A combustible pesticidal product is disclosed which comprises a structural element formed from a cardboard having a thickness of at least 0.75 mm, a density of 450-850 kgm.sup.3 and consisting of 1 or more plies, the cardboard including: an alkali or alkaline earth metal nitrate or nitrite in an amount of from 0 to 1.83% w/w, or an alkali or alkaline earth carbonate or bicarbonate in an amount of from 0.02 to 7.0% w/w; one or more mineral silicates in an amount of from 0.01 to 8.0% w/w; a phosphate in an amount of from 0.01 to 0.40% w/w and selected from the group consisting of diammonium phosphate, monoammonium phosphate, triammonium phosphate and mixtures thereof; a boron compound in an amount of from 0.001 to 0.92% w/w (as boron) and selected from the group consisting of boric acid, sodium tetraborate hydrous, sodium borate, potassium borate, calcium borate, zinc perborate, boronatrocalcite and mixtures thereof; one or more pesticides; and optionally a perfume and/or a dye, which product on combustion emanates the pesticide into the atmosphere. Typically the combustible product will be a mosquito coil which has been impregnated with one or more insecticides effective against mosquitoes. On combustion of the coil, insecticide is emanated into the atmosphere for a period of at least 4 hours. However, the coils of the invention may be active against mosquitoes for 8 hours or more.