The Varroa destructor mite is the honey bee’s worst pest. A new study shows that the mites prefer honey bees when they are in their nurse stage compared to newly emerged bees and forgers. The study showed that this preference for nurse bees maximises Varroa fitness, although due to the fact that each mite must find a second host (a pupa) to reproduce, the fitness benefit to the mites is not immediate but delayed. The Varroa mite is obviously a highly adapted parasite for honey bees!
Xie, X., Huang, Z. Y., & Zeng, Z. (2016). Why do Varroa mites prefer nurse bees?. Scientific Reports, 6.