(Z)-8-Heptadecene reduces the reproduction of Varroa destructor in brood cells

The alkene (Z)-8-heptadecene, a semiochemical which inhibits the reproduction of Varroa destructor was tested in natural comb cells. One-hundred ng of (Z)-8-heptadecene applied under the capping of worker cells, sealed 0-15 h previously, caused a highly significant reduction both in the number of offspring (-12% reduction) and in the number of potentially mated daughters per female (-28% reduction) in single infested cells. No reduction was observed in multiple infested cells. A consistent, but not significant decrease was observed in cells treated at different times after capping. No decrease in mite reproduction was noted in cells treated 0-16 h before capping or 0-6 h after capping. However, infestation of cells treated before capping was reduced by 41%. In single infested cells in the control groups, the number of potentially mated daughters per female decreased from 1.5 in June to 0.78-0.94 in September. The proportion of treated cells emptied by bees was about 30% lower than that of control cells. (Z)-8-Heptadecene may play an important role in the host-parasite relationship.