A copulation disruption agent for sap-sucking pests which are considered the principal pests in rice cultivation is disclosed. Applying flonicamid to sap-sucking pests that affect rice cultivation disrupts the copulatory behavior thereof, effecting stable, effective pest control over the long term. This is a completely unpredicted effect, distinctly different from the simple pesticidal use of flonicamid. Disclosed are: a copulation disruption agent for sap-sucking rice parasites, said agent containing flonicamid as an active ingredient； and a method, in which said copulation disruption agent is processed, for disrupting the copulatory behavior of the aforementioned pests.
