In a recent paper published in the Journal of Hymenoptera Research researchers investigate the effects of climate change, warming winters and changes in landscape structure on the distribution and frequency of Bombus (Hymenoptera, Apidae), the genus of bumble bees, in Hungary.
The study, co-written by partner Miklós Sárospataki from Regional Centre for Information and Scientific Development (RCISD), addresses the urgent need to update our understanding of bumble bee populations in light of climate change. With the last review of the distribution of Bombus species in Hungary conducted two decades ago, the authors fill a critical gap in knowledge by monitoring the bumble bees and updating the occurrence and threat status of the species.
In order to do that, researchers examined data collected over the past 20 years together with unpublished data from 2018 to 2021. After a thorough analysis, the results revealed that nine species require additional studies to confirm stable populations, while three species are recommended for legal protection. Encouragingly, B. argillaceus and B. haematurus exhibited intensive expansion, showcasing their ability to resist heat stress. Moreover, the widely distributed B. terrestris also displayed a high relative frequency.
These results reinforce previous research by Rasmont et al. (2015), which demonstrated a concerning decline in the relative frequency of eight species (B. barbutellus, B. confusus, B. humilis, B. muscorum, B. pomorum, B. ruderatus, B. rupestris, B. subterraneus) within the Hungarian fauna, proving the alarming influence of climate change on Bombus assemblages.
To effectively address and understand these ongoing changes, the authors recommend regular monitoring of Bombus assemblages. Furthermore, the study calls for investigation of previously unexplored areas and the verification of data for species with uncertain information.
Read the full article here.
Figure 30. from article: Bombus terrestris distribution maps of bumble bee species present in Hungary according to periods of data collection and/or publication. +: before 1954, ×: 1954–1970, empty circle: 1971–2000 and grey square: after 2000.