Simple-minded? No, but I think you're missing a crucial factor.

> A larger bee would have a larger body with larger wings.
> Wouldn't the wing load per unit area be the same?

Halve the dimensions of a bee and its weight (assuming constant density)
reduces by a factor of eight, while the wing area is a quarter what it was;
therefore the wing loading per unit area is halved.

It's known as the 'square-cube law'.

Martin Hall
London UK