A number of viruses affect honey bees and are significant factors in ongoing problems with colony collapse disorder (CCD) and colony losses during winter. Varroa mite (Varroa destructor), which itself can weaken colonies, can also transmit viruses to honey bees, further reducing hive strength. A recently published research study identified a new virus issue in honey bees.
It is a virus well-known to horticulture, and now recognized as a new problem in entomology. The new research indicates that tobacco ringspot virus (TRSV), a plant virus, can be transmitted to bees (including native bees, bumble bees, and honey bees). The virus is present in the pollen on infected plants. When harvested and eaten by bees, TRSV-infected pollen can transmit the virus to the colony. The virus can also be further spread by varroa mite once colonies are infected.
TRSV has a wide host range of woody and herbaceous plants, including numerous crop species. And now it has been found to make the jump to insect and mite hosts and can contribute to reduced overwintering success in honey bee colonies. One giant leap for virus-kind.
Other recent research shows that viruses can affect insect behavior, including memory, feeding, and foraging. Fascinating stuff, if a bit on the creepy sci-fi side.