Yes, CHALCIDS is a Scrabble word!

Letter values in Scrabble US: C 3, H 4, A 1, L 1, C 3, I 1, D 2, S 1.

Is it a valid word?

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

any of various tiny insects whose larvae are parasites on eggs and larvae of other insects; many are beneficial in destroying injurious insects

Also: chalcid fly, chalcid wasp.

Not playable in Scrabble US: CHALCIDFLY.