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ARS Home » Pacific West Area » Tucson, Arizona » Honey Bee Research » Research » Publications at this Location » Publication #343377

Research Project: Determining the Impacts of Pesticide- and Nutrition-Induced Stress on Honey Bee Colony Growth and Survival

Location: Honey Bee Research

Title: Pre-almond supplemental forage improves colony survival and alters queen pheromone signaling in overwintering honey bee colonies

Author
item Carroll, Mark
item Meikle, William
item Mcfrederick, Quinn - University Of California
item Rothman, Jason - University Of California
item Brown, Nicholas
item Weiss, Milagra
item Ruetz, Zachary
item Chang, Erica

Submitted to: Apidologie
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/5/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary: Honey bee colonies experience long-term nutritional stress when nectar and pollen are unavailable during winter and early spring. Beekeepers often feed colonies with sugar and pollen substitutes to improve winter and early spring nutrition. We tested supplemental forage (flowering plants planted to feed bees) as an alternative mid-winter food source for honey bees. Overwintering bee colonies were given access to the flowering mustard plant rapini for one month (January) before almond pollination (February) and monitored through April 2016. Worker bees were infected with high levels of the gut parasite Nosema ceranae throughout the experiment. Unsupplemented colonies experienced much higher colony mortality than forage-supplemented colonies. Most unsupplemented colonies failed during almond pollination when worker flying activity was very high. Supplemented and unsupplemented colonies did not differ in colony performance (total adult worker mass, brood cell area, stored pollen cell area) or individual worker health (body mass, hypopharyngeal gland protein content, Nosema ceranae infection rate). Colonies that failed during the almond pollination showed poorer hive temperature control during the forage treatment period than colonies that survived almond pollination. Queens from supplemented colonies also gave off higher amounts of queen pheromones that attract workers to feed and groom the queen. Supplemented queens released higher amounts of the Queen Retinue Pheromone (QRP) compounds methyl oleate (MO) and 1-hexadecanol (PA) and the Queen Mandibular Pheromone (QMP) compound homovanillic alcohol (HVA) after forage supplementation than unsupplemented queens. Queens that release more QMP and QRP compounds may recruit more retinue workers for queen feeding and queen care during spring colony expansion. These results suggest that mid-winter supplemental forage can reduce colony mortality of honey bee colonies used in almond pollination. This study also suggests that forage supplementation can improve colonies under conditions that commercial colonies experience before almond pollination.

Technical Abstract: Honey bee colonies experience long-term nutritional stress when nectar and pollen are unavailable during winter and early spring. Beekeepers often supplement colony food stores with sugar and pollen substitutes to improve winter and early spring nutrition. We examined supplemental forage (flowering plants planted to feed bees) as an alternative mid-winter food source for honey bees. Overwintering bee colonies were given access to the flowering mustard plant rapini for one month (January) before almond pollination (February) and monitored through April 2016. Worker bees were chronically infected with high levels of the gut parasite Nosema ceranae throughout the experiment. Unsupplemented colonies experienced much higher colony mortality than forage-supplemented colonies. Most unsupplemented colonies failed during almond pollination when worker flying activity was very high. Supplemented and unsupplemented colonies did not differ in colony performance (total adult worker mass, brood cell area, stored pollen cell area) or individual worker health (body mass, hypopharyngeal gland protein content, Nosema ceranae infection rate). Colonies that failed during the almond pollination showed poorer colony thermoregulation (hive temperature control) during January than colonies that survived almond pollination. Queens from supplemented colonies also released higher amounts of queen pheromones that attract workers to feed and groom the queen. Supplemented queens released higher amounts of the Queen Retinue Pheromone (QRP) compounds methyl oleate (MO) and 1-hexadecanol (PA) and the Queen Mandibular Pheromone (QMP) compound homovanillic alcohol (HVA) after forage supplementation than unsupplemented queens. Queens that release more QMP and QRP compounds may recruit more retinue workers for queen feeding and queen care during spring colony expansion. These results suggest that mid-winter supplemental forage can reduce colony mortality of honey bee colonies used in almond pollination. This study also suggests that forage supplementation can improve colonies at durations (one month) and colony densities (20 colonies/acre forage) that commercial colonies experience in holding yards before almond pollination.