Organic sulfur compound and its use for controlling harmful arthropod

An organic sulfur compound represented by the formula (I):

• wherein,
• R1 represents a C3-C10 alkenyl group optionally substituted with at least one halogen atom, a C3-C13 alkenyloxyalkyl group optionally substituted with at least one halogen atom, a C3-C13 alkenylthioalkyl group optionally substituted with at least one halogen atom, a C3-C10 alkynyl group optionally substituted with at least one halogen atom, a C3-C13 alkynyloxyalkyl group optionally substituted with at least one halogen atom, or a C3-C13 alkynylthioalkyl group optionally substituted with at least one halogen atom,
• R2 represents a cyano group, C(=Q)OR5 or C(=Q)N(R6)2, R3 represents a hydrogen atom, a halogen atom or a C1-C4 alkyl group,
• R4 represents a C1-C5 fluoroalkyl group,
• Q represents an oxygen atom or a sulfur atom,
• R5 represents a C1-C4 alkyl group,
• R6's each independently represents a hydrogen atom or a C1-C4 alkyl group, or two R6's are bonded to each other at their terminals to form a C2-C7 alkylene group, and
• n represents 0, 1 or 2.