Yes, LARVAE is a Scrabble word!

Letter values in Scrabble US: L 1, A 1, R 1, V 4, A 1, E 1.

Is it a valid word?

LARVAE is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

the immature free-living form of most invertebrates and amphibians and fish which at hatching from the egg is fundamentally unlike its parent and must metamorphose