A pesticide delivery system integrated into an overflow drain system of a bathtub, a sink, or any other water-retaining basin. The pesticide delivery system includes a pesticide intake segment passing through a transition passage, wherein the transition passage is formed through a wall of a section of the overflow drain system. A fluid retentive seal is located between an exterior of the pesticide intake segment and the overflow conduit wall. A pesticide distribution conduit extends from a distribution end of the pesticide intake segment to a termination end. Pesticide can be discharged through a pesticide delivery port located at an end of the pesticide distribution conduit or through a plurality of pesticide distribution ports spatially located along the pesticide distribution conduit. A plurality of pesticide distribution continuation conduits can be in fluid communication with the pesticide distribution conduit to distribute the pesticide along various directions and locations.