Determining how long a viral pathogen remains infectious within honey bee hive products

Although honey bee (Apis mellifera) hive products, such as honey and pollen, have been shown to act as vehicles for honey bee-infecting viruses within apiaries, it remains unclear how long these viruses remain infectious within these hive products. To help determine this, we conducted a study to see how long Israeli acute paralysis virus (IAPV) remains infectious in sucrose solution, pollen, and honey. The sucrose solution acted as a control group to compare the pollen and honey treatments against. IAPV was spiked into sucrose solution, pollen, and honey, which were then stored at either -20°C or 34°C conditions for 1 to 4 weeks, with weekly sampling occurring. We then conducted cage trials in which adult honey bee workers were provided with one of the food treatment groups and then monitored for survivorship over a 72-hour period. Our results showed that bees exposed to IAPV-spiked sucrose solution experienced significant mortality, particularly when fed spiked sucrose solution that had been stored at -20°C for a shorter duration. In contrast, bees fed IAPV-spiked pollen or honey exhibited minimal mortality overall. This could be due to the nutritive properties of honey and pollen enhancing bee immunity and survivorship, the inhospitable nature of these substrates negatively affecting viral viability, or a combination of both. These findings offer insight for beekeepers concerned with whether their management practices contribute to the spread of viruses through the movement of food resources between colonies.