マルハナバチが選択する食事は理想的な食事と一致しない可能性(What a bumble bee chooses to eat may not match ideal diet)

2025-07-02 ペンシルベニア州立大学(PennState)

<関連情報>

• https://www.psu.edu/news/agricultural-sciences/story/what-bumble-bee-chooses-eat-may-not-match-ideal-diet
• https://www.sciencedirect.com/science/article/abs/pii/S0022191025000769

マルハナバチは最適な栄養選択をしているのか? Do bumble bees make optimal nutritional choices?

Etya Amsalem, Anna Cressman, Seyed Ali Modarres Hasani
Journal of Insect Physiology  Available online 20 May 2025
DOI:https://doi.org/10.1016/j.jinsphys.2025.104822

Graphical abstract

Highlights

• Bees on high-protein diets consumed more pollen but laid fewer eggs.
• Bees on high-lipid diets, regardless of type, consumed less pollen, gained less weight, and laid fewer eggs.
• Bees on low-sucrose diets consumed more nectar but gained less weight, had lower ovarian activation, and laid fewer eggs.
• Bees on glucose performed worse than those on fructose or sucrose.
• Bumble bee nutritional choices did not always align with fitness outcomes.

Abstract

Nutrition is crucial for bees, impacting their health, survival, and pollination performance in ecosystems and agriculture. Bees get essential nutrients such as carbohydrates, proteins, lipids, vitamins, and minerals, primarily from nectar and pollen. Many bee species are experiencing declines linked partially to nutritional stress, often exacerbated by climate change, pesticides, and pathogens, highlighting the need to understand and support optimal bee nutrition to mitigate these stressors. Bumble bees, such as Bombus impatient and Bombus terrestris, essential pollinators in agriculture, are known to regulate their nutrient intake. However, whether their dietary choices improve fitness is poorly understood. We tested diets with varying protein, lipid, and carbohydrate compositions, analyzing impacts on consumption, body mass, egg laying, and ovarian activation. Results showed that bees overconsumed pollen on protein-enriched diets and under consumed it on lipid-enriched and glucose-based diets. Nectar overconsumption was observed on low-concentration sucrose diets. These patterns, however, did not correspond to improved fitness, as egg laying and body mass were negatively correlated with consumption in diets enriched with protein and sugar. Ovarian activation was largely unaffected across most diets, indicating it may not be a reliable indicator of diet quality. These findings raise doubts about whether bees make optimal nutritional choices and suggest that diet consumption alone may not be a reliable indicator of their optimal diet. Alternatively, bees made the best possible decisions under circumstances that presented a lose-lose tradeoff across all the diets provided. These data can inform future studies on nutritional stress, enhance interpretations of bee diet preferences in bioassays, and guide bumble bee management practices.