Catalina P. Rodriguez Alemany and Tugrul Giray

Department of Biology, University of Puerto Rico Rio Piedras Campus, San Juan, PR, USA

INTRODUCTION: Honey bees (Apis mellifera) are economically and ecologically important plant pollinators that are highly and constantly exposed to environmental stressors including chemical pollutants, which have been linked as one source of honey bee colony losses. Stressor’s impact the bees’ complex behaviors, social organization, and division of labor that are regulated by circadian clocks and the rhythms they generate. Honey bees as bioindicators of environmental pollution are an excellent model to study the impact of ubiquitous chemical pollutants such as dibutyl phthalate (DBP) on the circadian rhythmicity ontogeny and plasticity and adult behavioral development of newly emerged workers.

METHODS: The locomotor activity of worker bees, chronically exposed to DBP during their larval or adult stages, was constantly recorded for a period of 15-20 days to determine the effects of DBP on circadian rhythmicity, behavior, and survival.

RESULTS: Chronic oral exposure to DBP throughout development affected adult locomotor activity levels, timing, and duration. Nonetheless, DBP ingestion did not influence survival and circadian rhythms periodicity and rhythm strength.

CONCLUSION: Our results indicate that environmental DBP stress exposure influences worker honey bee circadian system and behavioral development.

KEYWORDS: Circadian rhythms, dibutyl phthalate, honey bees