The present invention provides a bipyridine compound having an excellent efficacy for controlling harmful arthropods represented by formula (I): [wherein R1 represents a C2-C10 haloalkyl group, etc.； R2 represents a C1-C6 alkyl group optionally having one or more halogen atoms, etc.； R3 represents a C1-C6 chain hydrocarbon group, etc.； R6 represents a C1-C6 alkyl group optionally having one or more halogen atoms, etc.； n represents 0, 1 or 2； p and q represent independently of each other 0, 1, 2, or 3] or N-oxide thereof, and a composition comprising the same.
