Certain embodiments of the present invention employ insect-attracting liquid mixtures, solid mixtures, liquid solutions, and solid solutions that include two or more insect-attracting substances or compounds with different physical characteristics that lead to multi-component plumes comprising component plumes with different radii and multiple chemical gradients. Additional embodiments of the present invention include multi-component insect-attracting substances that effectively target two or more different types of insects that together comprise a target group of insects, and additionally target a particular sex, in certain embodiments, or both sexes, in other embodiments, of the target insects. Many of the insect-attracting-substance embodiments of the present invention, upon controlled vaporization or release, create a multi-component, three-dimensional plume that leads insects to the source of the plume along multiple chemical-concentration gradients. The insect-attracting-substance embodiments of the present invention can be incorporated within lures, traps, and other devices and more complex substances related to insect attraction. In one embodiment of the present invention, a multi-component insect-attracting substance comprises a combination of raspberry ketone and methyl eugenol that is effective, contrary to prior expectations and results, for attracting both oriental fruit flies and melon flies.