Yes, ARBOVIRUSES is a Scrabble word!

Letter values in Scrabble US: A 1, R 1, B 3, O 1, V 4, I 1, R 1, U 1, S 1, E 1, S 1.

Is it a valid word?

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

a large heterogeneous group of RNA viruses divisible into groups on the basis of the virions; they have been recovered from arthropods, bats, and rodents; most are borne by arthropods; they are linked by the epidemiologic concept of transmission between vertebrate hosts by arthropod vectors (mosquitoes, ticks, sandflies, midges, etc.) that feed on blood; they can cause mild fevers, hepatitis, hemorrhagic fever, and encephalitis

Not playable in Scrabble US: ARBORVIRUS.