Bumblebees can discriminate between scent-marks deposited by conspecifics

Area of Science:

• Behavioral Ecology
• Chemical Ecology
• Insect Social Behavior

Background:

• Bumblebees (Bombus terrestris) use scent-marks for social communication.
• Previous research shows bumblebees associate scent-marks with flower reward value.
• The ability to discriminate scent-marks based on relatedness remains unexplored.

Purpose of the Study:

• To investigate bumblebees' ability to discriminate scent-marks from conspecifics of varying relatedness.
• To determine if bumblebees can differentiate between self-scent-marked, nestmate-scent-marked, and non-nestmate-scent-marked flowers.
• To assess how relatedness discrimination impacts foraging behavior.

Main Methods:

• Three experiments using Bombus terrestris exposed to artificial flowers with different scent-marks.
• Flowers were either unmarked, scent-marked by the focal bee, by nestmates, or by non-nestmates.
• Behaviors were observed when presented with pairs of scent-marked or unmarked/scent-marked flowers.

Main Results:

• Bumblebees distinguished between unmarked and self-scent-marked flowers.
• They differentiated between self-scent-marked and nestmate-scent-marked flowers.
• Discrimination was also observed between nestmate-scent-marked and non-nestmate-scent-marked flowers.
• Discrimination accuracy decreased when both flower types were scent-marked.

Conclusions:

• Bumblebees possess the sophisticated ability to discriminate between scent-marks of conspecifics based on relatedness.
• This discrimination is likely based on subtle chemical differences in scent-marks.
• The findings suggest bumblebees use relatedness cues to optimize foraging decisions and social interactions.