The honey bee (Apis mellifera) is integral to the human agricultural enterprise and is currently facing a variety of threats to its health, including disease. Efforts to protect the honey bee against the Varroa mite and other diseases are hindered by the inability to effectively distinguish feral from managed honey bees. Feral honey bees have experienced intense natural selection for resistance to colony pests and parasites and may provide a strong source of resistance genes. Genetic testing is typically unreliable given often-extensive interbreeding between feral and managed colonies. I evaluated a diagnostic test based on stable carbon isotopic ratios that holds promise for identifying feral versus managed honey bees. Carbon isotopes have long been used to determine honey adulteration with added sugars, and this method works on the same principle, based on the fact that managed colonies are nearly always fed some supplemental sugar. I set up four types of experimental colony types: feral, managed with no supplemental feed, managed with supplemental feed, and managed with 13C labeled glucose added to supplemental feed. I analyzed carbon isotopic ratios in the tissues of individual bees using Isotope Ratio Mass Spectrometry. There was a significant difference between the isotopic signatures of colonies receiving supplemental feed and unfed feral colonies, demonstrating that there is a detectable fractionation of carbon isotopes in honey bee development. However, this difference only persisted for a few weeks after supplemental feeding was removed, suggesting that stable carbon isotopic ratios cannot be used to differentiate feral and managed bees on all timescales in all situations. This study highlights the potential for future ecological studies with a greater understanding of temporal turnover of carbon isotopic signals.
Table of Contents
Mechanisms for Rapid Turnover of Heavy Signatures...13
Applications of Isotope Analysis in Honey Bees...17
About this Honors Thesis
|Committee Chair / Thesis Advisor|
|Distinguishing feral and managed honey bees (Apis mellifera) using stable carbon isotopes ()||2018-08-28||