Abstract: The invention relates to a method for attracting flying insects, particularly mosquitoes, for the purpose of trapping or killing them, which comprises releasing at least one chemical attractant for the insects including carbon dioxide, by reacting with water or other aqueous medium, a mixture of ingredients (such as sugar and yeast) which has previously been maintained in a substantially oxygen-free environment and which have the ability to interact with each other in presence of water or other aqueous medium, so as to generate the at least one chemical attractant. The invention also includes an essentially air-proof sealed package containing a mixture, substantially free of contact with oxygen, of the type described; the mixture also constitutes per se, an aspect of the invention.