The Effect of Bt Corn Pollen and Clothianidin on Honey Bees

Open Access
Taylor, Samantha Jo
Area of Honors:
Interdisciplinary in Biology and Entomology
Bachelor of Science
Document Type:
Thesis Supervisors:
  • Maryann Tomasko Frazier, Thesis Supervisor
  • Stephen Wade Schaeffer, Honors Advisor
  • Diana Lynn Cox Foster, Faculty Reader
  • clothianidin
  • Bt corn pollen
  • honey bee decline
  • Colony Collapse Disorder
Currently, 92 million acres of Bt corn are grown throughout the United States. Much of the corn crop is protected from chewing and sucking insects by the systemic neonicotinoid, clothianidin, making the exposure of honey bees (Apis mellifera) to the combination of Bt corn pollen and clothianidin a very likely scenario. Although corn is a wind pollinated crop, honey bees typically collect this abundant source of pollen in mid-summer. The objective of this study was to determine if a synergistic interaction occurs when bees consume Bt corn pollen and clothianidin, resulting in increased mortality. Two preliminary experiments were conducted that led to the use of artificial queen rearing cups as the ideal pollen feeding delivery method. Initially, newly-emerged caged bees were fed one of three pollen diets (mixed pollen, non-Bt corn pollen, and Bt corn pollen). After feeding on the pollen for nine days, each group received a 0.3ppm dose of clothianidin fed in a 50% sugar solution. The average pollen consumed per treatment group and average weight gain per treatment group were recorded throughout the first nine days of the experiment and the mortality was recorded at regular intervals throughout the clothianidin treatment period. Chi-square tests were performed between the different treatment groups to determine if the mortality was significant. Adding clothianidin to the diet significantly affected the survival of the bees independent of which pollen diet they received (Figures 11-13). No synergistic effect between Bt corn pollen and clothianidin was observed.