Juvenile hormone titer in capped worker brood of Apis mellifera and reproduction in the bee mite Varroa jacobsoni.

Juvenile hormone (JH) titers were recorded from fifth instar worker larvae of Apis mellifera carnica, Apis mellifera lamarckii, and Africanized honeybees kept under temperate and tropical climatic conditions. No differences in hormone titer according to honeybee race or climatic conditions were determined. However, the rate of reproduction of the ectoparasitic mite, Varroa jacobsoni, on larvae of the different honeybee races was highly variable. The possible role of honeybee JH in control of the parasite's reproduction is discussed.