green bottle fly

A flash of a wing in sunlight contains all that a male green bottle fly looking for love needs to know about its potential mate. Results of a new analysis of female green bottle flies shows that they can communicate their sex, age, and even their level of interest by adjusting their wing beat, or wing flash frequency, while flying in sunlight. For example, a wing flash frequency of 178 Hz is characteristic of single young females, but a frequency of 212, 235 or 266 Hz indicates young males, old females and old males, respectively. Additionally, young single females use sunlight as a beacon for future lovers, which can be detected by males, whose complex visual systems and bigger eyes help them recognize the females’ signals. The researchers also found low mating frequency on cloudy days, reinforcing their wing flash theory.


Courtney Eichorn, Michael Hrabar, Emma C. Van Ryn, Bekka S. Brodie, Adam J. Blake and Gerhard Gries

Corresponding author:

Gerhard Gries, Department of Biological Sciences, Simon Fraser University, Vancouver, Email:

Original paper published in BMC Biology on February 14, 2017.