There is disclosed an adhesive barrier for crawling insects, comprising a flexible sheet of material having an adhesive on at least one side, with a peel-off liner protecting the adhesive surface. The flexible sheet of material is shaped to form a self-standing adhesive barrier when its first and second side edges are overlapped and bonded together, the self-standing barrier having angled side walls and first and second openings of a different size, at least one of the first and second openings adapted to be placed on a flat surface without any gaps. In an embodiment, the flexible sheet forms a self-standing adhesive barrier in the shape of a cone, with a large opening at one end, and a smaller opening at the other end. At least one opening is adapted to be placed on a flat surface without any gaps.
