In one embodiment, to provide a compound of formula (III) for use as an ectoparasite control agent. In formula (III), X1 represents an unsubstituted or substituted C1-6 alkyl group or the like m1 represents an integer of 0-5 A represents an oxygen atom or a sulfur atom each of R1 and R2 independently represents a hydrogen atom, an unsubstituted or substituted C1-6 alkyl group or the like R5 represents a hydrogen atom or an unsubstituted or substituted C1-6 alkyl group B represents an oxygen atom or a sulfur atom Q2 represents an unsubstituted or X2-substituted C7-11 aralkyl group or the like and each of R3a, R3b, R4a and R4b independently represents a hydrogen atom, an unsubstituted or substituted C1-6 alkyl group or the like.
