[Berniek]

>Insects use the moon as a celestial compass cue to navigate, and mistakenly use artificial light sources instead

I think that was one of the theories being investigated by this research. The paper demonstrates that it is the actual light (of the moon or stars or sun or artificial source) they use to orientate themselves in the horizontal plain BUT that is not navigation. With a "tilt" in their orientation they will fly in circles around the light but this tilt also causes inefficiencies in their actual flight mechanism so will cause erratic directional stability as their flight path rapidly changes their spacial relationship to the light source. Whatever their navigation imperative (heat, cold pheromones,smell, sight, sound) will be affected by this spacial relationship instability.