber while keeping the same time-varying twist distribution, and second by removing camber and spanwise twist. The full-fidelity model achieved greater power economy than the uncambered model, which performed better than the untwisted model, showing that the details of insect wing topography and deformation are important aerodynamically. Such details are likely to be important in engineering applications of flapping flight."
The full paper from which that abstract is taken can be found here: http://www.sciencemag.org/content/325/5947/1549.abstract
(It is in Science
, so the full paper is sadly paywalled.)
If you're looking for a great book on insect flight biomechanics, incidentally, this is the best one out there: http://press.princeton.edu/titles/6881.html
. It might make a good a winter holiday gift for an entomologist in the family...
Thanks to +Jitte Groothuis
for posting the amazing photograph.