Mosquitoes make a different sound from other flies their size because they beat their wings twice as fast as other insects their size. With such a high frequency, you knew something weird had to be going on.
The paper is:
Bomphrey, R. J., T. Nakata, N. Phillips, and S. M. Walker. 2017. Smart wing rotation and trailing-edge vortices enable high frequency mosquito flight. Nature DOI: 10.1038/nature21727
…and the puzzle is about a martini.