This invention relates to compositions of one or more compounds that incorporate one or more allyl sulfide, allyl disulfide or allyl polysulfide moieties, or one or more allyl sulfide, allyl disulfide or allyl polysulfide moieties and one or more hydroxyl groups, used in effective amount in formulations, including emulsions, to repel blood-feeding ectoparasitic arthropods, including mosquitoes, and to deter them from landing and feeding when applied to the skin, clothing or environment of animals, including humans. Said compounds can include, but are not limited to, 8-allyl-sulfanyloctan-1-ol. This invention also relates to compositions comprising one or more of said compounds in further combination with other arthropod repellent and deterrent compounds, including vanillin. These compounds may be formulated with inert ingredients to form a liquid, gel, paste, soap, spray, aerosol or powder.
