Insights into adult worker foraging dynamics within a Bombus terrestris (Hymenoptera: Apidae) colony

Bombus terrestris, an important eusocial insect, plays a vital role in providing pollination services for both wild plants and greenhouse crops. For the development of the colonies, the workers must leave the hives to collect nectar and pollen. However, limited findings about the foraging behavior of B. terrestris workers (e.g., first foraging period, total foraging duration, and daily foraging bouts). Here, radio-frequency identification (RFID) technology was used to monitor the continuously foraging behavior of B. terrestris workers during August and October, 2021 and August, 2023. The findings of our study indicate that the participation rate in the foraging activity among adult workers was 65.07%. In addition, it was observed that adult workers initiate their initial foraging activities on the second day, with the majority commencing their first foraging endeavors between the ages of 3 and 5 days. It is noteworthy that worker bees will remain within the confines of the hive for the entirety of their lifespan, if they do not begin their first foraging within the first 12 days. Our results also revealed that workers were mainly foraged from 7:00 AM to 10:00 AM and 14:00 PM to 17:00 PM in August, while, and predominantly from 12:00 to 15:00 in October. Furthermore, it was shown that foraging efficiency was notably greater during seasons marked by a plentiful availability of flower resources. This was supported by an observed rise in the frequency of daily foraging activities and the overall duration of foraging.