A device to kill harmful insects, such as mosquitoes, comprising one or more structures (6A, 6B, 6C ), each having at least one opening (30A, 30B, 30C), applied, at least partially, at at least one wall (9) of a space (8A) where it is present at least one human being or animal (8) or lure, while at the remaining surfaces of the space (8A) a structure is present that does not allow passing through of insects, such as a structure of glass, plastic, wood, masonry and/or mosquito-nets (131)； of the said structures (6A, 6B, 6C ) at least one is provided of at least one opening wide enough, or that can be set wide enough, to let said harmful insects pass through and of the said structures (6A, 6B, 6C ) at least one is provided of one or more startable motions capable of killing or severely injuring said harmful insects.
