Certain components of citrus fruits and oxidation products of limonene are effective deterrents, repellents and/or spatial inhibitors for mosquitoes and biting midges. The compounds that have been found to be deterrents, repellents and inhibitors for mosquitoes and biting midges are at least two of neryl acetate, citronellyl acetate, geranyl acetate, hydroxy-p-cymene, citral, α-terpineol, citronellal, linaloyl acetate, citronellol, terpen-4-ol, tetrahydrocarvone, products of oxidized oxidized limonene inclusive of d- and l-carvone, (+) limonene oxide, (−) limonene oxide, cis and trans carveol, a diol and an aldehyde. The compounds are formulated into compositions, capable of releasing a spatially deterring/repelling/inhibiting effective amount of the compound effective against mosquitoes or biting midges, in an amount greater than about 75% by weight, based on the total weight of the composition. The compositions are formulated into delivery systems or vehicles (e.g., candles).