Yes, COCKCHAFER is a Scrabble word!

Letter values in Scrabble US: C 3, O 1, C 3, K 5, C 3, H 4, A 1, F 4, E 1, R 1.

Is it a valid word?

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

any of various large European beetles destructive to vegetation as both larvae and adult

Also: may bug, may beetle, melolontha melolontha.