Abstract: A trap (1) is described which is substantially cylindrical in shape having a base (2), side wall (3) and a removable upper portion (4) which has an upper surface (7) substantially concave in shape. An open-topped mesh basket (6) rests on a mesh (5) support within the trap (1). A light (14) is positioned just above the upper surface (7) of the upper portion (4) which, when energized, attracts the insect to be exterminated. The trap (1) is approximately two thirds filled with water (16) which is then pumped from within the body of the trap to create a substantially helical flow of liquid over the upper surface (7) of the upper portion (4) as it returns to the body of the trap (1). Insects attracted to the light (14) are entrained by the water (16) and are flushed down into the trap and retained within the mesh basket (6). As an alternative, the upper surface (7) can be substantially convex in shape and the water flows substantially radially over the upper surface (7) of the upper portion (4).