Device for trapping flying insects

A device for trapping flying insects, which device comprises a substrate, first and second storage means for the substrate, a radiation source, and an exposure zone in which radiation emitted from the source is incident upon a portion of the substrate, the first storage means being arranged to store a supply of the substrate from which successive portions can be advanced to the exposure zone, the second storage means being arranged to store successive portions of the substrate withdrawn from the exposure zone, and the arrangement being such that radiation emitted from the source is reflected from the portion of the substrate in the exposure zone, or is transmitted through that portion, so as to attract insects onto, that portion, and at least a part of the surface area of that portion is adhesive so that insects attracted by the radiation adhere thereto, and wherein the device also comprises advancing means for drawing successive portions of the substrate from the first storage means to the exposure zone and withdrawing successive portions from the exposure zone to the second storage means, and control means arranged to so operate the advancing means that the substrate is advanced intermittently to an extent sufficient for a fresh portion of the substrate to occupy the exposure zone.