The full effect of this treatment takes from a few hours to as long as 4 days. The pesticide remains active for weeks to eliminate the hatching brood.
Although, bees may be seen near the entry to the treated area until the hive is dead. This is due to disorientation from the hive odor changing and being queenless. After this is complete, the hive entry is to be left open for 2 weeks or more so that the brood that hatches will be exposed to the pesticide. The pesticide then becomes harmless after 30 days, depending on weather conditions.