Genetic Evaluation of Tunisian Honeybees for In-Hives and Broods' Temperature and Relative Humidity: Critical Traits for Tolerance to Climate Changes

Honeybee colonies are essential for global food security and genetic diversity due to their critical role in pollination. Within a colony, honeybees engage in activities like honey production and maintaining hive conditions, which are vital for the colony's health and productivity. This study aimed to deepen our understanding in three key areas: (1) The ability of honeybees in the southern Mediterranean to regulate hive and brood conditions, (2) Estimation of genetic parameters for hive Temperature and Relative Humidity, and (3) Prediction of Breeding Values (PBVs) for honeybee colonies. Data on Temperature and Relative Humidity were collected from sensors placed inside hives and at the brood level over a three-year period (2021-2023). The study analyzed 22,364 records of in-hive Temperature and Relative Humidity from 118 sensors, along with 1,664 brood-level humidity records from 14 sensors. PBVs were predicted using a BLUP Animal model. The results showed that monthly variations significantly influenced both Temperature and Relative Humidity within the hives. Heritability estimates were 0.21 for in-hive temperature, 0.33 for in-hive relative humidity, and 0.22 for brood relative humidity. A high genetic correlation (0.65) between Temperature and Relative Humidity within the hives suggests shared genetic and physiological mechanisms for these traits. The study also found that 77% of in-hive Temperature records and 48% of Relative Humidity records fell within optimal ranges, indicating that many Tunisian bees effectively regulate their hive environment. Based on PBVs, 24 colonies were selected for their superior adaptation to environmental conditions. This research underscores the importance of connected beehives and their impact on honeybee management and selection. Understanding genetic parameters and trait relationships aids in improving the long-term success and productivity of honeybee populations.