Visible spectral distribution of shadows explains why blue targets with a high reflectivity at 460 nm are attractive to tsetse flies

Tsetse flies are known to be attracted by blue fabrics with a high reflectivity at 460 nm. As the visible spectral distribution of shadows has a maximum at around 460 nm it is suggested that the response to blue is due to the search of tsetse flies for shadows to seek for potential hosts, resting sites or cover.