Laboratory experiments on structure and color of a box trap affecting trap efficiency of <i>Culex pipiens</i> form <i>molestus</i>

The efficiency of box traps was evaluated by release-capture laboratory experiments of Culex pipiens form molestus. The basic box trap (13L×18W×10H cm) was composed of three parts, a shading-plate, a top board, and a collection box. The shading-plate was attached to the end of the top board at a 45-degree angle. Under the shading-plate there was a rectangular opening (9×9 cm) on the top board, which connected to the collection box. The inside wall of the collection box was covered with a sticky sheet. It is suggested that the angle of the shading-plate be between 45 and 90 degrees, the size of the opening be between 9×2 cm and 9×9 cm, the top board be black or red, and the height of trap setting position be less than 80 cm from the floor to maximize the trap efficiency. When the mosquito density was low and multiple traps were placed in a room, the relationship between the overall trapping probability (Ps) and the number of traps (n) was described by the following equation: Ps=1−(1−p)n, where p is the trapping probability achieved by a single box trap in the room.