Submitted to: Entomology Today
Publication Type: Popular Publication
Publication Acceptance Date: 4/1/2019
Publication Date: 4/1/2019
Citation: Melicher, D.M. 2019. Road trip: How hive transportation puts stress on honey bees. Entomology Today. https://entomologytoday.org/2019/04/01/road-trip-hive-transportation-stress-honey-bees/.
Technical Abstract: The pollination services provided by honey bees (Apis mellifera) have broad economic impacts and are necessary for the production of a diversity of important crops. Management practices, including long-distance transportation, contribute to high annual hive losses. Multiple times in a season, hives are transported by truck long distances to locations with highly variant climates and inconsistent resource availability which causes multiple stresses and reduces the health of the colony. To test how temperature may contribute to transportation stress, hives were equipped with internal temperature sensors and placed at different locations and orientations on the trailer during transport. We found that internal hive temperature varies significantly based on hive location and orientation. Hives near the front and rear of the trailer and those oriented toward the center aisle experience much greater variation in internal temperature than those located near the middle. These hives experience significant temperature stress, some lose their ability to thermoregulate temporarily, and a subset does not recover thermoregulation during the duration of transportation. Colony size prior to shipping significantly affects thermoregulation during shipping, bees lost after shipping, and colony survival. Additionally, we profile gene expression in A. mellifera prior to departure, immediately after arrival, and after a recovery period to identify enriched pathways and transcriptional responses to transportation. Functional and enrichment analysis identified an increase in methylation and a corresponding decrease in ribosomal and protein-folding activity. Pheromone and odorant-binding transcripts were up-regulated after transportation. After a recovery period, transcripts corresponding to defense response, immune system activity, and heat shock proteins decreased, while production of antibiotic peptides increased. We conclude that less protected hives experience considerable temperature stress which may be caused by increases in turbulent air flow in the front and rear of the truck. Transportation stress should be considered an important component of annual colony losses which can be mitigated with improved management strategies.