Interspecific comparison of Apis mellifera mortality : Age at first flight and seasonal weather impact

• Main Author: Gliebus, Aivaras
• Format: Bachelor Thesis
• Language: English
• Published: Högskolan i Skövde, Institutionen för biovetenskap 2024
• Subjects: Ecology; Ekologi; Juoksengi; Northern Sweden
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-23917

Apis. m. mellifera is an important pollinator native to the northern regions of Europe. This subspecies of the Apis mellifera family has faced significant population declines in recent years, raising concerns about the far-reaching impacts on ecosystems, biodiversity, and agricultural productivity. Apart from the existing threats caused by habitat loss and pesticide exposure, Nordic brown bees are being out dominated by other imported honeybee subspecies, which are preferred by beekeepers because of their advantageous traits. There are evident differences between the living environments of the imported subspecies and the Nordic climate. Therefore, it is unexpected that the imported subspecies have been able to adapt enough to be comparable to the native Apis. m. mellifera. To understand how the imported subspecies A. m. ligustica, Apis. m. carnica, and Apis. m. x (Hybrid Buckfast) deal with Swedish weather conditions in contrast to the native Apis. m. mellifera, age at the first flight (AFF) and survival probabilities were investigated. This was done by utilizing two-year pre-collected radio frequency identification data from northern Sweden (Juoksengi), using three different weather parameters and bee AFF as predictors in the Cox proportional hazard model. These analyses were conducted to see if the survival probabilities of the native and imported subspecies were affected. The results showed different survival probabilities among the studied subspecies and years. Importantly, the two-year seasonal data provided valuable insights into the survival dynamics of the Apis mellifera subspecies, highlighting AFF and some weather fluctuations as crucial predictors of survival probabilities. While the observed results are complex and vary depending on the subspecies and yearly meteorological fluctuations, it is evident that the imported subspecies exhibit local adaptations. The results of this study, however, also suggested that the native Nordic brown bees exhibit higher tolerance for most of the tested predictors.