The Link Between Phototaxis & Worker Physiology in Bumblebees

Authors: Daniil Grytsiuk, Margarita Orlova, Bryn Dewey

SUNY Campus: Binghamton University

Presentation Type: Poster

Location: UU 111

Presentation #: 69

Timeslot: Session A 9:00-10:00 AM

Abstract: In eusocial insects such as bumblebees, workers divide labor, with foragers collecting food while nest workers care for brood care and food distribution within the colony. This variation in worker roles may be associated with physiological differences, including traits related to reproductive potential and task specialization. Phototaxis is the innate movement toward or away from light and may be linked to worker-level physiological variation, specifically hypopharyngeal gland development, and oocyte size. Hypopharyngeal glands play a crucial role in colony function as the nest workers’ glands are highly active, producing protein-rich secretion used for larvae feeding, and for foragers, gland activity decreases and instead produces enzymes that aid in nectar processing. Since foragers experience greater light exposure than nest workers, variation in phototaxis could correspond to physiological traits influencing task specialization. However, their relationship to foraging behavior in B. impatiens remains uncertain. To investigate this, we conducted two 2-minute phototaxis trials with worker bumblebees, followed by measurements of the hypopharyngeal gland and oocyte size. A correlation would link sensory biases to worker physiology, while no correlation suggests differentiation may depend on social or environmental factors. Our study examines whether phototaxis variation corresponds with worker physiology and sensory biases in labor division.