Floral visitation networks and plant use of Bombus Latreille, 1802 (Hymenoptera: Apidae) species in the Marmara Region of Northwestern Turkiye

Objective: To characterize the observed flower visitation and plant-use patterns of Bombus Latreille species in the Marmara Region of northwestern Türkiye.Materials and Methods: A total of 3,737 valid Bombus–plant records obtained from 278 sampling stations were analyzed. The dataset comprised 20 bumblebee species associated with 49 plant genera belonging to 21 families. Plant genus × Bombus species and plant family × Bombus species interaction matrices were constructed, and record numbers, station-based interaction totals, associated species richness, and dominant-species shares were evaluated.Results: Onopordum, Stachys, Echium, Epilobium, and Digitalis were the most prominent plant genera, whereas Asteraceae, Lamiaceae, Boraginaceae, and Onagraceae supported broad bumblebee assemblages. The interaction structure was concentrated around several frequently visited plant genera and was supplemented by a broad pool of additional floral resources.Conclusion: The study provides a regional baseline for Bombus–plant interactions and ecological evidence that can support future monitoring and conservation planning for bumblebee communities in the Marmara Region.