The parasitic mite Varroa destructor Anderson and Trueman, the most serious threat to apiculture in many countries of the world, reproduces inside honeybee brood cells. Previous research, using artificial cells for rearing the mite on an Apis mellifera larva, indicated that semiochemicals affecting the reproduction of Varroa destructor are released into such cells. In order to isolate these semiochemicals, infested artificial cells were extracted with hexane and the extract fractionated twice. Several unsaturated hydrocarbons were identified in the active fraction; some of them were released in higher amounts in case of infestation and were, therefore, bioassayed for their effect on the mite's reproduction. Of five alkenes tested under laboratory conditions, (Z)-8-heptadecene, caused a 30% reduction in the mean number of offspring of mites reared in cells treated with this compound.