Queen honey bees exhibit variable resilience to temperature stress.

Area of Science:

• Apiculture and insect physiology
• Environmental stress biology
• Reproductive biology

Background:

• Extreme temperatures can compromise honey bee queen sperm viability.
• The direct effects of thermal stress on queen performance and maternal quality are not well understood.
• Understanding queen bee resilience to temperature fluctuations is crucial for beekeeping.

Purpose of the Study:

• To investigate the impact of acute cold and heat stress on honey bee queen reproductive metrics and offspring quality.
• To assess the effects of thermal stress on sperm viability, queen performance, and embryonic development.
• To evaluate the utility of known stress biomarkers in honey bee queens.

Main Methods:

• Honey bee queens were exposed to cold (4°C), hot (42°C), or control (33°C) temperatures for 2 hours in a blind field trial.
• Laying patterns, queen mass, andcallow worker mass were recorded before and after stress exposure.
• Sperm viability was measured, and proteomics were used to analyze the egg and spermathecal fluid proteomes for maternal stress effects.

Main Results:

• Cold stress significantly reduced stored sperm viability in queen honey bees.
• Neither cold nor heat stress significantly affected queen mass, laying patterns,callow worker mass, or the proteomes of eggs or spermathecal fluid.
• Previously identified heat and cold stress biomarkers were not differentially expressed, suggesting limited diagnostic utility post-stress.

Conclusions:

• Cold stress negatively impacts honey bee queen fertility, while heat stress does not show significant effects on the measured parameters.
• There is considerable variation in temperature tolerance among queen honey bees, particularly concerning fertility.
• Further research is needed to quantify the variation and heritability of temperature tolerance to enhance queen bee resilience.