why do some insects look metallic?


Example 1: green bottle fly. https://upload.wikimedia.org/wikipedia/commons/7/71/Green_bottle_fly_2013-05-26.jpg

Example 2: cetonia aurata (metallic green beetle). https://upload.wikimedia.org/wikipedia/commons/a/ad/Cetonia-aurata.jpg

I found an [article](https://royalsocietypublishing.org/doi/full/10.1098/rsif.2017.0129) explaining how the metallic sheen of those insects works, but it doesn’t explain why such a trait would be naturally selected in the first place. What advantage do those insects get?

In: Biology

Not an expert but I’ll take a stab at it. My hunch would be that for this particular species it aids in attracting a mate for reproduction as many evolutionary traits tend to do. I’m not sure why this would be the case for these insects but given the function of why they look shiny (reflecting certain polarized light), that could make them more visible to mates or perhaps less visible to certain predators.