FIELD: chemistry.
SUBSTANCE: present invention relates to the use of a compound of formula I, where R is hydrogen or C1-C5 alkyl, 
is a double bond, or a salt or crystal thereof for reducing the level of ectoparasite infestation, as well as for the treatment of infestation with ectoparasites. Also disclosed is use of a composition containing a tobacco extract enriched with a compound of formula Ia to reduce the level of ectoparasite infestation.
EFFECT: invention enables to use natural compounds and compositions for controlling ectoparasites in humans and/or animals, which are characterized by a better safety profile than nicotine or synthetic neonicotinoids, due to the differential nature of action, and provides a more environmentally friendly solution.
15 cl, 6 dwg, 8 tbl
