Bug doodoo
Sometimes waterdroplets on your plants can fry in the sun and cause burnt spots....perhaps this is the reason for those spots?
As for why the plant was named using a referance to the Ancient Roman deity Venus, it has nothing to do with Venus whatsoever more a social comment by botanists with reference to an aspect of the feminine form that has a fimiliarity with dionaea-it was the Age of the Enlightenment after all lol.