- Parasites such as Varroa destructor, Tropilaelaps.
- Predators, notably Aethina tumida (small hive beetle), and Vespa velutina.
- Viruses, including deformed wing virus (DWV), black queen cell virus (BCQV) and sacbrood bee virus (SBV).
- Fungi, the most common of which is Nosema.
- Bacteria that cause diseases such as American Foulbrood and European Foulbrood.
