How can poor nutrition increase a honeybee colony's vulnerability to disease?

Poor nutrition significantly increases a honeybee colony's vulnerability to disease by acting as a major source of stress that compromises the bees' immune systems.21

When colonies lack access to diverse sources of nectar and pollen—often due to the use of bees for pollinating crops with low nutritional value—they experience nutritional stress. This weakened state makes the bees more susceptible to the various pathogens and parasites that are constant threats in the environment, such as Nosema species and the varroa mite.213

Furthermore, research suggests that stressors often have a synergistic effect; for example, nutritional deficiencies can exacerbate the negative impacts of pesticide exposure, which may further suppress immune function and promote the proliferation of viruses like the deformed wing virus. By maintaining optimal nutrition, beekeepers can help reduce colony stress and bolster the bees' natural defenses against these health challenges.32