CORVALLIS, Ore. — New research shows that honey bees prioritize the nutritional status of larvae when selecting a new emergency queen.
The study, funded by the U.S. Department of Agriculture and published in Scientific Reports, is the result of a collaboration between entomologists at Oregon State University and North Carolina State University.
This is the first study to thoroughly investigate the role of larval nutrition in queen selection, said Ramesh Sagili, associate professor of apiculture and Extension honey bee specialist in OSU’s College of Agricultural Sciences.
Honey bee colony health depends heavily on queens, making their production critical. When a queen dies, worker bees must rear emergency queens. They select a small number of larvae from the existing brood to raise as replacements. The colony has only about six days after the last egg was laid to begin the process.
“It’s all about survival,” Sagili said. “The bees have to pick the most fit individual to lead the colony. The queen is the most vital individual in the hive.”
In the past, some researchers speculated that workers might select larvae based on genetic closeness — a form of nepotism. But this study suggests nutrition plays a more important role.
Poor queen quality remains a challenge
Poor queen quality has been one of the beekeeping industry’s top concerns over the past decade. Each year, an estimated 1.5 million honey bee queens are reared and sold in the United States.
This study offers insights that could help improve queen quality and support a struggling industry, Sagili said.
Previous research showed that worker bees can detect differences in larval hunger. Building on this, the OSU research team tested whether the nutritional state of larvae influences queen selection.
They established observation hives and created two groups of larvae: one deprived of brood food (royal jelly) and one adequately fed. They then observed how nurse bees responded.
The team compared two queen-rearing methods — grafting and natural — and introduced both deprived and non-deprived larvae into experimental colonies experiencing emergency queen-rearing conditions. They then measured how many queens developed to the pupation stage in each group.
Non-deprived larvae favored in natural method
In colonies allowed to rear queens naturally, significantly more queens developed from non-deprived larvae than from those that had been deprived of food. The bees prioritized well-fed larvae, regardless of whether they were genetically related to the nurses.
“The bees were still selecting larvae for queen rearing mainly based on deprived and non-deprived nutritional states,” Sagili said.
Sagili helped launch the Oregon Master Beekeeper Program in 2010 and chaired the Governor’s Task Force on Pollinator Health in 2014. He leads research at OSU’s Honey Bee Lab, which is focused on applied studies to support honey bee health and beekeepers.
Co-authors of the study include Hannah Lucas, Priyadarshini Chakrabarti, and Carolyn Breece of OSU’s Honey Bee Lab, and Brad Metz of N.C. State’s Honey Bee Queen and Disease Clinic.
Previously titled Honeybees prioritize well-fed larvae for emergency queen-rearing, study finds
