Lifecycle

The lifecycle of tropilaelaps mites is similar to varroa – they both have a reproductive phase and a dispersal phase (also called the phoretic phase). During the reproductive phase, a female tropilaelaps mite (foundress mite) enters a honey bee brood cell that is about to be capped. She then lays 1-4 eggs which will hatch within 12 hours of being laid – both females and males. During their development, the mite larvae feed on the haemolymph of the honey bee pupae. Typically, the daughter mites will mate before exiting the cell, but mating can occur in open cells or even outside of the brood cell. When the honey bee has finished developing and exits the cell, this triggers the start of the dispersal phase.

The phoretic phase is when the fully developed mites spread. As the adult bee emerges from its cell, the tropilaelaps mites will attach themselves to the bee for a ride, but unlike varroa, they are unable to feed on them, so their lifespan is very short outside of a cell - more research on this topic is needed for confirmation. During this phase, the mites can transfer to other cells and hives, infecting other colonies and potentially other apiaries. Since there is a brood break over the winter in Canada (and tropilaelaps mites require brood cells to survive and reproduce), it was previously assumed that tropilaelaps mites may not be able to survive the winter. However, this hypothesis has been questioned lately as some areas where tropilaelaps have become established are assumed to have winter brood breaks [7].